Study on the structure of bridge surface of the micro Fabry-Perot cavity tunable filter

International Nuclear Information System (INIS)

Meng Qinghua; Luo Huan; Bao Shiwei; Zhou Yifan; Chen Sihai

2011-01-01

Micro Fabry-Perot cavity tunable filters are widely applied in the area of Pushbroom Hyperspectral imaging, DWDM optical communication system and self-adaptive optics. With small volume, lower consumption and cost, the Micro Fabry-Perot cavity tunable filter can realize superior response speed, large spectral range, high definition and high reliability. By deposition metal membrane on silicon chip by MEMS technology, the micro Fabry-Perot cavity has been achieved, which is actuated by electrostatic force and can realize the function of an optical filter. In this paper, the micro-bridge structure of the micro Fabry-Perot cavity tunable filter has been studied. Finite element analysis software COMSOL Multiphysics has been adopted to design the structure of the micro-bridge of the micro filter. In order to simulate the working mechanism of the micro Fabry-Perot cavity and study the electrical and mechanical characteristics of the micro tunable filter,the static and dynamic characteriastics are analyzed, such as stress, displacement, transient response, etc. The corresponding parameters of the structure are considered as well by optimizition the filter's sustain structure.

Extrinsic Fabry-Perot ultrasonic detector

Science.gov (United States)

Kidwell, J. J.; Berthold, John W., III

1996-10-01

We characterized the performance of a commercial fiber optic extrinsic Fabry-Perot interferometer for use as an ultrasonic sensor, and compared the performance with a standard lead zirconate titanate (PZT) detector. The interferometer was unstabilized. The results showed that the fiber sensor was about 12 times less sensitive than the PZT detector. Ultrasonic frequency response near 100 kHz was demonstrated. We describe the design of the fiber sensor, the details of the tests performed, and potential applications.

Pemodelan Tapis Fabry-perot pada Serat Optik dengan Menggunakan Fiber Bragg Grating

OpenAIRE

Pramuliawati, Septi; ', Saktioto; ', Defrianto

2015-01-01

Fabry-perot filter was successfully developed by a uniform Fiber Bragg Grating in fiber optic. A characterization of Bragg Grating was analyzed by using computational model with second-order of Transfer Matrix Method based on Coupled Mode Theory. The reflectivity, length of grating, and bandwidth were parametrics to determine the performance of single Bragg Grating. The transmission spectrum showed the longer grating is designed, the larger the reflectivity was produced, so that the transmiss...

Ag-protein plasmonic architectures for surface plasmon-coupled emission enhancements and Fabry-Perot mode-coupled directional fluorescence emission

Science.gov (United States)

Badiya, Pradeep Kumar; Patnaik, Sai Gourang; Srinivasan, Venkatesh; Reddy, Narendra; Manohar, Chelli Sai; Vedarajan, Raman; Mastumi, Noriyoshi; Belliraj, Siva Kumar; Ramamurthy, Sai Sathish

2017-10-01

We report the use of silver decorated plant proteins as spacer material for augmented surface plasmon-coupled emission (120-fold enhancement) and plasmon-enhanced Raman scattering. We extracted several proteins from different plant sources [Triticum aestivum (TA), Aegle marmelos (AM), Ricinus communis (RC), Jatropha curcas (JC) and Simarouba glauca (SG)] followed by evaluation of their optical properties and simulations to rationalize observed surface plasmon resonance. Since the properties exhibited by protein thin films is currently gaining research interest, we have also carried out simulation studies with Ag-protein biocomposites as spacer materials in metal-dielectric-metal planar microcavity architecture for guided emission of Fabry-Perot mode-coupled fluorescence.

TAURUS - a wide field imaging Fabry-Perot spectrometer

International Nuclear Information System (INIS)

Atherton, P.D.; Taylor, K.

1983-01-01

TAURUS, an imaging Fabry-Perot system developed by the Royal Greenwich Observatory and Imperial College London, is described. The imaging process is explained and the technique is compared with grating spectrographs. It is argued that TAURUS is superior for obtaining field information from extended emission line sources. (Auth.)

A tunable Fabry-Perot filter (λ/18) based on all-dielectric metamaterials

Science.gov (United States)

Ao, Tianhong; Xu, Xiangdong; Gu, Yu; Jiang, Yadong; Li, Xinrong; Lian, Yuxiang; Wang, Fu

2018-05-01

A tunable Fabry-Perot filter composed of two separated all-dielectric metamaterials is proposed and numerically investigated. Different from metallic metamaterials reflectors, the all-dielectric metamaterials are constructed by high-permittivity TiO2 cylinder arrays and exhibit high reflection in a broadband of 2.49-3.08 THz. The high reflection is attributed to the first and second Mie resonances, by which the all-dielectric metamaterials can serve as reflectors in the Fabry-Perot filter. Both the results from phase analysis method and CST simulations reveal that the resonant frequency of the as-proposed filter appears at 2.78 THz, responding to a cavity with λ/18 wavelength thickness. Particularly, the resonant frequency can be adjusted by changing the cavity thickness. This work provides a feasible approach to design low-loss terahertz filters with a thin air cavity.

Conductance oscillation in graphene-nanoribbon-based electronic Fabry-Perot resonators

International Nuclear Information System (INIS)

Zhang Yong; Han Mei; Shen Linjiang

2010-01-01

By using the tight-binding approximation and the Green's function method, the quantum conductance of the Fabry-Perot-like electronic resonators composed of zigzag and metallic armchair edge graphene nanoribbons (GNRs) was studied numerically. Obtained results show that due to Fabry-Perot-like electronic interference, the conductance of the GNR resonators oscillates periodically with the Fermi energy. The effects of disorders and coupling between the electrodes and the GNR on conductance oscillations were explored. It is found that the conductance oscillations appear at the strong coupling and become resonant peaks as the coupling is very weak. It is also found that the strong disorders in the GNR can smear the conductance oscillation periods. In other words, the weak coupling and the strong disorders all can blur the conductance oscillations, making them unclearly distinguished.

Fiber Fabry-Perot sensors for detection of partial discharges in power transformers.

Science.gov (United States)

Yu, Bing; Kim, Dae Woong; Deng, Jiangdong; Xiao, Hai; Wang, Anbo

2003-06-01

A diaphragm-based interferometric fiberoptic sensor that uses a low-coherence light source was designed and tested for on-line detection of the acoustic waves generated by partial discharges inside high-voltage power transformers. The sensor uses a fused-silica diaphragm and a single-mode optical fiber encapsulated in a fused-silica glass tube to form an extrinsic Fabry-Perot interferometer, which is interrogated by low-coherence light. Test results indicate that these fiber optic acoustic sensors are capable of faithfully detecting acoustic signals propagating inside transformer oil with high sensitivity and wide bandwidth.

Stable CW Single Frequency Operation of Fabry-Perot Laser Diodes by Self-Injection Phase Locking

Science.gov (United States)

Duerksen, Gary L.; Krainak, Michael A.

1999-01-01

Previously, single-frequency semiconductor laser operation using fiber Bragg gratings has been achieved by tWo methods: 1) use of the FBG as the output coupler for an anti-reflection-coated semiconductor gain element'; 2) pulsed operation of a gain-switched Fabry-Perot laser diode with FBG-optical and RF-electrical feedback'. Here, we demonstrate CW single frequency operation from a non-AR coated Fabry-Perot laser diode using only FBG optical feedback.

Effective length of short Fabry-Perot cavity formed by uniform fiber Bragg gratings.

Science.gov (United States)

Barmenkov, Yuri O; Zalvidea, Dobryna; Torres-Peiró, Salvador; Cruz, Jose L; Andrés, Miguel V

2006-07-10

In this paper, we describe the properties of Fabry-Perot fiber cavity formed by two fiber Bragg gratings in terms of the grating effective length. We show that the grating effective length is determined by the group delay of the grating, which depends on its diffraction efficiency and physical length. We present a simple analytical formula for calculation of the effective length of the uniform fiber Bragg grating and the frequency separation between consecutive resonances of a Fabry-Perot cavity. Experimental results on the cavity transmission spectra for different values of the gratings' reflectivity support the presented theory.

Multimode fiber tip Fabry-Perot cavity for highly sensitive pressure measurement.

Science.gov (United States)

Chen, W P; Wang, D N; Xu, Ben; Zhao, C L; Chen, H F

2017-03-23

We demonstrate an optical Fabry-Perot interferometer fiber tip sensor based on an etched end of multimode fiber filled with ultraviolet adhesive. The fiber device is miniature (with diameter of less than 60 μm), robust and low cost, in a convenient reflection mode of operation, and has a very high gas pressure sensitivity of -40.94 nm/MPa, a large temperature sensitivity of 213 pm/°C within the range from 55 to 85 °C, and a relatively low temperature cross-sensitivity of 5.2 kPa/°C. This device has a high potential in monitoring environment of high pressure.

Differential Radiometers Using Fabry-Perot Interferometric Technique for Remote Sensing of Greenhouse Gases

Science.gov (United States)

Georgieva, Elena M.; Heaps,William S.; Wilson, Emily L.

2007-01-01

A new type of remote sensing radiometer based upon the Fabry-Perot interferometric technique has been developed at NASA's Goddard Space Flight Center and tested from both ground and aircraft platform. The sensor uses direct or reflected sunlight and has channels for measuring column concentration of carbon dioxide at 1570 nm, oxygen lines sensitive to pressure and temperature at 762 and 768 nm, and water vapor (940 nm). A solid Fabry-Perot etalon is used as a tunable narrow bandpass filter to restrict the measurement to the gas of interest's absorption bands. By adjusting the temperature of the etalon, which changes the index of refraction of its material, the transmission fringes can be brought into nearly exact correspondence with absorption lines of the particular species. With this alignment between absorption lines and fringes, changes in the amount of a species in the atmosphere strongly affect the amount of light transmitted by the etalon and can be related to gas concentration. The technique is applicable to different chemical species. We have performed simulations and instrument design studies for CH4, "Cot isotope, and CO detection. Index Terms- Absorbing media, Atmospheric measurements, Fabry-Perot interferometers, Optical interferometry, Remote sensing.

The comparison of environmental effects on michelson and fabry-perot interferometers utilized for the displacement measurement.

Science.gov (United States)

Wang, Yung-Cheng; Shyu, Lih-Horng; Chang, Chung-Ping

2010-01-01

The optical structure of general commercial interferometers, e.g., the Michelson interferometers, is based on a non-common optical path. Such interferometers suffer from environmental effects because of the different phase changes induced in different optical paths and consequently the measurement precision will be significantly influenced by tiny variations of the environmental conditions. Fabry-Perot interferometers, which feature common optical paths, are insensitive to environmental disturbances. That would be advantageous for precision displacement measurements under ordinary environmental conditions. To verify and analyze this influence, displacement measurements with the two types of interferometers, i.e., a self-fabricated Fabry-Perot interferometer and a commercial Michelson interferometer, have been performed and compared under various environmental disturbance scenarios. Under several test conditions, the self-fabricated Fabry-Perot interferometer was obviously less sensitive to environmental disturbances than a commercial Michelson interferometer. Experimental results have shown that induced errors from environmental disturbances in a Fabry-Perot interferometer are one fifth of those in a Michelson interferometer. This has proved that an interferometer with the common optical path structure will be much more independent of environmental disturbances than those with a non-common optical path structure. It would be beneficial for the solution of interferometers utilized for precision displacement measurements in ordinary measurement environments.

Large-area Fabry-Perot modulator based on electro-optic polymers

DEFF Research Database (Denmark)

Benter, Nils; Bertram, Ralph Peter; Soergel, Elisabeth

2006-01-01

We present a large-area electro-optic Fabry-Perot modulator utilizing a photoaddressable bis-azo polymer placed between two dielectric mirrors with an open aperture of 2 cm. A modulation efficientcy of 1% at an effective modulation voltage of 20 V for a wavelength of 1.55 mymeter is demonstrated...

Folded Fabry-Perot quasi-optical ring resonator diplexer Theory and experiment

Science.gov (United States)

Pickett, H. M.; Chiou, A. E. T.

1983-01-01

Performance of folded Fabry-Perot quasi-optical ring resonator diplexers with different geometries of reflecting surfaces is investigated both theoretically and experimentally. Design of optimum surface geometry for minimum diffraction, together with the figure of merit indicating improvement in performance, are given.

Extrinsic fiber-optic Fabry-Perot interferometer sensor for refractive index measurement of optical glass

International Nuclear Information System (INIS)

Chen Jihuan; Zhao Jiarong; Huang Xuguang; Huang Zhenjian

2010-01-01

A simple fiber-optic sensor based on Fabry-Perot interference for refractive index measurement of optical glass is investigated both theoretically and experimentally. A broadband light source is coupled into an extrinsic fiber Fabry-Perot cavity formed by the surfaces of a sensing fiber end and the measured sample. The interference signals from the cavity are reflected back into the same fiber. The refractive index of the sample can be obtained by measuring the contrast of the interference fringes. The experimental data meet with the theoretical values very well. The proposed technique is a new method for glass refractive index measurement with a simple, solid, and compact structure.

Optical cascaded Fabry-Perot interferometer hydrogen sensor based on vernier effect

Science.gov (United States)

Li, Yina; Zhao, Chunliu; Xu, Ben; Wang, Dongning; Yang, Minghong

2018-05-01

An optical cascaded Fabry-Perot interferometer hydrogen sensor based on vernier effect has been proposed and achieved. The proposed sensor, which total length is ∼594 μm, is composed of a segment of large mode area fiber (LMAF) and a segment of hollow-core fiber (HCF). The proposed sensor is coated with the Pt-loaded WO3/SiO2 powder which will result in the increase of local temperature of the sensor head when exposed to hydrogen atmosphere. Thus the hydrogen sensor can be achieved by monitoring the change of resonant envelope wavelength. The hydrogen sensitivity is -1.04 nm/% within the range of 0 % -2.4 % which is greatly improved because of the vernier effect. The response time is ∼80 s. Due to its compact configuration, the proposed sensor provides a feasible and miniature structure to achieve detection of hydrogen.

A Novel, Poly-Etalon, Fabry-Perot for Planetary Research

Science.gov (United States)

Kerr, Robert B.; Doe, Richard; Noto, John

1997-01-01

In an effort to develop a mechanically robust, high throughput and solid state spectrometer several liquid crystal Fabry-Perot etalons were constructed. The etalons were tested for spectral response, radiation resistance and optical transmission. The first year of this project was spent developing and understanding the properties of the liquid crystal etalons; in the second year an intensified all-sky imaging system was developed around a pair of LC etalons. The imaging system, developed jointly with SRI International represents a unique brassboard to demonstrate the use of LC etalons as tunable filters. The first set of etalons constructed in year one of this project were tested for spectral response and throughput while etalon surrogates were exposed to proton radiation simulating the exposure of an object in Low Earth Orbit (LEO). The 2" diameter etalons had a measure finesse of approximately 10 and were tunable over five orders. Liquid crystals exposed to proton irradiation showed no signs of damage. In year two two larger diameter (3") etalons were constructed with gaps of 3 and 5 microns. This pair of etalons is for use in a high resolution, all-sky spectral imager. The WATUMI imager system follows the heritage of all sky, narrow band, intensified imagers however it includes two LC Fabry-Perot etalons to provide tunability and the ability to switch wavelengths rapidly, an import consideration in auroral airglow imaging. This work also resulted in two publications and one poster presentation. The instrument will be uniquely capable, with superior throughput and speed, to measure optical airglow of multiple emission lines in harsh conditions.

Fabry-Perot observations of [FeX] in the Cygnus Loop and IC443

International Nuclear Information System (INIS)

Ballet, J.; Rothenflug, R.; Soutoul, A.; Caplan, J.

1988-01-01

The authors present the first results of an observational program of SNRs in the coronal lines of [FeX] and [FeXIV] using Fabry--Perot spectrophotometer. These support previously published brightnesses

A Green Fabry-Perot Cavity for Jefferson Lab Hall A Compton Polarimetry

International Nuclear Information System (INIS)

Rakhman, Abdurahim; Souder, Paul; Nanda, Sirish

2009-01-01

A green laser (CW, 532 nm) based Fabry-Perot cavity for high precision Compton Polarimetry is under development in Hall A of the Jefferson Laboratory. In this paper, we present the principle and the preliminary studies for our test cavity.

Response of a New Low-Coherence Fabry-Perot Sensor to Hematocrit Levels in Human Blood

Directory of Open Access Journals (Sweden)

Małgorzata Jędrzejewska-Szczerska

2014-04-01

Full Text Available In this paper, a low-coherence Fabry-Perot sensor with a spectrally measured signal processing response to the refractive index of liquids is presented. Optical fiber sensors are potentially capable of continuous measuring hematocrit levels in blood. Low-coherence Fabry-Perot interferometric sensors offer a robust solution, where information about the measurand is encoded in the full spectrum of light reflected from the sensing interferometer. The first step in the research on such sensor is the assessment of its performance under favorable conditions, i.e., using blood samples from healthy volunteers tested in vitro. Such an experiment was conducted using a sensor comprising a superluminescent diode source, an optical spectrum analyzer working as the detection setup and a sensing Fabry-Perot interferometer providing high interference contrast. The response of this sensor was recorded for several samples and compared with the reference laboratory method. The coefficient of determination (R2 for a linear relationship between the results given by both methods was 0.978 and the difference between these results was less than 1%. The presented results suggest that further research into the performance of the sensor is merited.

Optical power equalization for upstream traffic with injection-locked Fabry-Perot lasers in TDM-PON

Science.gov (United States)

Huang, Ting-Tsan; Sheu, Lih-Gen; Chi, Sien

2010-10-01

An optical power equalization of upstream traffic in time-division-multiplexed passive optical network (TDM-PON) based on injection-locked Fabry-Perot lasers has been experimentally investigated. The upstream transmitters with stable spectrum are achieved by using an external injection light source in the optical line terminal (OLT). The different upstream powers can be equalized by injection locking a Fabry-Perot laser diode (FP-LD) biased below threshold current in OLT. The dynamic upstream power range from - 8.5 to - 19.5 db m is reduced to a 1.6 dB maximal power variation, when the uplink signal is directly modulated at 1.25 Gb/s.

Electron density and temperature study of plasmas using a millimeter-wave Fabry-Perot interferometer; Etude de la densite electronique et de la temperature de plasmas a l'aide d'un interferometre Fabry-Perot en ondes millimetriques

Energy Technology Data Exchange (ETDEWEB)

Bize, D [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1969-07-01

The contents of this article, which have been used as a basis for a State doctorate thesis, deal with research into focussing systems of the Fabry-Perot, millimetre wave type. With the help of this equipment, measurements have been made of the electronic density using interferometry in the range from 10{sup 9} to 10{sup 14} electrons/cm{sup 3}, and of the electron temperature by Thomson diffusion, of plasmas formed by laser ionisation and by high frequency. (author) [French] Le contenu de cet article, qui a fait l'objet d'une these d'Etat, se rapporte a l'etude des systemes focalisant de type Fabry-Perot en ondes millimetriques. A l'aide de ces dispositifs, on mesure la densite electronique par interferometrie dans la gamme de densites de 10{sup 9} a 10{sup 14} e/cm{sup 3} et la temperature electronique par diffusion Thomson de plasmas crees par ionisation laser et par haute frequence. (auteur)

Optimal Design of an Hourglass in-Fiber Air Fabry-Perot Microcavity—Towards Spectral Characteristics and Strain Sensing Technology

Directory of Open Access Journals (Sweden)

Qi Wang

2017-06-01

Full Text Available An hourglass in-fiber air microcavity Fabry-Perot interferometer is proposed in this paper, and its second reflecting surface of in-fiber microcavity is designed to be a concave reflector with the best curvature radius in order to improve the spectral characteristics. Experimental results proved that the extinction ratio of Fabry-Perot interferometer with cavity length of 60 μm and concave reflector radius of 60 μm is higher than for a rectangular Fabry-Perot interferometer with cavity length of 60 μm (14 dB: 11 dB. Theory and numerical simulation results show that the strain sensitivity of sensor can be improved by reducing the microcavity wall thickness and microcavity diameter, and when the in-fiber microcavity length is 40 μm, the microcavity wall thickness is 10 μm, the microcavity diameter is 20 μm, and the curvature radius of reflective surface II is 50 μm, the interference fringe contrast of is greater than 0.97, an Axial-pull sensitivity of 20.46 nm/N and resolution of 1 mN can be achieved in the range of 0–1 N axial tension. The results show that the performance of hourglass in-fiber microcavity interferometer is far superior to that of the traditional Fabry-Perot interferometer.

Microwave radiometric aircraft observations of the Fabry-Perot interference fringes of an ice-water system

Science.gov (United States)

Harrington, R. F.; Swift, C. T.; Fedors, J. C.

1980-01-01

Airborne stepped-frequency microwave radiometer (SFMR) observations of the Fabry-Perot interference fringes of ice-water systems are discussed. The microwave emissivity at normal incidence of a smooth layered dielectric medium over a semi-infinite dielectric medium is examined for the case of ice over water as a function of ice thickness and attenuation coefficient, and the presence of quarter-wavelength oscillations in emissivity as the ice thickness and frequency are varied is pointed out. Experimental observations of pronounced quarter-wavelength oscillations in radiometric brightness temperature due to the Fabry-Perot interference fringes over smooth sea ice and lake ice varying in roughness as the radiometer frequencies were scanned are then presented.

Fabry-Perot confocal resonator optical associative memory

Science.gov (United States)

Burns, Thomas J.; Rogers, Steven K.; Vogel, George A.

1993-03-01

A unique optical associative memory architecture is presented that combines the optical processing environment of a Fabry-Perot confocal resonator with the dynamic storage and recall properties of volume holograms. The confocal resonator reduces the size and complexity of previous associative memory architectures by folding a large number of discrete optical components into an integrated, compact optical processing environment. Experimental results demonstrate the system is capable of recalling a complete object from memory when presented with partial information about the object. A Fourier optics model of the system's operation shows it implements a spatially continuous version of a discrete, binary Hopfield neural network associative memory.

Fabry-Perot enhanced Faraday rotation in graphene.

Science.gov (United States)

Ubrig, Nicolas; Crassee, Iris; Levallois, Julien; Nedoliuk, Ievgeniia O; Fromm, Felix; Kaiser, Michl; Seyller, Thomas; Kuzmenko, Alexey B

2013-10-21

We demonstrate that giant Faraday rotation in graphene in the terahertz range due to the cyclotron resonance is further increased by constructive Fabry-Perot interference in the supporting substrate. Simultaneously, an enhanced total transmission is achieved, making this effect doubly advantageous for graphene-based magneto-optical applications. As an example, we present far-infrared spectra of epitaxial multilayer graphene grown on the C-face of 6H-SiC, where the interference fringes are spectrally resolved and a Faraday rotation up to 0.15 radians (9°) is attained. Further, we discuss and compare other ways to increase the Faraday rotation using the principle of an optical cavity.

Electron density and temperature study of plasmas using a millimeter-wave Fabry-Perot interferometer; Etude de la densite electronique et de la temperature de plasmas a l'aide d'un interferometre Fabry-Perot en ondes millimetriques

Energy Technology Data Exchange (ETDEWEB)

Bize, D. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1969-07-01

The contents of this article, which have been used as a basis for a State doctorate thesis, deal with research into focussing systems of the Fabry-Perot, millimetre wave type. With the help of this equipment, measurements have been made of the electronic density using interferometry in the range from 10{sup 9} to 10{sup 14} electrons/cm{sup 3}, and of the electron temperature by Thomson diffusion, of plasmas formed by laser ionisation and by high frequency. (author) [French] Le contenu de cet article, qui a fait l'objet d'une these d'Etat, se rapporte a l'etude des systemes focalisant de type Fabry-Perot en ondes millimetriques. A l'aide de ces dispositifs, on mesure la densite electronique par interferometrie dans la gamme de densites de 10{sup 9} a 10{sup 14} e/cm{sup 3} et la temperature electronique par diffusion Thomson de plasmas crees par ionisation laser et par haute frequence. (auteur)

Understanding the concept of resolving power in the Fabry-Perot interferometer using a digital simulation

International Nuclear Information System (INIS)

Juvells, I; Carnicer, A; Ferre-Borrull, J; MartIn-Badosa, E; Montes-Usategui, M

2006-01-01

The resolution concept in connection with the Fabry-Perot interferometer is difficult to understand for undergraduate students enrolled in physical optics courses. The resolution criterion proposed in textbooks for distinguishing equal intensity maxima and the deduction of the resolving power equation is formal and non-intuitive. In this paper, we study the practical meaning of the resolution criterion and resolution power using a computer simulation of a Fabry-Perot interferometer. The light source in the program has two monochromatic components, the wavelength difference being tunable by the user. The student can also adjust other physical parameters so as to obtain different simulation results. By analysing the images and graphics of the simulation, the resolving power concept becomes intuitive and understandable

Transfer functions of double- and multiple-cavity Fabry-Perot filters driven by Lorentzian sources.

Science.gov (United States)

Marti, J; Capmany, J

1996-12-20

We derive expressions for the transfer functions of double- and multiple-cavity Fabry-Perot filters driven by laser sources with Lorentzian spectrum. These are of interest because of their applications in sensing and channel filtering in optical frequency-division multiplexing networks.

Micromachined fiber optic Fabry-Perot underwater acoustic probe

Science.gov (United States)

Wang, Fuyin; Shao, Zhengzheng; Hu, Zhengliang; Luo, Hong; Xie, Jiehui; Hu, Yongming

2014-08-01

One of the most important branches in the development trend of the traditional fiber optic physical sensor is the miniaturization of sensor structure. Miniature fiber optic sensor can realize point measurement, and then to develop sensor networks to achieve quasi-distributed or distributed sensing as well as line measurement to area monitoring, which will greatly extend the application area of fiber optic sensors. The development of MEMS technology brings a light path to address the problems brought by the procedure of sensor miniaturization. Sensors manufactured by MEMS technology possess the advantages of small volume, light weight, easy fabricated and low cost. In this paper, a fiber optic extrinsic Fabry-Perot interferometric underwater acoustic probe utilizing micromachined diaphragm collaborated with fiber optic technology and MEMS technology has been designed and implemented to actualize underwater acoustic sensing. Diaphragm with central embossment, where the embossment is used to anti-hydrostatic pressure which would largely deflect the diaphragm that induce interferometric fringe fading, has been made by double-sided etching of silicon on insulator. By bonding the acoustic-sensitive diaphragm as well as a cleaved fiber end in ferrule with an outer sleeve, an extrinsic Fabry-Perot interferometer has been constructed. The sensor has been interrogated by quadrature-point control method and tested in field-stable acoustic standing wave tube. Results have been shown that the recovered signal detected by the sensor coincided well with the corresponding transmitted signal and the sensitivity response was flat in frequency range from 10 Hz to 2kHz with the value about -154.6 dB re. 1/μPa. It has been manifest that the designed sensor could be used as an underwater acoustic probe.

The low frequency facility Fabry-Perot cavity used as a speed-meter

Energy Technology Data Exchange (ETDEWEB)

Di Virgilio, A.; Braccini, S.; Ballardin, G.; Bradaschia, C.; Cella, G.; Cuoco, E.; Dattilo, V.; Fazzi, M.; Ferrante, I.; Fidecaro, F.; Frasconi, F.; Giazotto, A.; Gennai, A.; Holloway, L.H.; La Penna, P.; Lomtadze, T.; Losurdo, G.; Passaquieti, R.; Passuello, D.; Poggiani, R.; Porzio, A.; Puppo, P.; Raffaelli, F.; Rapagnani, P.; Ricci, F.; Ricciardi, I.; Solimeno, S.; Stanga, R.; Vetrano, F.; Zhou, Z

2003-09-15

Fabry-Perot cavities have many different applications as scientific instruments. In the gravitational waves research field they are extensively used to frequency stabilize lasers and to measure very small distance variations. In the present Letter a method to evaluate from the transmitted power only the relative speed and position of the mirrors of a cavity, having finesse F>40, is described. A displacement spectral sensitivity of the order of about 3x10{sup -10} m/Hz{sup -1/2} at 10 Hz is obtained with the cavity of the low frequency facility.

Calibration of Fabry-Perot interferometers for electron cyclotron emission measurements on the Tore Supra tokamak

International Nuclear Information System (INIS)

Javon, C.; Talvard, M.

1990-01-01

The electron temperature is routinely measured on TORE SUPRA using Fabry-Perot cavities. These have been calibrated using a technique involving coherent addition and Fourier analysis of a chopped black-body source. Comparison with conventional techniques is reported

Nanoporous Zeolite Thin Film-Based Fiber Intrinsic Fabry-Perot Interferometric Sensor for Detection of Dissolved Organics in Water

Directory of Open Access Journals (Sweden)

Hai Xiao

2006-08-01

Full Text Available A fiber optic intrinsic Fabry-Perot interferometric (IFPI chemical sensor wasdeveloped by fine-polishing a thin layer of polycrystalline nanoporous MFI zeolitesynthesized on the cleaved endface of a single mode fiber. The sensor operated bymonitoring the optical thickness changes of the zeolite thin film caused by the adsorption oforganic molecules into the zeolite channels. The optical thickness of the zeolite thin filmwas measured by white light interferometry. Using methanol, 2-propanol, and toluene as themodel chemicals, it was demonstrated that the zeolite IPFI sensor could detect dissolvedorganics in water with high sensitivity.

Hypersonic force measurements using internal balance based on optical micromachined Fabry-Perot interferometry

Science.gov (United States)

Qiu, Huacheng; Min, Fu; Zhong, Shaolong; Song, Xin; Yang, Yanguang

2018-03-01

Force measurements using wind tunnel balance are necessary for determining a variety of aerodynamic performance parameters, while the harsh environment in hypersonic flows requires that the measurement instrument should be reliable and robust, in against strong electromagnetic interference, high vacuum, or metal (oxide) dusts. In this paper, we demonstrated a three-component internal balance for hypersonic aerodynamic force measurements, using novel optical micromachined Fabry-Perot interferometric (FPI) strain gauges as sensing elements. The FPI gauges were fabricated using Micro-Opto-Electro-Mechanical Systems (MOEMS) surface and bulk fabrication techniques. High-reflectivity coatings are used to form a high-finesse Fabry-Perot cavity, which benefits a high resolution. Antireflective and passivation coatings are used to reduce unwanted interferences. The FPI strain gauge based balance has been calibrated and evaluated in a Mach 5 hypersonic flow. The results are compared with the traditional technique using the foil resistive strain gauge balance, indicating that the proposed balance based on the MOEMS FPI strain gauge is reliable and robust and is potentially suitable for the hypersonic wind tunnel harsh environment.

Application of Fabry-Perot velocimeter to high-speed experiments

International Nuclear Information System (INIS)

Chaw, H.H.; McMillan, C.F.; Osher, J.E.

1988-01-01

The Fabry-Perot (F-P) velocimeter is a useful instrument for measuring the velocity of objects at speeds ranging from fractions of a kilometer per second to a few tens of kilometers per second and up. Because of its immunity to electromagnetic interference and its velocity resolution, it has become the prime diagnostic tool in our electric-gun facility. Examples of its application to high speed experiments are discussed, including: electric-gun flyer studies, spallation of materials under high-speed impact, momentum-transfer studies, pressure pulse created by high-velocity impact, and detonation-wave studies in high-explosive experiments

UW Imaging of Seismic-Physical-Models in Air Using Fiber-Optic Fabry-Perot Interferometer.

Science.gov (United States)

Rong, Qiangzhou; Hao, Yongxin; Zhou, Ruixiang; Yin, Xunli; Shao, Zhihua; Liang, Lei; Qiao, Xueguang

2017-02-17

A fiber-optic Fabry-Perot interferometer (FPI) has been proposed and demonstrated for the ultrasound wave (UW) imaging of seismic-physical models. The sensor probe comprises a single mode fiber (SMF) that is inserted into a ceramic tube terminated by an ultra-thin gold film. The probe performs with an excellent UW sensitivity thanks to the nanolayer gold film, and thus is capable of detecting a weak UW in air medium. Furthermore, the compact sensor is a symmetrical structure so that it presents a good directionality in the UW detection. The spectral band-side filter technique is used for UW interrogation. After scanning the models using the sensing probe in air, the two-dimensional (2D) images of four physical models are reconstructed.

Quantum transport in bilayer graphene. Fabry-Perot interferences and proximity-induced superconductivity

International Nuclear Information System (INIS)

Du, Renjun

2015-01-01

Bilayer graphene (BLG) p-n junctions made of hBN-BLG-hBN (hexagonal boron nitride) heterostructures enable ballistic transport over long distances. We investigate Fabry-Perot interferences, and detect that the bilayer-like anti-Klein tunneling transits into single-layer-like Klein tunneling when tuning the Fermi level towards the band edges. Furthermore, the proximity-induced superconductivity has been studied in these devices with Al leads.

Application of the CCD Fabry-Perot Annular Summing Technique to Thermospheric O(1)D.

Science.gov (United States)

Coakley, Monica Marie

1995-01-01

This work will detail the verification of the advantages of the Fabry-Perot charge coupled device (CCD) annular summing technique, the development of the technique for analysis of daysky spectra, and the implications of the resulting spectra for neutral temperature and wind measurements in the daysky thermosphere. The daysky spectral feature of interest is the bright (1 kilo-Rayleigh) thermospheric (OI) emission at 6300 A which had been observed in the nightsky in order to determine winds and temperatures in the vicinity of the altitude of 250 km. In the daysky, the emission line sits on top of a bright Rayleigh scattered continuum background which significantly complicates the observation. With a triple etalon Fabry-Perot spectrometer, the continuum background can be reduced while maintaining high throughput and high resolution. The inclusion of a CCD camera results in significant savings in integration time over the two more standard scanning photomultiplier systems that have made the same wind and temperature measurements in the past. A comparable CCD system can experience an order of magnitude savings in integration time over a PMT system. Laboratory and field tests which address the advantages and limitations of both the Fabry-Perot CCD annular summing technique and the daysky CCD imaging are included in Chap. 2 and Chap. 3. With a sufficiently large throughput associated with the spectrometer and a CCD detector, rapid observations (~4 minute integrations) can be made. Extraction of the line width and line center from the daysky near-continuum background is complicated compared to the nightsky case, but possible. Methods of fitting the line are included in Chap. 4. The daysky O ^1D temperatures are consistent with a lower average emission height than predicted by models. The data and models are discussed in Chap. 5. Although some discrepancies exist between resulting temperatures and models, the observations indicate the potential for other direct measurements

Fabry-Perot measurements of barium temperature in fluorescent lamps

International Nuclear Information System (INIS)

Hadrath, S; Garner, R

2010-01-01

A scanning Fabry-Perot interferometer (FPI) is used to determine the temperature of barium atoms that are liberated from the electrodes of fluorescent lamps during their steady-state operation. Barium, a constituent of the work function lowering emitter material that is placed on the tungsten coil that forms the electrode, is liberated primarily by evaporation from the hot (∼1300 K) thermionic electrode. However, there may be situations or modes of operation in which barium is, in addition, sputtered, a condition which may lead to increased end-darkening, shortened life and increased mercury consumption in the lamp. Using the FPI diagnostic, the occurrence of sputtering is inferred when barium temperatures are much greater than the electrode temperature. The FPI diagnostic senses resonance radiation (λ = 553 nm) emitted by barium atoms excited in the low pressure discharge environment, and infers temperature from the Doppler broadened linewidth. The diagnostic has proven to be successful in a number of situations. Measurements have been made on rare gas discharges and on Hg-argon discharges for different discharge currents, gas pressures and auxiliary coil currents. Measurements are phase resolved for ac-driven discharges.

Fabry-Perot interferometer fiber tip sensor based on a glass microsphere glued at the etched end of multimode fiber

Science.gov (United States)

Chen, Weiping P.; Wang, Dongning N.; Xu, Ben; Wang, Zhaokun K.; Zhao, Chun-Liu

2017-05-01

We demonstrate an optical Fabry-Perot interferometer fiber tip sensor based on a glass microsphere glued at the etched end of a multimode fiber. The fiber device is miniature and robust, with a convenient reflection mode of operation, a high temperature sensitivity of 202.6 pm/°C within the range from 5°C to 90°C, a good refractive index sensitivity of ˜119 nm/RIU within the range from 1.331 to 1.38, and a gas pressure sensitivity of 0.19 dB/MPa.

A Fabry-Perot Interferometry Based MRI-Compatible Miniature Uniaxial Force Sensor for Percutaneous Needle Placement

OpenAIRE

Shang, Weijian; Su, Hao; Li, Gang; Furlong, Cosme; Fischer, Gregory S.

2013-01-01

Robot-assisted surgical procedures, taking advantage of the high soft tissue contrast and real-time imaging of magnetic resonance imaging (MRI), are developing rapidly. However, it is crucial to maintain tactile force feedback in MRI-guided needle-based procedures. This paper presents a Fabry-Perot interference (FPI) based system of an MRI-compatible fiber optic sensor which has been integrated into a piezoelectrically actuated robot for prostate cancer biopsy and brachytherapy in 3T MRI scan...

Passive amplification of a fiber laser in a Fabry-Perot cavity: application to gamma-ray production by Compton backscattering

International Nuclear Information System (INIS)

Labaye, F.

2012-01-01

One of the critical points of the International Linear Collider (ILC) is the polarized positrons source. Without going through further explanation on the physical process of polarized positrons production, we point out that they are produced when circularly polarized gamma rays interact with mater. Thus, the critical point is the circularly polarized gamma-ray source. A technical solution for this source is the Compton backscattering and in the end, this thesis takes place in the framework for the design of a high average power laser systems enslaved to Fabry-Perot cavities for polarized gamma-ray production by Compton backscattering. In the first part, we present this thesis context, the Compton backscattering principle and the choice for an optical architecture based on a fiber laser and a Fabry-Perot cavity. We finish by enumerating several possible applications for Compton backscattering which shows that the work presented here might benefits from technology transfer through others research fields. In the second part, we present the different fiber laser architecture studied as well as the results obtained. In the third part, we remind the operating principle of a Fabry-Perot cavity and present the one used for our experiment as well as its specificities. In the fourth part, we address the Compton backscattering experiment which enables us to present the joint utilization of a fiber laser and a Fabry-Perot cavity in a particles accelerator to generate gamma rays for the first time to our knowledge. This experiment took place in the Accelerator Test Facility (ATF). The experimental apparatus as well as the results obtained are thus presented. In the end, we summarize the results presented in this manuscript and propose different evolution possibilities for the system in a general conclusion. (author)

Lineshape Engineering in an All-Pass Ring Resonator with Backreflection Coupled to a Symmetrical Fabry-Perot Resonator

KAUST Repository

Melnikov, Vasily

2012-11-10

We derive transfer functions for an all-pass ring resonator with internal backreflection coupled to a symmetrical Fabry-Perot resonator and demonstrate electromagnetically induced transparency-like and Fano-like lineshapes tunable by backreflection in the ring resonator.

Lineshape Engineering in an All-Pass Ring Resonator with Backreflection Coupled to a Symmetrical Fabry-Perot Resonator

KAUST Repository

Melnikov, Vasily; Roqan, Iman S.

2012-01-01

We derive transfer functions for an all-pass ring resonator with internal backreflection coupled to a symmetrical Fabry-Perot resonator and demonstrate electromagnetically induced transparency-like and Fano-like lineshapes tunable by backreflection in the ring resonator.

Fabry-Perot observations of Comet Halley H2O(+)

International Nuclear Information System (INIS)

Scherb, F.; Roesler, F.L.D.; Harlander, J.; Magee-sauer, K.

1990-01-01

Fabry-Perot scanning spectrometer observations of Comet Halley's H 2 O(+) emissions have yielded 6158.64 and 6158.85 A spin doublet data at distances in the range of 0 to 2 million km from the comet heat in the antisunward direction. Cometary plasma outflow velocities were ascertained on the basis of the emissions' Doppler shifts, yielding results that were mostly but not exclusively consistent with the plasma's constant antisunward acceleration; the acceleration varied from night to night of observations over a 30-300 cm/sec range. The unusual plasma kinematics of December 14-15, 1985, and January 10, 1986, may be associated with the tail-disconnection activity observed by others. 30 refs

Characterization of a Fabry--Perot interferometer and a dc arc plasma jet for spectrochemical analysis

Energy Technology Data Exchange (ETDEWEB)

Ford, C.S.

1979-01-01

A system involving the use of a Fabry--Perot interferometer in combination with a dc arc plasma jet has been constructed and characterized for spectrochemical analysis. Parameters such as flow rate ratio, observation region, electrode composition and orifice size have been considered. Improvements such as noise reduction and dry aerosol introduction of samples were suggested.

Characterization of a Fabry--Perot interferometer and a dc arc plasma jet for spectrochemical analysis

International Nuclear Information System (INIS)

Ford, C.S.

1979-01-01

A system involving the use of a Fabry--Perot interferometer in combination with a dc arc plasma jet has been constructed and characterized for spectrochemical analysis. Parameters such as flow rate ratio, observation region, electrode composition and orifice size have been considered. Improvements such as noise reduction and dry aerosol introduction of samples were suggested

Enhanced Bulk-Edge Coulomb Coupling in Fractional Fabry-Perot Interferometers.

Science.gov (United States)

von Keyserlingk, C W; Simon, S H; Rosenow, Bernd

2015-09-18

Recent experiments use Fabry-Perot (FP) interferometry to claim that the ν=5/2 quantum Hall state exhibits non-Abelian topological order. We note that the experiments appear inconsistent with a model neglecting bulk-edge Coulomb coupling and Majorana tunneling, so we reexamine the theory of FP devices. Even a moderate Coulomb coupling may strongly affect some fractional plateaus, but very weakly affect others, allowing us to model the data over a wide range of plateaus. While experiments are consistent with the ν=5/2 state harboring Moore-Read topological order, they may have measured Coulomb effects rather than an "even-odd effect" due to non-Abelian braiding.

Fabry-Perot Interferometer Performance as Temperature Sensor for Use in Electrical Power System Applications

Directory of Open Access Journals (Sweden)

Sanjoy Mandal

2007-09-01

Full Text Available Transfer function model of the loss less Fabry-Perot cavity (FPI, developed in Z-domain is presented in this paper. Frequency response analysis of the model was carried out in MATLAB environment to explain the behavior of the interferometer and its potential as temperature sensor was studied. Analysis reveals a highly sensitive temperature sensor that can be used in electrical engineering power system applications.

Faraday-Active Fabry-Perot Resonator: Transmission, Reflection, and Emissivity

Science.gov (United States)

Liptuga, Anatoliy; Morozhenko, Vasyl; Pipa, Viktor; Venger, Evgen; Kostiuk, Theodor

2011-01-01

The propagation of light within a semiconductor Faraday-active Fabry-Perot resonator (FAFR) is investigated theoretically and experimentally. It is shown that an external magnetic field radically changes the angular and spectral characteristics of transmission, reflection and emissivity of the resonator not only for polarized, but also for unpolarized light. Suppression of interference patterns and phase inversion of the interference extrema were observed in both monochromatic and polychromatic light. The investigations were carried out for the plane-parallel plates of n-InAs in the spectral range of free charge carrier absorption. The results can be used to create new controllable optical and spectroscopic devices for investigation of Faraday-active material properties and for control of parameters of plane-parallel layers and structures.

Simultaneous wavelength and orbital angular momentum demultiplexing using tunable MEMS-based Fabry-Perot filter

DEFF Research Database (Denmark)

Lyubopytov, Vladimir; Porfirev, Alexey P.; Gurbatov, Stanislav O.

2017-01-01

In this paper, we experimentally demonstrate simultaneous wavelength and orbital angular momentum (OAM) multiplexing/demultiplexing of 10 Gbit/s data streams using a new on-chip micro-component-tunable MEMS-based Fabry-Perot filter integrated with a spiral phase plate. In the experiment, two......, maximum power penalties at the HD-FEC BER threshold relative to the 0.8 nm wavelength spacing read 0.83, 0.84 and 1.15 dB when multiplexing a Gaussian beam and OAM beams of 1st, 2nd and 3rd orders respectively. The novelty and impact of the proposed filter design is in providing practical, integrable...

Simultaneous measure of a spectral line profile and the apparatus function of a Fabry-Perot spectrometer when continuous background is present

International Nuclear Information System (INIS)

Moreno, J.M.; Quintanilla, M.; Mar, S.

1978-01-01

A deconvolution method of registered profile on a Fabry-Perot spectrometer is developed, when the actual profile of the source is a Voigt pattern together with a continuous background. The reliability and accuracy of the method is tested with theoreticaly simulated profiles. The method is applied both to measure the real line profiles and to find the Fabry-Perot parameters, as a test of its validity on studies of experimental profiles. Both measure types -source profile and apparatus function- are made simultaneously by means of analysis of the variations of registered profile, at 6438.5A Cd line and 6328A He-Ne laser line, varying the optical path between interferometer mirrors. (author) [es

Construction of an optical semiconductor amplifier starting from a Fabry-Perot semiconductor laser; Construccion de un amplificador optico de semiconductor a partir de un laser de semiconductor Fabry-Perot

Energy Technology Data Exchange (ETDEWEB)

Garcia, E.; Soto, H.; Marquez, H.; Valles V, N. [Departamento de Electronica y Telecomunicaciones, Centro de Investigacion Cientifica y de Educacion Superior de Ensenada. Km. 107, Carretera Tijuana-Ensenada, 22860 Ensenada, Baja California (Mexico)

2000-07-01

A methodology to convert a semiconductor laser Fabry-Perot (SL-FP) in a semiconductor optical amplifier (SOA) is presented. In order to suppress the cavity resonant an optical thin film coating was deposited on the facets of the SL-FP. The experiment was carried out putting on service a new monitoring technique that consist in the observation of the laser power spectrum during the antireflection coatings deposition. This allows to determine the moment were the facets reflectivity is minimum. The SOA obtained was characterized for different polarization currents. (Author)

Transversely coupled Fabry-Perot resonators with Bragg grating reflectors.

Science.gov (United States)

Saber, Md Ghulam; Wang, Yun; El-Fiky, Eslam; Patel, David; Shahriar, Kh Arif; Alam, Md Samiul; Jacques, Maxime; Xing, Zhenping; Xu, Luhua; Abadía, Nicolás; Plant, David V

2018-01-01

We design and demonstrate Fabry-Perot resonators with transverse coupling using Bragg gratings as reflectors on the silicon-on-insulator (SOI) platform. The effects of tailoring the cavity length and the coupling coefficient of the directional coupler on the spectral characteristics of the device are studied. The fabricated resonators achieved an extinction ratio (ER) of 37.28 dB and a Q-factor of 3356 with an effective cavity length of 110 μm, and an ER of 8.69 dB and a Q-factor of 23642 with a 943 μm effective cavity length. The resonator structure presented here has the highest reported ER on SOI and provides additional degrees of freedom compared to an all-pass ring resonator to tune the spectral characteristics.

Self-generation of optical frequency comb in single section quantum dot Fabry-Perot lasers: a theoretical study.

Science.gov (United States)

Bardella, Paolo; Columbo, Lorenzo Luigi; Gioannini, Mariangela

2017-10-16

Optical Frequency Comb (OFC) generated by semiconductor lasers are currently widely used in the extremely timely field of high capacity optical interconnects and high precision spectroscopy. In the last decade, several experimental evidences of spontaneous OFC generation have been reported in single section Quantum Dot (QD) lasers. Here we provide a physical understanding of these self-organization phenomena by simulating the multi-mode dynamics of a single section Fabry-Perot (FP) QD laser using a Time-Domain Traveling-Wave (TDTW) model that properly accounts for coherent radiation-matter interaction in the semiconductor active medium and includes the carrier grating generated by the optical standing wave pattern in the laser cavity. We show that the latter is the fundamental physical effect at the origin of the multi-mode spectrum appearing just above threshold. A self-mode-locking regime associated with the emission of OFC is achieved for higher bias currents and ascribed to nonlinear phase sensitive effects as Four Wave Mixing (FWM). Our results explain in detail the behaviour observed experimentally by different research groups and in different QD and Quantum Dash (QDash) devices.

Influence of laser frequency noise on scanning Fabry-Perot interferometer based laser Doppler velocimetry

DEFF Research Database (Denmark)

Rodrigo, Peter John; Pedersen, Christian

2014-01-01

n this work, we study the performance of a scanning Fabry-Perot interferometer based laser Doppler velocimeter (sFPILDV) and compare two candidate 1.5 um single-frequency laser sources for the system – a fiber laser (FL) and a semiconductor laser (SL). We describe a straightforward calibration...... procedure for the sFPI-LDV and investigate the effect of different degrees of laser frequency noise between the FL and the SL on the velocimeter’s performance...

Effect of small variations in the refractive index of the ambient medium on the spectrum of a bent fibre-optic Fabry - Perot interferometer

Energy Technology Data Exchange (ETDEWEB)

Kulchin, Yurii N; Vitrik, O B; Gurbatov, S O [Institute for Automation and Control Processes, Far-Eastern Branch, Russian Academy of Sciences, Vladivostok (Russian Federation)

2011-09-30

The phase of light propagating through a bent optical fibre is shown to depend on the refractive index of the medium surrounding the fibre cladding when there is resonance coupling between the guided core mode and cladding modes. This shifts the spectral maxima in the bent fibre-optic Fabry - Perot interferometer. The highest phase and spectral sensitivities achieved with this interferometer configuration are 0.71 and 0.077, respectively, and enable changes in the refractive index of the ambient medium down to 5 Multiplication-Sign 10{sup -6} to be detected. This makes the proposed approach potentially attractive for producing highly stable, precision refractive index sensors capable of solving a wide range of liquid refractometry problems.

Effect of small variations in the refractive index of the ambient medium on the spectrum of a bent fibre-optic Fabry - Perot interferometer

International Nuclear Information System (INIS)

Kulchin, Yurii N; Vitrik, O B; Gurbatov, S O

2011-01-01

The phase of light propagating through a bent optical fibre is shown to depend on the refractive index of the medium surrounding the fibre cladding when there is resonance coupling between the guided core mode and cladding modes. This shifts the spectral maxima in the bent fibre-optic Fabry - Perot interferometer. The highest phase and spectral sensitivities achieved with this interferometer configuration are 0.71 and 0.077, respectively, and enable changes in the refractive index of the ambient medium down to 5×10 -6 to be detected. This makes the proposed approach potentially attractive for producing highly stable, precision refractive index sensors capable of solving a wide range of liquid refractometry problems.

Construction of an optical semiconductor amplifier starting from a Fabry-Perot semiconductor laser

International Nuclear Information System (INIS)

Garcia, E.; Soto, H.; Marquez, H.; Valles V, N.

2000-01-01

A methodology to convert a semiconductor laser Fabry-Perot (SL-FP) in a semiconductor optical amplifier (SOA) is presented. In order to suppress the cavity resonant an optical thin film coating was deposited on the facets of the SL-FP. The experiment was carried out putting on service a new monitoring technique that consist in the observation of the laser power spectrum during the antireflection coatings deposition. This allows to determine the moment were the facets reflectivity is minimum. The SOA obtained was characterized for different polarization currents. (Author)

A fully computerized multi-pass Fabry-Perot interferometer for Rayleigh-Brillouin scattering experiments

International Nuclear Information System (INIS)

Bohidar, H.; Berland, T.; Boger, F.; Joessang, T.; Feder, J.

1987-01-01

The development of a Multipass Fabry-Perot interforometer assembly for use in Rayleigh-Brillouin scattering experiments is reported. The optical alignment and the scattered signal data acquisition have been completely computerized. Digital scanning and alignment strategies of the Fabry-Perot resonator have been incorporated, which makes this instrument quite unique in this respect. The high contrast (∼10 10 ) and finesse (∼50) offered by this instrument makes it possible to detect Brillouin peaks from samples that have a small Brillouin scattering cross-section. As part of this system a compatible and precision sample chamber has been constructed, which has been designed to operate in the pressure and temperature ranges of 1-1000B and 20-150 o C, respectively. The cell has been constructed to be small and compact, but it still has a large heat capacity (∼250J/K) which ensures easy and stable temperature control of the liquid sample volume which has a size of 40 mm 3 . The achievable temperature stability is +-1mK and +-2mK for operating temperatures below and above 100 o C, respectively. The pressure stability is in the range of +-0.05B of the set pressure for pressures below 100B and it is +-0.05% for higher pressures up to 1000B. Both pressure and temperature are remotely monitored and controlled by a ND/100 computer. Special care has been taken in designing the optics of the pressure cell to ensure that both the primary and secondary reflections from the entrance window, as well as the main beam, go out of the scattering region in order to achieve higher signal-to-noise ratio in actual experiments

Optical filter based on Fabry-Perot structure using a suspension of goethite nanoparticles as electro-optic material

Science.gov (United States)

Abbas, Samir; Dupont, Laurent; Dozov, Ivan; Davidson, Patrick; Chanéac, Corinne

2018-02-01

We have investigated the feasibility of optical tunable filters based on a Fabry-Perot etalon that uses a suspension of goethite (α-FeOOH) nanorods as electro-optic material for application in optical telecommunications in the near IR range. These synthetic nanoparticles have a high optical anisotropy that give rise to a very strong Kerr effect in their colloidal suspensions. Currently, these particles are dispersed in aqueous solvent, with pH2 to ensure the colloidal electrostatic stability. However, the high conductivity of these suspensions requires using high-frequency electric fields (f > 1 MHz), which brings about a high power consumption of the driver. To decrease the field frequency, we have changed the solvent to ethylene glycol which has a lower electrical conductivity than the aqueous solvent. We have built a Fabry-Perot cell, filled with this colloidal suspension in the isotropic phase, and showed that a phase shift of 14 nm can be obtained in a field of 3V/μm. Therefore, the device can operate as a tunable filter. A key advantage of this filter is that it is, by principle, completely insensitive to the polarization of the input light. However, several technological issues still need to be solved, such as ionic contamination of the suspension from the blocking layers, and dielectrophoretic and thermal effects.

Luminosity optimization schemes in Compton experiments based on Fabry-Perot optical resonators

Directory of Open Access Journals (Sweden)

Alessandro Variola

2011-03-01

Full Text Available The luminosity of Compton x-ray and γ sources depends on the average current in electron bunches, the energy of the laser pulses, and the geometry of the particle bunch to laser pulse collisions. To obtain high power photon pulses, these can be stacked in a passive optical resonator (Fabry-Perot cavity especially when a high average flux is required. But, in this case, owing to the presence of the optical cavity mirrors, the electron bunches have to collide at an angle with the laser pulses with a consequent luminosity decrease. In this article a crab-crossing scheme is proposed for Compton sources, based on a laser amplified in a Fabry-Perot resonator, to eliminate the luminosity losses given by the crossing angle, taking into account that in laser-electron collisions only the electron bunches can be tilted at the collision point. We report the analytical study on the crab-crossing scheme for Compton gamma sources. The analytical expression for the total yield of photons generated in Compton sources with the crab-crossing scheme of collision is derived. The optimal collision angle of the bunch was found to be equal to half of the collision angle. At this crabbing angle, the maximal yield of scattered off laser photons is attained thanks to the maximization, in the collision process, of the time spent by the laser pulse in the electron bunch. Estimations for some Compton source projects are presented. Furthermore, some schemes of the optical cavities configuration are analyzed and the luminosity calculated. As illustrated, the four-mirror two- or three-dimensional scheme is the most appropriate for Compton sources.

Micro-Mechanical Voltage Tunable Fabry-Perot Filters Formed in (111) Silicon. Degree awarded by Colorado Univ., Boulder, CO

Science.gov (United States)

Patterson, James D.

1997-01-01

The MEMS (Micro-Electro-Mechanical-Systems) technology is quickly evolving as a viable means to combine micro-mechanical and micro-optical elements on the same chip. One MEMS technology that has recently gained attention by the research community is the micro-mechanical Fabry-Perot optical filter. A MEMS based Fabry-Perot consists of a vertically integrated structure composed of two mirrors separated by an air gap. Wavelength tuning is achieved by applying a bias between the two mirrors resulting in an attractive electrostatic force which pulls the mirrors closer. In this work, we present a new micro-mechanical Fabry-Perot structure which is simple to fabricate and is integratable with low cost silicon photodetectors and transistors. The structure consists of a movable gold coated oxide cantilever for the top mirror and a stationary Au/Ni plated silicon bottom mirror. The fabrication process is single mask level, self aligned, and requires only one grown or deposited layer. Undercutting of the oxide cantilever is carried out by a combination of RIE and anisotropic KOH etching of the (111) silicon substrate. Metallization of the mirrors is provided by thermal evaporation and electroplating. The optical and electrical characteristics of the fabricated devices were studied and show promissing results. A wavelength shift of 120nm with 53V applied bias was demonstrated by one device geometry using 6.27 micrometer air gap. The finesse of the structure was 2.4. Modulation bandwidths ranging from 91KHz to greater than 920KHz were also observed. Theoretical calculations show that if mirror reflectivity, smoothness, and parallelism are improved, a finesse of 30 is attainable. The predictions also suggest that a reduction of the air gap to 1 micrometer results in an increased wavelength tuning range of 175 nm with a CMOS compatible 4.75V.

Neutral wind measurements by Fabry-Perot interferometry in Antarctica

International Nuclear Information System (INIS)

Stewart, K.D.; Dudeney, J.R.; Rodger, A.S.; Smith, R.W.; Rees, D.

1986-01-01

A large-aperture (150 mm), spatially scanned Fabry-Perot Interferometer (FPI) has been deployed at Halley (75.5 o S, 26.8 o W; L=4.2), Antarctica. Thermospheric neutral wind measurements were made by finding the Doppler shift of the OI( 3 P 2 - 1 D 2 ) 630.0 nm emission. This has allowed the first comparison to be made between southern hemisphere ground-based thermospheric wind measurements and the predictions of a three-dimensional, time-dependent thermospheric global circulation model. Geomagnetic and geographic latitude are well separated at Halley, so we may expect a distinct contrast to the dynamic behaviour observed in the more frequently studied northern polar thermosphere. Although the initial results from the experiment are in general agreement with the model, some consistent and significant differences between the observed wind field and that predicted are evident in the morning sector. These may be related to uncertainties in mapping magnetospheric boundaries to ionospheric heights in the southern hemisphere. The intensity of the 630 nm emission has been examined with respect to the maximum plasma frequency of the Es layer using data from the Advanced Ionospheric Sounder at Halley

Fiber Fabry-Perot interferometer with controllable temperature sensitivity.

Science.gov (United States)

Zhang, Xinpu; Peng, Wei; Zhang, Yang

2015-12-01

We proposed a fiber taper based on the Fabry-Perot (FP) interferometer structure with controllable temperature sensitivity. The FP interferometer is formed by inserting a segment of tapered fiber tip into the capillary and subsequently splicing the other end of the capillary to a single-mode fiber (SMF), the tapered fiber endface, and the spliced face form the FP cavity. Through controlling the inserted tapered fiber length, a series of FP interferometers were made. Because the inserted taper tip has the degree of freedom along the fiber axial, when the FP interferometer is subjected to temperature variation, the thermal expansion of the fiber taper tip will resist the FP cavity length change caused by the evolution of capillary length, and we can control the temperature sensitivity by adjusting the inserted taper length. In this structure, the equivalent thermal expansion coefficient of the FP interferometer can be defined; it was used to evaluate the temperature sensitivity of the FP interferometer, which provides an effective method to eliminate the temperature effect and to enhance other measurement accuracy. We fabricated the FP interferometers and calibrated their temperature characters by measuring the wavelength shift of the resonance dips in the reflection spectrum. In a temperature range of 50°C to 150°C, the corresponding temperature sensitivities can be controlled between 0 and 1.97 pm/°C when the inserted taper is between 75 and 160 μm. Because of its controllable temperature sensitivity, ease of fabrication, and low cost, this FP interferometer can meet different temperature sensitivity requirements in various application areas, especially in the fields which need temperature insensitivity.

Fabry-Perot interferometer measurements of neutral winds and F2 layer variations at the magnetic equator

Directory of Open Access Journals (Sweden)

P. Vila

1998-06-01

Full Text Available This letter presents some night-time observations of neutral wind variations at F2 layer levels near the dip equator, measured by the Fabry-Perot interferometer set up in 1994 at Korhogo (Ivory Coast, geographic latitude 9.25°N, longitude 355°E, dip latitude –2.5°. Our instrument uses the 630 nm (O1D line to determine radial Doppler velocities of the oxygen atoms between 200 and 400 km altitude. First results for November 1994 to March 1995 reveal persistent eastward flows, and frequent intervals of southward winds of larger than 50 ms–1 velocity. Compared with the simultaneous ionospheric patterns deduced from the three West African equatorial ionosondes at Korhogo, Ouagadougou (Burkina-Faso, dip latitude +1.5° and Dakar (Sénégal, dip latitude +5°, they illustrate various impacts of the thermospheric winds on F2 layer density: (1 on the mesoscale evolution (a few 103 km and a few 100 minutes scales and (2 on local fluctuations (hundreds of km and tens of minutes characteristic times. We report on these fluctuations and discuss the opportunity to improve the time-resolution of the Fabry-Perot interferometer at Korhogo.Key words. Ionosphere (Equatorial ionosphere; Ionosphere-atmosphere interaction · Meteorology and Atmospheric Dynamics (General circulation

Dual-wavelength erbium-doped fiber laser with asymmetric fiber Bragg grating Fabry-Perot cavity

Science.gov (United States)

Chen, Cong; Xu, Zhi-wei; Wang, Meng; Chen, Hai-yan

2014-11-01

A novel dual-wavelength fiber laser with asymmetric fiber Bragg grating (FBG) Fabry-Perot (FP) cavity is proposed and experimentally demonstrated. A couple of uniform FBGs are used as the cavity mirrors, and the third FBG is used as intracavity wavelength selector by changing its operation temperature. Experimental results show that by adjusting the operation temperature of the intracavity wavelength selector, a tunable dual-wavelength laser emission can be achieved. The results demonstrate the new concept of dual-wavelength lasing with asymmetric FBG FP resonator and its technical feasibility.

Performance of a 1200 m long suspended Fabry-Perot cavity

CERN Document Server

Freise, A; Gossler, S; Grote, H; Heinzel, G; Lück, H B; Robertson, D I; Strain, K A; Ward, H; Willke, B; Hough, J; Danzmann, K

2002-01-01

Using one arm of the Michelson interferometer and the power recycling mirror of the interferometric gravitational wave detector GEO 600, we created a Fabry-Perot cavity with a length of 1200 m. The main purpose of this experiment was to gather first experience with the main optics, its suspensions and the corresponding control systems. The residual displacement of a main mirror is about 150 nm rms. By stabilizing the length of the 1200 m long cavity to the pre-stabilized laser beam, we achieved an error point frequency noise of 100 mu Hz Hz sup - sup 1 sup / sup 2 at 100 Hz Fourier frequency. In addition we demonstrated the reliable performance of all included subsystems by several 10-hour-periods of continuous stable operation. Thus the full frequency stabilization scheme for GEO 600 was successfully tested.

Effects of the time delays in a non linear pendular Fabry-Perot

International Nuclear Information System (INIS)

Tourrenc, P.; Deruelle, N.

1985-01-01

We study a one arm pendular Fabry-Perot interferometer with specifications corresponding to the two arms interferometers designed to detect gravitational radiation. We consider the non linearities originating from the radiation force and the effects of time delays due to the finite length of the arm. We derive the exact and the associated ''predictivised'' equations for the motion of the suspended mirror. We show that effects of time delays increase considerably the stability of the device when the optical relaxation time is of the order of the period of the pendulum, a case of relevance when light is recycled. However the thermal noise does not seem to be much modified when calculated within a simple approximation scheme

Microbubble-based fiber-optic Fabry-Perot pressure sensor for high-temperature application.

Science.gov (United States)

Li, Zhe; Jia, Pinggang; Fang, Guocheng; Liang, Hao; Liang, Ting; Liu, Wenyi; Xiong, Jijun

2018-03-10

Using arc discharge technology, we fabricated a fiber-optic Fabry-Perot (FP) pressure sensor with a very low temperature coefficient based on a microbubble that can be applied in a high-temperature environment. The thin-walled microbubble can be fabricated by heating the gas-pressurized hollow silica tube (HST) using a commercial fusion splicer. Then, the well-cut single-mode fiber (SMF) was inserted into the microbubble, and they were fused together. Thus, the FP cavity can be formed between the end of the SMF and the inner surface of the microbubble. The diameter of the microbubble can be up to 360 μm with the thickness of the wall being approximately 0.5 μm. Experimental results show that such a sensor has a linear sensitivity of approximately -6.382  nm/MPa, -5.912  nm/MPa at 20°C, and 600°C within the pressure range of 1 MPa. Due to the thermal expansion coefficient of the SMF being slightly larger than that of silica, we can fuse the SMF and the HST with different lengths; thus, the sensor has a very low temperature coefficient of approximately 0.17 pm/°C.

Modeling of absorption data complicated by Fabry endash Perot interference in germanosilicate thin-film waveguides

International Nuclear Information System (INIS)

Simmons-Potter, K.; Simmons, J.H.

1996-01-01

Complex absorption spectra obtained from thin films at normal incidence can be difficult to interpret owing to the appearance of Fabry endash Perot interference fringes in the data. We describe a technique for modeling such spectra so that true absorption features can be identified and evaluated separately from the overlying fringes. The technique is used to interpret data obtained from photosensitive germanosilicate solgel films on fused-silica substrates but may be easily extended to analysis in other material systems. copyright 1996 Optical Society of America

Feedback stabilized tandem Fabry-Perot interferometer

International Nuclear Information System (INIS)

Fukushima, Hiroyuki; Ito, Mikio; Shirasu, Hiroshi.

1986-01-01

A new system for measuring the isotopic ratio of uranium, in which two plane-type Fabry-Perot interferometers (tandem FP) are connected in series. The parallelism between the two FPs is achieved automatically by a feedback control mechanism based on laser interference fringe monitoring. The structure of the tandem FP, feedback control system, automatic parallelism adjustment mechanism and wavelength synchronization mechanism are described in detail. For experiments, a hollow cathode discharge tube of a pulse discharge type is employed. Measurements are made to determine the effects of pulse width on the 238 U peak height of 502.7 nm line, recorder traces of 235 U and 238 U lines, half width for 238 U component of the 502.7 nm line, SN ratio, reproducibility of the 235 U/ 238 U peak height ratio and 235 U/ 238 U intensity ratio. Considerations are made on the spectral line width, contrast, transmission factor, and stability of automatic parallelism control and wavelength synchronization. Results obtained indicates that a single-type interferometer would serve adequately for measuring the 235 U/ 238 U ratio if the automatic parallelism control developed here is used. The ultimate object of the tandem system is to make measurement of 236 U. Satisfactory results have not obtained as yet, but most likely the present system would make it possible if a light source of a higher intensity and advanced photometric techniques are developed. (Nogami, K.)

A highly directive graphene antenna embedded inside a Fabry-Perot cavity in terahertz regime

Science.gov (United States)

Roshanaei, Majid; Karami, Hamidreza; Dehkhoda, Parisa; Esfahani, Hamid; Dabir, Fatemeh

2018-05-01

In this paper, a highly directive nano-thickness graphene-based antenna is introduced in the terahertz frequency band. The antenna is a graphene patch dipole which is placed between two Bragg mirrors called Fabry-Perot cavity. Tunability of the graphene's conductivity makes it possible to excite the desired resonances of the cavity. Here, first, a single resonant antenna is introduced at 5 THz with an enhanced gain from 2.11 dBi to 12.8 dBi with a beamwidth of 22.7°. Then, a triple resonant antenna at 4.7, 5 and 5.3 THz is presented with respective gains of 7.97, 11.9 and 8.52 dBi. Finally, the effect of dimensions and number of the dielectric layers of the cavity are studied in order to further increase in directivity.

Readout of micromechanical cantilever sensor arrays by Fabry-Perot interferometry

International Nuclear Information System (INIS)

Wehrmeister, Jana; Fuss, Achim; Saurenbach, Frank; Berger, Ruediger; Helm, Mark

2007-01-01

The increasing use of micromechanical cantilevers in sensing applications causes a need for reliable readout techniques of micromechanical cantilever sensor (MCS) bending. Current optical beam deflection techniques suffer from drawbacks such as artifacts due to changes in the refraction index upon exchange of media. Here, an adaptation of the Fabry-Perot interferometer is presented that allows simultaneous determination of MCS bending and changes in the refraction index of media. Calibration of the instrument with liquids of known refraction index provides an avenue to direct measurement of bending with nanometer precision. Versatile construction of flow cells in combination with alignment features for substrate chips allows simultaneous measurement of two MCS situated either on the same, or on two different support chips. The performance of the instrument is demonstrate in several sensing applications, including adsorption experiments of alkanethioles on MCS gold surfaces, and measurement of humidity changes in air

Time-domain multiplexed high resolution fiber optics strain sensor system based on temporal response of fiber Fabry-Perot interferometers.

Science.gov (United States)

Chen, Jiageng; Liu, Qingwen; He, Zuyuan

2017-09-04

We developed a multiplexed strain sensor system with high resolution using fiber Fabry-Perot interferometers (FFPI) as sensing elements. The temporal responses of the FFPIs excited by rectangular laser pulses are used to obtain the strain applied on each FFPI. The FFPIs are connected by cascaded couplers and delay fiber rolls for the time-domain multiplexing. A compact optoelectronic system performing closed-loop cyclic interrogation is employed to improve the sensing resolution and the frequency response. In the demonstration experiment, 3-channel strain sensing with resolutions better than 0.1 nε and frequency response higher than 100 Hz is realized.

Strain and high-temperature discrimination using a Type II fiber Bragg grating and a miniature fiber Fabry-Perot interferometer.

Science.gov (United States)

Jiang, Yajun; Yang, Dexing; Yuan, Yuan; Xu, Jian; Li, Dong; Zhao, Jianlin

2016-08-10

A novel method for simultaneous measurement of strain and high temperature using a Type II fiber Bragg grating (FBG) and a miniature fiber Fabry-Perot interferometer (MFFPI) is proposed. The MFFPI is produced by fusion splicing a short section of quartz capillary tube with two single-mode fibers, and then it is exposed by a focused femtosecond laser and a phase mask to inscribe a Type II FBG nearby. The reflection spectrum of this sensor is the superposition of the reflection spectrum of the FBG and the interference fringe of the MFFPI. This sensor shows perfect high-temperature and strain responses. Because of the different responses to the uniform variations of strain and temperature, by measuring the reflection peak of FBG and one of the interference dips of the MFFPI, strain and temperature can be simultaneously determined. The resolutions of this particular sensor in measuring strain and temperature are estimated to be ±8.4  μϵ and ±3.3°C, respectively, in the range from 0 to 1122 μϵ and from 23°C to 600°C.

Picometre displacement measurements using a differential Fabry-Perot optical interferometer and an x-ray interferometer

Science.gov (United States)

Çelik, Mehmet; Hamid, Ramiz; Kuetgens, Ulrich; Yacoot, Andrew

2012-08-01

X-ray interferometry is emerging as an important tool for dimensional nanometrology both for sub-nanometre measurement and displacement. It has been used to verify the performance of the next generation of displacement measuring optical interferometers within the European Metrology Research Programme project NANOTRACE. Within this project a more detailed set of comparison measurements between the x-ray interferometer and a dual channel Fabry-Perot optical interferometer (DFPI) have been made to demonstrate the capabilities of both instruments for picometre displacement metrology. The results show good agreement between the two instruments, although some minor differences of less than 5 pm have been observed.

Extrinsic optical-fiber ultrasound sensor using a thin polymer film as a low-finesse Fabry-Perot interferometer

Science.gov (United States)

Beard, P. C.; Mills, T. N.

1996-02-01

Theoretical and experimental aspects of an extrinsic optical-fiber ultrasound sensor are described. The sensor is based on a thin transparent polymer film acting as a low-finesse Fabry-Perot cavity that is mounted at the end of a multimode optical fiber. Performance was found to be comparable with that of a piezoelectric polyvinylidene difluoride-membrane (PVDF) hydrophone with a sensitivity of 61 mV/MPa, an acoustic noise floor of 2.3 KPa over a 25-MHz bandwidth, and a frequency response to 25 MHz. The wideband-sensitive response and design flexibility of the concept suggests that it may find application as an alternative to piezoelectric devices for the detection and measurement of ultrasound.

Fabry-Perot interferometry using an image-intensified rotating-mirror streak camera

International Nuclear Information System (INIS)

Seitz, W.L.; Stacy, H.L.

1983-01-01

A Fabry-Perot velocity interferometer system is described that uses a modified rotating mirror streak camera to recrod the dynamic fringe positions. A Los Alamos Model 72B rotating-mirror streak camera, equipped with a beryllium mirror, was modified to include a high aperture (f/2.5) relay lens and a 40-mm image-intensifier tube such that the image normally formed at the film plane of the streak camera is projected onto the intensifier tube. Fringe records for thin (0.13 mm) flyers driven by a small bridgewire detonator obtained with a Model C1155-01 Hamamatsu and Model 790 Imacon electronic streak cameras are compared with those obtained with the image-intensified rotating-mirror streak camera (I 2 RMC). Resolution comparisons indicate that the I 2 RMC gives better time resolution than either the Hamamatsu or the Imacon for total writing times of a few microseconds or longer

Advanced Interrogation of Fiber-Optic Bragg Grating and Fabry-Perot Sensors with KLT Analysis

Science.gov (United States)

Tosi, Daniele

2015-01-01

The Karhunen-Loeve Transform (KLT) is applied to accurate detection of optical fiber sensors in the spectral domain. By processing an optical spectrum, although coarsely sampled, through the KLT, and subsequently processing the obtained eigenvalues, it is possible to decode a plurality of optical sensor results. The KLT returns higher accuracy than other demodulation techniques, despite coarse sampling, and exhibits higher resilience to noise. Three case studies of KLT-based processing are presented, representing most of the current challenges in optical fiber sensing: (1) demodulation of individual sensors, such as Fiber Bragg Gratings (FBGs) and Fabry-Perot Interferometers (FPIs); (2) demodulation of dual (FBG/FPI) sensors; (3) application of reverse KLT to isolate different sensors operating on the same spectrum. A simulative outline is provided to demonstrate the KLT operation and estimate performance; a brief experimental section is also provided to validate accurate FBG and FPI decoding. PMID:26528975

GHGSat-D: Greenhouse gas plume imaging and quantification from space using a Fabry-Perot imaging spectrometer

Science.gov (United States)

McKeever, J.; Durak, B. O. A.; Gains, D.; Jervis, D.; Varon, D. J.; Germain, S.; Sloan, J. J.

2017-12-01

GHGSat, Inc. has launched the first satellite designed to detect and quantify greenhouse gas emissions from individual industrial sites. Our demonstration satellite GHGSat-D or "CLAIRE" was launched in June 2016. It weighs less than 15 kg and its primary instrument is a miniaturized Fabry-Perot imaging spectrometer with spectral resolution on the order of 0.1 nm. The spectral bandpass is 1635-1670 nm, giving the instrument access to absorption bands of both CO2 and CH4. Our system is based on targeted observations rather than global coverage, and our spatial imaging resolution is a key differentiator. Specifically, with a ground sampling distance of effect of the Fabry-Perot resonator and the scrolling scene gives a different spectral sampling of each surface location in every image. While our data processing toolchain does not produce a conventional hyperspectral dataset, it does yield a spectral decomposition of the spatially resolved signal that is compared to a model that includes atmospheric radiative transfer and the instrument's pixel-dependent spectral responsivity. Our presentation will describe the instrument design, concept of operations and retrievals approach. We will also present images and results from GHGSat-D at different processing levels, including high-resolution column density retrievals. An observation of the degassing flux of methane from the outlet of a recently impounded hydroelectric reservoir will be shown as an example. Finally we discuss some performance limitations of GHGSat-D and our plans to overcome them as we update the instrument design for the next satellites.

Fabry-Perot Interferometry in the Integer and Fractional Quantum Hall Regimes

Science.gov (United States)

McClure, Douglas; Chang, Willy; Kou, Angela; Marcus, Charles; Pfeiffer, Loren; West, Ken

2011-03-01

We present measurements of electronic Fabry-Perot interferometers in the integer and fractional quantum Hall regimes. Two classes of resistance oscillations may be seen as a function of magnetic field and gate voltage, as we have previously reported. In small interferometers in the integer regime, oscillations of the type associated with Coulomb interaction are ubiquitous, while those consistent with single-particle Aharonov-Bohm interference are seen to co-exist in some configurations. The amplitude scaling of both types with temperature and device size is consistent with a theoretical model. Oscillations are further observed in the fractional quantum Hall regime. Here the dependence of the period on the filling factors in the constrictions and bulk of the interferometer can shed light on the effective charge of the interfering quasiparticles, but care is needed to distinguish these oscillations from those associated with integer quantum Hall states. We acknowledge funding from Microsoft Project Q and IBM.

Development of Silicon-substrate Based Fabry-Perot Etalons for far-IR Astrophysics

Science.gov (United States)

Stacey, Gordon

We propose to design, construct and test silicon-substrate-based (SSB) mirrors necessary for high performance Fabry-Perot interferometers (FPIs) to be used in the 25-40 um mid-IR band. These mirrors will be fabricated from silicon wafers that are anti-reflection coated (ARC) by micromachining an artificial dielectric meta-material on one side, and depositing optimized gold-metalized patterns on the other. Two mirrors with the metalized surfaces facing one-another form the Fabry-Perot cavity, also known as the FPI etalon. The exterior surfaces of the silicon mirrors are anti-reflection coated for both good transmission in the science band, and to prevent unwanted parasitic FPI cavities from forming between the four surfaces (one anti-reflection coated, one metalized for each mirror) of the FPI etalon. The mirrors will be tested within a Miniature Cryogenic Scanning Fabry-Perot (MCSF) that we have designed through support of a previous NASA grant (NNX09AB95G). This design is based on our long experience in constructing and using scanning FPI in the mid-IR to submm range, and fits within test-beds we have on hand that are suitable for both warm and cold tests. The key technologies are the ARC and tuned mirrors that are enabled by silicon nano-machining techniques. The creation of these SSB mirrors promises greatly improved performance over previous versions of mid-IR to submm-band FPIs that are based on mirrors made from free-standing metal mesh stretched over support rings. Performance is improved both structurally and in terms of sensitivity, and is measured as the product of the cavity finesse times transmission. Our electromagnetic modeling suggests that SSB mirrors will improve this product by a factor of 2 over the best free standing mesh etalons available. This translates into a factor of sqrt(2) improvement in sensitivity per etalon, or a full factor of 2 when used in a tandem (dual etalon) FPI spectrometer. The SSB improvements are due to both the stiff (~ 0

A Fabry-Perot interferometer for hard X-rays

International Nuclear Information System (INIS)

Caticha, A.; Caticha-Ellis, S.

1990-01-01

Reflection and transmission coefficients are calculated of a sequence of N thin parallel crystals diffracting close to normal incidence and separated by thin non-diffracting gaps. From the study of the particular case N=2 a new Fabry-Perot interferometer (FPI) is proposed for hard X-rays (wavelengths of the order of Angstroms). It is found that the FPI plates do not need to be carved from a single perfect crystal block but may be grown or cleaved by other methods. This interesting possibility is suggested by two facts. First, it is known that for incidence close to normal various features of dynamical diffraction are much less sensitive to crystal defects and crystal orientation. Second, the existence of a mismatch between the lattices of the two FPI plates may affect but does not qualitatively alter the performance of the FPI. It is shown that the optimal thickness of the plates is of the order of a few microns or less. The plates may be built from a wide variety of materials. The transmission of X-rays is studied as a function of the energy and direction of the incident photons for various values of the plate thickness, of the gap, of the lattice mismatch, and also for different materials in the gap. The transmission profile exhibits a peak which is spectrally very sharp (about 10 -3 eV for low order reflections and even less for higher ones) and which can be easily tuned by changing either the lattice mismatch or the temperature. FPI plates built of materials with low absorption such as graphite seem to be particularly convenient. Several possible applications are suggested. (author)

Cascaded-cavity Fabry-Perot interferometer for simultaneous measurement of temperature and strain with cross-sensitivity compensation

Science.gov (United States)

Tian, Jiajun; Jiao, Yuzhu; Ji, Shaobo; Dong, Xiaolong; Yao, Yong

2018-04-01

We propose and demonstrate a fiber sensor for simultaneous temperature and strain measurements. The proposed sensor is implemented by a cascaded-cavity Fabry-Perot (FP) fiber interferometer. The two cascaded FP cavities comprise a micro-air-cavity in a hollow-core tube fiber and a micro-silica-cavity in a standard single-mode fiber. To separate the interference spectrum of each FP cavity, the total spectrum is filtered in the frequency domain through band-pass filters, whose central frequencies were predesigned based on the relationship between the spatial frequency and free spectral range of each FP cavity. The different cross-sectional areas and thermal-optic coefficients of the two FP cavities confer different sensitivities to temperature and strain. Both parameters were measured simultaneously by tracking the wavelength shifts in the filtered interference spectra of the FP cavities. Moreover, the temperature-strain cross-sensitivity was compensated by solving a sensitivity-coefficient matrix equation for the two cavities, using the calibrated temperatures and strains. Other advantages of the proposed sensor are simple fabrication and an all-fiber structure. Owing to these properties, the proposed sensor is potentially applicable to real sensing applications.

Optical-cell model based on the lasing competition of mode structures with different Q-factors in high-power semiconductor lasers

Energy Technology Data Exchange (ETDEWEB)

Podoskin, A. A., E-mail: podoskin@mail.ioffe.ru; Shashkin, I. S.; Slipchenko, S. O.; Pikhtin, N. A.; Tarasov, I. S. [Russian Academy of Sciences, Ioffe Institute (Russian Federation)

2015-08-15

A model describing the operation of a completely optical cell, based on the competition of lasing of Fabry-Perot cavity modes and the high-Q closed mode in high-power semiconductor lasers is proposed. Based on rate equations, the conditions of lasing switching between Fabry-Perot modes for ground and excited lasing levels and the closed mode are considered in the case of increasing internal optical loss under conditions of high current pump levels. The optical-cell operation conditions in the mode of a high-power laser radiation switch (reversible mode-structure switching) and in the mode of a memory cell with bistable irreversible lasing switching between mode structures with various Q-factors are considered.

Development of a Fabry-Perot cavity for the Compton polarimetry

International Nuclear Information System (INIS)

Jorda, Jean-Paul

1997-01-01

A quick, precise and non-destructive longitudinal polarisation measurement should be a great advantage for the HAPPEX experiment at CEBAF (Jefferson Lab, USA). To achieve this, it could be possible to use a Fabry-Perot cavity to get a high photon flux at the electron-photon interaction point of a Compton polarimeter. This thesis is a first study for the design of such a system. We have shown that a 'monolithic' cavity, i.e. with mirrors mounted on fixed stage, is a good solution. My contribution for these studies is the development of a code to compute the optimum geometry of a cavity. Another of my contribution concerns the test of a cavity based on commercial mirrors with a gain > 160, using the Pound-Drever method to lock the laser frequency. My studies concern optical matching between the laser beam and the cavity, the choice of the frequency of modulation for the feed-back system and the characterization of the intracavity power. This work is a first step of the studies which will lead to the integration of a cavity based system on the CEBAF beam line. (author) [fr

Displacement-noise-free gravitational-wave detection with a single Fabry-Perot cavity: A toy model

International Nuclear Information System (INIS)

Tarabrin, Sergey P.; Vyatchanin, Sergey P.

2008-01-01

We propose a detuned Fabry-Perot cavity, pumped through both the mirrors, as a toy model of the gravitational-wave (GW) detector partially free from displacement noise of the test masses. It is demonstrated that the noise of cavity mirrors can be eliminated, but the one of lasers and detectors cannot. The isolation of the GW signal from displacement noise of the mirrors is achieved in a proper linear combination of the cavity output signals. The construction of such a linear combination is possible due to the difference between the reflected and transmitted output signals of detuned cavity. We demonstrate that in low-frequency region the obtained displacement-noise-free response signal is much stronger than the f gw 3 -limited sensitivity of displacement-noise-free interferometers recently proposed by S. Kawamura and Y. Chen. However, the loss of the resonant gain in the noise cancelation procedure results is the sensitivity limitation of our toy model by displacement noise of lasers and detectors

A new detection method used to calibrate Fabry-Perot interferometers in the infrared range

International Nuclear Information System (INIS)

Talvard, M.; Javon, C.; Garcin, M.; Thouvenin, D.

1993-06-01

Fabry-Perot interferometers are routinely used in the Tore Supra Tokamak in order to measure the time evolution of the electron temperature of the confined plasmas. Calibration of such interferometers requires the detection of very low DC levels (0.1 nV) with signal-to-noise ratios less than 10 -5 , which is generally not compatible with standard detection methods. A new correlation method to achieve this absolute calibration is proposed. It is based on a proper noise auto-correlation technique combined with an optimized signal filtering involving Fourier analysis. The advantages of the method are detailed and experimentally compared to standard averaging techniques, such as coherent addition and synchronous detection. The method can be used in a more general context every time very small amplitude signals are to be measured

General Method for Calculating the Response and Noise Spectra of Active Fabry-Perot Semiconductor Waveguides With External Optical Injection

DEFF Research Database (Denmark)

Blaaberg, Søren; Mørk, Jesper

2009-01-01

We present a theoretical method for calculating small-signal modulation responses and noise spectra of active Fabry-Perot semiconductor waveguides with external light injection. Small-signal responses due to either a modulation of the pump current or due to an optical amplitude or phase modulatio...... amplifiers and an injection-locked laser. We also demonstrate the applicability of the method to analyze slow and fast light effects in semiconductor waveguides. Finite reflectivities of the facets are found to influence the phase changes of the injected microwave-modulated light....

Designing, Probing, and Stabilizing Exotic Fabry-Perot Cavities for Studying Strongly Correlated Light

Science.gov (United States)

Ryou, Albert

Synthetic materials made of engineered quasiparticles are a powerful platform for studying manybody physics and strongly correlated systems due to their bottom-up approach to Hamiltonian modeling. Photonic quasiparticles called polaritons are particularly appealing since they inherit fast dynamics from light and strong interaction from matter. This thesis describes the experimental demonstration of cavity Rydberg polaritons, which are composite particles arising from the hybridization of an optical cavity with Rydberg EIT, as well as the tools for probing and stabilizing the cavity. We first describe the design, construction, and testing of a four-mirror Fabry-Perot cavity, whose small waist size on the order of 10 microns is comparable to the Rydberg blockade radius. By achieving strong coupling between the cavity photon and an atomic ensemble undergoing electromagnetically induced transparency (EIT), we observe the emergence of the dark-state polariton and characterize its single-body properties as well as the single-quantum nonlinearity. We then describe the implementation of a holographic spatial light modulator for exciting different transverse modes of the cavity, an essential tool for studying polariton-polariton scattering. For compensating optical aberrations, we employ a digital micromirror device (DMD), combining beam shaping with adaptive optics to produce diffraction-limited light. We quantitatively measure the purity of the DMD-produced Hermite-Gauss modes and confirm up to 99.2% efficiency. One application of the technique is to create Laguerre-Gauss modes, which have been used to probe synthetic Landau levels for photons in a twisted, nonplanar cavity. Finally, we describe the implementation of an FPGA-based FIR filter for stabilizing the cavity. We digitally cancel the acoustical resonances of the feedback-controlled mechanical system, thereby demonstrating an order-of-magnitude enhancement in the feedback bandwidth from 200 Hz to more than 2 k

Photonic filtering of microwave signals in the frequency range of 0.01-20 GHz using a Fabry-Perot filter

Energy Technology Data Exchange (ETDEWEB)

Aguayo-Rodriguez, G; Zaldivar-Huerta, I E [Instituto Nacional de Astrofisica, Optica y Electronica (INAOE). Sta. Maria Tonantzintla, Pue. Mexico (Mexico); GarcIa-Juarez, A [Depto. de Investigacion en Fisica, Universidad de Sonora (UNISON) Hermosillo, Son. Mexico (Mexico); Rodriguez-Asomoza, J [Depto. de Ingenieria Electronica, Universidad de las Americas-Puebla (UDLA). San Andres Cholula, Pue. Mexico (Mexico); Larger, L; Courjal, N [Laboratoire d' Optique P. M. Duffieux, UMR 6603 CNRS, Institut des Microtechiques de Franche-Comte, FRW 0067, UFR Sciences et Techniques, Universite de Franche-Comte (UFC), Besancon cedex (France)

2011-01-01

We demonstrate experimentally the efficiency of tuning of a photonic filter in the frequency range of 0.01 to 20 GHz. The presented work combines the use of a multimode optical source associated with a dispersive optical fiber to obtain the filtering effect. Tunability effect is achieved by the use of a Fabry-Perot filter that allows altering the spectral characteristics of the optical source. Experimental results are validated by means of numerical simulations. The scheme here proposed has a potential application in the field of optical telecommunications.

Discrete mode lasers for communications applications

Science.gov (United States)

Barry, L. P.; Herbert, C.; Jones, D.; Kaszubowska-Anandarajah, A.; Kelly, B.; O'Carroll, J.; Phelan, R.; Anandarajah, P.; Shi, K.; O'Gorman, J.

2009-02-01

The wavelength spectra of ridge waveguide Fabry Perot lasers can be modified by perturbing the effective refractive index of the guided mode along very small sections of the laser cavity. One way of locally perturbing the effective index of the lasing mode is by etching features into the ridge waveguide such that each feature has a small overlap with the transverse field profile of the unperturbed mode, consequently most of the light in the laser cavity is unaffected by these perturbations. A proportion of the propagating light is however reflected at the boundaries between the perturbed and the unperturbed sections. Suitable positioning of these interfaces allows the mirror loss spectrum of a Fabry Perot laser to be manipulated. In order to achieve single longitudinal mode emission, the mirror loss of a specified mode must be reduced below that of the other cavity modes. Here we review the latest results obtained from devices containing such features. These results clearly demonstrate that these devices exceed the specifications required for a number of FTTH and Datacomms applications, such as GEPON, LX4 and CWDM. As well as this we will also present initial results on the linewidth of these devices.

Parallelised photoacoustic signal acquisition using a Fabry-Perot sensor and a camera-based interrogation scheme

Science.gov (United States)

Saeb Gilani, T.; Villringer, C.; Zhang, E.; Gundlach, H.; Buchmann, J.; Schrader, S.; Laufer, J.

2018-02-01

Tomographic photoacoustic (PA) images acquired using a Fabry-Perot (FP) based scanner offer high resolution and image fidelity but can result in long acquisition times due to the need for raster scanning. To reduce the acquisition times, a parallelised camera-based PA signal detection scheme is developed. The scheme is based on using a sCMOScamera and FPI sensors with high homogeneity of optical thickness. PA signals were acquired using the camera-based setup and the signal to noise ratio (SNR) was measured. A comparison of the SNR of PA signal detected using 1) a photodiode in a conventional raster scanning detection scheme and 2) a sCMOS camera in parallelised detection scheme is made. The results show that the parallelised interrogation scheme has the potential to provide high speed PA imaging.

MEMS fiber-optic Fabry-Perot pressure sensor for high temperature application

Science.gov (United States)

Fang, G. C.; Jia, P. G.; Cao, Q.; Xiong, J. J.

2016-10-01

We design and demonstrate a fiber-optic Fabry-Perot pressure sensor (FOFPPS) for high-temperature sensing by employing micro-electro-mechanical system (MEMS) technology. The FOFPPS is fabricated by anodically bonding the silicon wafer and the Pyrex glass together and fixing the facet of the optical fiber in parallel with the silicon surface by glass frit and organic adhesive. The silicon wafer can be reduced through dry etching technology to construct the sensitive diaphragm. The length of the cavity changes with the deformation of the diaphragm due to the loaded pressure, which leads to a wavelength shift of the interference spectrum. The pressure can be gauged by measuring the wavelength shift. The pressure experimental results show that the sensor has linear pressure sensitivities ranging from 0 kPa to 600 kPa at temperature range between 20°C to 300°C. The pressure sensitivity at 300°C is approximately 27.63 pm/kPa. The pressure sensitivities gradually decrease with increasing the temperature. The sensor also has a linear thermal drift when temperature changes from 20°C - 300°C.

Polar cap mesosphere wind observations: comparisons of simultaneous measurements with a Fabry-Perot interferometer and a field-widened Michelson interferometer.

Science.gov (United States)

Fisher, G M; Killeen, T L; Wu, Q; Reeves, J M; Hays, P B; Gault, W A; Brown, S; Shepherd, G G

2000-08-20

Polar cap mesospheric winds observed with a Fabry-Perot interferometer with a circle-to-line interferometer optical (FPI/CLIO) system have been compared with measurements from a field-widened Michelson interferometer optimized for E-region winds (ERWIN). Both instruments observed the Meinel OH emission emanating from the mesopause region (approximately 86 km) at Resolute Bay, Canada (74.9 degrees N, 94.9 degrees W). This is the first time, to our knowledge, that winds measured simultaneously from a ground-based Fabry-Perot interferometer and a ground-based Michelson interferometer have been compared at the same location. The FPI/CLIO and ERWIN instruments both have a capability for high temporal resolution (less than 10 min for a full scan in the four cardinal directions and the zenith). Statistical comparisons of hourly mean winds for both instruments by scatterplots show excellent agreement, indicating that the two optical techniques provide equivalent observations of mesopause winds. Small deviations in the measured wind can be ascribed to the different zenith angles used by the two instruments. The combined measurements illustrate the dominance of the 12-h wave in the mesopause winds at Resolute Bay, with additional evidence for strong gravity wave activity with much shorter periods (tens of minutes). Future operations of the two instruments will focus on observation of complementary emissions, providing a unique passive optical capability for the determination of neutral winds in the geomagnetic polar cap at various altitudes near the mesopause.

Nonlinear estimation of ring-down time for a Fabry-Perot optical cavity.

Science.gov (United States)

Kallapur, Abhijit G; Boyson, Toby K; Petersen, Ian R; Harb, Charles C

2011-03-28

This paper discusses the application of a discrete-time extended Kalman filter (EKF) to the problem of estimating the decay time constant for a Fabry-Perot optical cavity for cavity ring-down spectroscopy (CRDS). The data for the estimation process is obtained from a CRDS experimental setup in terms of the light intensity at the output of the cavity. The cavity is held in lock with the input laser frequency by controlling the distance between the mirrors within the cavity by means of a proportional-integral (PI) controller. The cavity is purged with nitrogen and placed under vacuum before chopping the incident light at 25 KHz and recording the light intensity at its output. In spite of beginning the EKF estimation process with uncertainties in the initial value for the decay time constant, its estimates converge well within a small neighborhood of the expected value for the decay time constant of the cavity within a few ring-down cycles. Also, the EKF estimation results for the decay time constant are compared to those obtained using the Levenberg-Marquardt estimation scheme.

Initial daytime and nighttime SOFDI observations of thermospheric winds from Fabry-Perot Doppler shift measurements of the 630-nm OI line-shape profile

Directory of Open Access Journals (Sweden)

A. J. Gerrard

2011-09-01

Full Text Available In this paper we present both night and day thermospheric wind observations made with the Second-generation, Optimized, Fabry-Perot Doppler Imager (SOFDI, a novel triple-etalon Fabry-Perot interferometer (FPI designed to make 24-h measurements of thermospheric winds from OI 630-nm emission. These results were obtained from the northeastern United States and from under the magnetic equator at Huancayo, Peru and demonstrate the current instrument capability for measurements of Doppler shifts for either night or day. We found the uncertainties in the measurements agree with expected values based upon forward modeling calculations; nighttime wind components having an uncertainty of ~20-m s−1 at 30-min resolution and daytime wind components having an uncertainty of ~70-m s−1 at 20-min resolution. The nighttime uncertainties are typically larger than those seen with traditional single-etalon FPIs, which occur at the cost of being able to achieve daytime measurements. The thermospheric wind measurements from Huancayo replicate recently reported CHAMP zonal winds and are in disagreement with current empirical wind climatologies. In addition, we discuss the incorporation of how multiple point heads in the SOFDI instrument will allow for unique studies of gravity wave activity in future measurements.

Development of a six channel Fabry-Perot interferometer for continuous measurement of electron temperature of Tokamak plasma. Application to current diffusion study

International Nuclear Information System (INIS)

Talvard, M.

1984-10-01

It is shown how the properties of the electron cyclotron emission of a tokamak plasma can be used to measure the electron temperature. The design of a six channel Fabry-Perot interferometer is then described. This interferometer allows the measurement of the time evolution of the electron temperature profile of the plasma in the TFR tokamak. Using this technique interesting results have been obtained concerning the current penetration during the start up phase of a tokamak discharge [fr

A Fabry-Perot Interferometry Based MRI-Compatible Miniature Uniaxial Force Sensor for Percutaneous Needle Placement

Science.gov (United States)

Shang, Weijian; Su, Hao; Li, Gang; Furlong, Cosme; Fischer, Gregory S.

2014-01-01

Robot-assisted surgical procedures, taking advantage of the high soft tissue contrast and real-time imaging of magnetic resonance imaging (MRI), are developing rapidly. However, it is crucial to maintain tactile force feedback in MRI-guided needle-based procedures. This paper presents a Fabry-Perot interference (FPI) based system of an MRI-compatible fiber optic sensor which has been integrated into a piezoelectrically actuated robot for prostate cancer biopsy and brachytherapy in 3T MRI scanner. The opto-electronic sensing system design was minimized to fit inside an MRI-compatible robot controller enclosure. A flexure mechanism was designed that integrates the FPI sensor fiber for measuring needle insertion force, and finite element analysis was performed for optimizing the correct force-deformation relationship. The compact, low-cost FPI sensing system was integrated into the robot and calibration was conducted. The root mean square (RMS) error of the calibration among the range of 0–10 Newton was 0.318 Newton comparing to the theoretical model which has been proven sufficient for robot control and teleoperation. PMID:25126153

Wavelength-tunable thulium-doped fiber laser by employing a self-made Fabry-Perot filter

Science.gov (United States)

Wang, Y. P.; Ju, Y. L.; Wu, C. T.; Liu, W.; Yang, C.

2017-06-01

In this demonstration, we proposed a novel wavelength-tunable thulium-doped fiber laser (TDFL) with a self-made Fabry-Perot (F-P) filter. When the F-P filter was not inserted, the maximum output power of 11.1 W was achieved when the pump power was 70.2 W. The corresponding optical-to-optical conversion efficiency was 15.8% and the slope efficiency was 22.1%. When the F-P filter was inserted, the output wavelength could be tuned from 1952.9 to 1934.9 nm with the change of cavity length of F-P filter which was fixed on a piezoelectric ceramic transducer (PZT) controlled by the voltage applied to it. The full width at half maximum (FWHM) was no more than 0.19 nm. Furthermore, the wavelength fluctuations of the tunable fiber laser were kept within  ±0.2 nm.

Tunable and stable single-longitudinal-mode dual-wavelength erbium fiber laser with 1.3 nm mode spacing output

International Nuclear Information System (INIS)

Yeh, C H; Shih, F Y; Wang, C H; Chow, C W; Chi, S

2008-01-01

In this investigation, we propose and investigate a stable and tunable dual-wavelength erbium-doped fiber (EDF) ring laser with self-injected Fabry-Perot laser diode (FP-LD) scheme. By using an FP-LD incorporated with a tunable bandpass filter (TBF) within the gain cavity, the fiber laser can lase at two single-longitudinal-mode (SLM) wavelengths simultaneously due to the self-injected operation. The proposed dual-wavelength laser has a good performance of the output power and optical side-mode suppression ratio (SMSR). The laser also shows a wide tuning range from 1523.08 to 1562.26 nm. Besides, the output stabilities of the fiber laser are also discussed

Combination of highly nonlinear fiber, an optical bandpass filter, and a Fabry-Perot filter to improve the signal-to-noise ratio of a supercontinuum continuous-wave optical source.

Science.gov (United States)

Nan, Yinbo; Huo, Li; Lou, Caiyun

2005-05-20

We present a theoretical study of a supercontinuum (SC) continuous-wave (cw) optical source generation in highly nonlinear fiber and its noise properties through numerical simulations based on the nonlinear Schrödinger equation. Fluctuations of pump pulses generate substructures between the longitudinal modes that result in the generation of white noise and then in degradation of coherence and in a decrease of the modulation depths and the signal-to-noise ratio (SNR). A scheme for improvement of the SNR of a multiwavelength cw optical source based on a SC by use of the combination of a highly nonlinear fiber (HNLF), an optical bandpass filter, and a Fabry-Perot (FP) filter is presented. Numerical simulations show that the improvement in modulation depth is relative to the HNLF's length, the 3-dB bandwidth of the optical bandpass filter, and the reflection ratio of the FP filter and that the average improvement in modulation depth is 13.7 dB under specified conditions.

Entanglement of transverse modes in a pendular cavity

OpenAIRE

Mancini, Stefano; Gatti, Alessandra

2001-01-01

We study the phenomena that arise in the transverse structure of electromagnetic field impinging on a linear Fabry-Perot cavity with an oscillating end mirror. We find quantum correlations among transverse modes which can be considered as a signature of their entanglement.

MEMS Fabry-Perot sensor interrogated by optical system-on-a-chip for simultaneous pressure and temperature sensing.

Science.gov (United States)

Pang, Cheng; Bae, Hyungdae; Gupta, Ashwani; Bryden, Kenneth; Yu, Miao

2013-09-23

We present a micro-electro-mechanical systems (MEMS) based Fabry-Perot (FP) sensor along with an optical system-on-a-chip (SOC) interrogator for simultaneous pressure and temperature sensing. The sensor employs a simple structure with an air-backed silicon membrane cross-axially bonded to a 45° polished optical fiber. This structure renders two cascaded FP cavities, enabling simultaneous pressure and temperature sensing in close proximity along the optical axis. The optical SOC consists of a broadband source, a MEMS FP tunable filter, a photodetector, and the supporting circuitry, serving as a miniature spectrometer for retrieving the two FP cavity lengths. Within the measured pressure and temperature ranges, experimental results demonstrate that the sensor exhibits a good linear response to external pressure and temperature changes.

Ultrafast Fabry-Perot fiber-optic pressure sensors for multimedia blast event measurements.

Science.gov (United States)

Zou, Xiaotian; Wu, Nan; Tian, Ye; Zhang, Yang; Fitek, John; Maffeo, Michael; Niezrecki, Christopher; Chen, Julie; Wang, Xingwei

2013-02-20

A shock wave (SW) is characterized as a large pressure fluctuation that typically lasts only a few milliseconds. On the battlefield, SWs pose a serious threat to soldiers who are exposed to explosions, which may lead to blast-induced traumatic brain injuries. SWs can also be used beneficially and have been applied to a variety of medical treatments due to their unique interaction with tissues and cells. Consequently, it is important to have sensors that can quantify SW dynamics in order to better understand the physical interaction between body tissue and the incident acoustic wave. In this paper, the ultrafast fiber-optic sensor based on the Fabry-Perot interferometric principle was designed and four such sensors were fabricated to quantify a blast event within different media, simultaneously. The compact design of the fiber-optic sensor allows for a high degree of spatial resolution when capturing the wavefront of the traveling SW. Several blast event experiments were conducted within different media (e.g., air, rubber membrane, and water) to evaluate the sensor's performance. This research revealed valuable knowledge for further study of SW behavior and SW-related applications.

Analysis and design of tunable wideband microwave photonics phase shifter based on Fabry-Perot cavity and Bragg mirrors in silicon-on-insulator waveguide.

Science.gov (United States)

Qu, Pengfei; Zhou, Jingran; Chen, Weiyou; Li, Fumin; Li, Haibin; Liu, Caixia; Ruan, Shengping; Dong, Wei

2010-04-20

We designed a microwave (MW) photonics phase shifter, consisting of a Fabry-Perot filter, a phase modulation region (PMR), and distributed Bragg reflectors, in a silicon-on-insulator rib waveguide. The thermo-optics effect was employed to tune the PMR. It was theoretically demonstrated that the linear MW phase shift of 0-2pi could be achieved by a refractive index variation of 0-9.68x10(-3) in an ultrawideband (about 38?GHz-1.9?THz), and the corresponding tuning resolution was about 6.92 degrees / degrees C. The device had a very compact size. It could be easily integrated in silicon optoelectronic chips and expected to be widely used in the high-frequency MW photonics field.

Performance Evaluation of Fabry-Perot Temperature Sensors in Nuclear Power Plant Measurements

International Nuclear Information System (INIS)

Liu Hanying; Miller, Don W.; Talnagi, Joseph W.

2003-01-01

The Fiso Fabry-Perot fiber-optic temperature sensor was selected for performance evaluation and for potential application in nuclear power plants because of its unique interferometric sensing mechanism and data-processing technique, and its commercial availability. It employs a Fizeau interferometer and a charge-coupled device array to locate the position of the maximum interference fringe intensity, which is directly related to the environmental temperature. Consequently, the basic sensing mechanism is independent of the absolute transmitted light intensity, which is the most likely parameter to be affected by external harsh environments such as nuclear irradiation, high pressure/temperature, and cyclical vibration.This paper reports research on the performance of two Fiso Fabry-Perot temperature sensors in environmental conditions expected in nuclear power plants during both normal and abnormal (i.e., accident) conditions. The environmental conditions simulated in this paper include gamma-only ( 60 Co) irradiation, pressure/temperature environmental transient, and mixed neutron/gamma field, respectively.The first sensor exhibited no failure or degradation in performance during and following gamma-only irradiation in which a total dose of 15 kGy was delivered at a dose rate of 2.5 kGy/h. Following gamma irradiation, this sensor was then tested for 10.75 days in a thermohydraulic environment prescribed by the Institute of Electrical and Electronics Engineers IEEE323-1983. Intermittent behavior was observed throughout the latter portions of this test, and degradation in performance occurred after the test. Visual evaluation after opening the sensor head indicated that the internal welding methodology was the primary contributor to the observed behavior during this test. Further consultation with the vendor shows that the robustness and reliability of Fiso sensors can be substantially improved by modifying the internal welding methods.The second Fiso temperature

Non-destructive residual pressure self-measurement method for the sensing chip of optical Fabry-Perot pressure sensor.

Science.gov (United States)

Wang, Xue; Wang, Shuang; Jiang, Junfeng; Liu, Kun; Zhang, Xuezhi; Xiao, Mengnan; Xiao, Hai; Liu, Tiegen

2017-12-11

We introduce a simple residual pressure self-measurement method for the Fabry-Perot (F-P) cavity of optical MEMS pressure sensor. No extra installation is required and the structure of the sensor is unchanged. In the method, the relationship between residual pressure and external pressure under the same diaphragm deflection condition at different temperatures is analyzed by using the deflection formula of the circular plate with clamped edges and the ideal gas law. Based on this, the residual pressure under the flat condition can be obtained by pressure scanning process and calculation process. We carried out the experiment to compare the residual pressures of two batches MEMS sensors fabricated by two kinds of bonding process. The measurement result indicates that our approach is reliable enough for the measurement.

Hα Intensity Map of the Repeating Fast Radio Burst FRB 121102 Host Galaxy from Subaru/Kyoto 3DII AO-assisted Optical Integral-field Spectroscopy

Science.gov (United States)

Kokubo, Mitsuru; Mitsuda, Kazuma; Sugai, Hajime; Ozaki, Shinobu; Minowa, Yosuke; Hattori, Takashi; Hayano, Yutaka; Matsubayashi, Kazuya; Shimono, Atsushi; Sako, Shigeyuki; Doi, Mamoru

2017-08-01

We present the Hα intensity map of the host galaxy of the repeating fast radio burst FRB 121102 at a redshift of z = 0.193 obtained with the AO-assisted Kyoto 3DII optical integral-field unit mounted on the 8.2 m Subaru Telescope. We detected a compact Hα-emitting (I.e., star-forming) region in the galaxy, which has a much smaller angular size (GMOS z\\prime -band image (≃ 1\\buildrel{\\prime\\prime}\\over{.} 4 (4.6 kpc) at FWHM with ellipticity b/a=0.45). The spatial offset between the centroid of the Hα emission region and the position of the radio bursts is 0\\buildrel{\\prime\\prime}\\over{.} 08+/- 0\\buildrel{\\prime\\prime}\\over{.} 02 (0.26 ± 0.07 kpc), indicating that FRB 121102 is located within the star-forming region. This close spatial association of FRB 121102 with the star-forming region is consistent with expectations from young pulsar/magnetar models for FRB 121102, and it also suggests that the observed Hα emission region can make a major dispersion measure (DM) contribution to the host galaxy DM component of FRB 121102. Nevertheless, the largest possible value of the DM contribution from the Hα emission region inferred from our observations still requires a significant amount of ionized baryons in intergalactic medium (IGM; the so-called “missing” baryons) as the DM source of FRB 121102, and we obtain a 90% confidence level lower limit on the cosmic baryon density in the IGM in the low-redshift universe as {{{Ω }}}{IGM}> 0.012. Based on data collected at Subaru Telescope, which is operated by the National Astronomical Observatory of Japan.

The PVLAS experiment: measuring vacuum magnetic birefringence and dichroism with a birefringent Fabry-Perot cavity

Energy Technology Data Exchange (ETDEWEB)

Della Valle, Federico; Milotti, Edoardo [INFN, Trieste (Italy); Universita di Trieste, Dipt. di Fisica, Trieste (Italy); Ejlli, Aldo; Messineo, Giuseppe; Zavattini, Guido [INFN, Ferrara (Italy); Universita di Ferrara, Dipt. di Fisica e Scienze della Terra, Ferrara (Italy); Gastaldi, Ugo [INFN, Ferrara (Italy); Pengo, Ruggero; Ruoso, Giuseppe [INFN, Lab. Nazionale di Legnaro, Legnaro (Italy)

2016-01-15

Vacuum magnetic birefringence was predicted long time ago and is still lacking a direct experimental confirmation. Several experimental efforts are striving to reach this goal, and the sequence of results promises a success in the next few years. This measurement generally is accompanied by the search for hypothetical light particles that couple to two photons. The PVLAS experiment employs a sensitive polarimeter based on a high finesse Fabry-Perot cavity. In this paper we report on the latest experimental results of this experiment. The data are analysed taking into account the intrinsic birefringence of the dielectric mirrors of the cavity. Besides a new limit on the vacuum magnetic birefringence, the measurements also allow the model-independent exclusion of new regions in the parameter space of axion-like and milli-charged particles. In particular, these last limits hold also for all types of neutrinos, resulting in a laboratory limit on their charge. (orig.)

InP femtosecond mode-locked laser in a compound feedback cavity with a switchable repetition rate

Science.gov (United States)

Lo, Mu-Chieh; Guzmán, Robinson; Carpintero, Guillermo

2018-02-01

A monolithically integrated mode-locked semiconductor laser is proposed. The compound ring cavity is composed of a colliding pulse mode-locking (ML) subcavity and a passive Fabry-Perot feedback subcavity. These two 1.6 mm long subcavities are coupled by using on-chip reflectors at both ends, enabling harmonic mode locking. By changing DC-bias conditions, optical mode spacing from 50 to 450 GHz is experimentally demonstrated. Ultrafast pulses shorter than 0.3 ps emitted from this laser diode are shown in autocorrelation traces.

A new method for multi-channel Fabry-Perot spectroscopy of light pulses in the nanosecond regime

International Nuclear Information System (INIS)

Behn, R.

1975-01-01

The demand for powerful multichannel spectrometers raised, e.g., in laser scattering plasma diagnostics, gave rise to the question if it would not be possible to avoid the light losses occuring in the use of multichannel Fabry-Perot spectrometers. These losses can be avoided with the technique presented here. The reflected light is collected and fed back to the interferometer at a different angle. It can thus be recovered for registration in another spectral channel. This method is particularly suitable for the investigation of short light pulses. A spectrum can thus be scanned step by step with full utilization of the transit time of the light pulse. In addition to light recovery, there is another advantage in that only one detector is used for multichannel analysis, thus eliminating calibration problems. In the annex to the report, emission spectres of different dye laser versions are presented and explained. (orig./GG) [de

Amplification of the Signal Intensity of Fluorescence-Based Fiber-Optic Biosensors Using a Fabry-Perot Resonator Structure

Directory of Open Access Journals (Sweden)

Meng-Chang Hsieh

2015-02-01

Full Text Available Fluorescent biosensors have been widely used in biomedical applications. To amplify the intensity of fluorescence signals, this study developed a novel structure for an evanescent wave fiber-optic biosensor by using a Fabry-Perot resonator structure. An excitation light was coupled into the optical fiber through a laser-drilled hole on the proximal end of the resonator. After entering the resonator, the excitation light was reflected back and forth inside the resonator, thereby amplifying the intensity of the light in the fiber. Subsequently, the light was used to excite the fluorescent molecules in the reactive region of the sensor. The experimental results showed that the biosensor signal was amplified eight-fold when the resonator reflector was formed using a 92% reflective coating. Furthermore, in a simulation, the biosensor signal could be amplified 20-fold by using a 99% reflector.

Mirror Birefringence in a Fabry-Perot Cavity and the Detection of Vacuum Birefringence in a Magnetic Field

Science.gov (United States)

Chui, T. C. P.; Shao, M.; Redding, D.; Gursel, Y.; Boden, A.

1995-01-01

We discuss the effect of mirror birefringence in two optical schemes designed to detect the quantum-electrodynamics (QED) predictions of vacuum birefringence under the influence of a strong magnetic field, B. Both schemes make use of a high finesse Fabry-Perot cavity (F-P) to increase the average path length of the light in the magnetic field. The first scheme, which we called the frequency scheme, is based on measurement of the beat frequency of two orthogonal polarized laser beams in the cavity. We show that mirror birefringence contributes to the detection uncertainties in first order, resulting in a high susceptibility to small thermal disturbances. We estimate that an unreasonably high thermal stability of 10-9 K is required to resolve the effect to 0.1%. In the second scheme, which we called the polarization rotation scheme, laser polarized at 45 relative to the B field is injected into the cavity.

A high-transmission liquid-crystal Fabry-Perot infrared filter for electrically tunable spectral imaging detection

Science.gov (United States)

Liu, Zhonglun; Xin, Zhaowei; Long, Huabao; Wei, Dong; Dai, Wanwan; Zhang, Xinyu; Wang, Haiwei; Xie, Changsheng

2018-02-01

Previous studies have presented the usefulness of typical liquid-crystal Fabry-Perot (LC-FP) infrared filters for spectral imaging detection. Yet, their infrared transmission performances still remain to improve or even rise. In this paper, we propose a new type of electrically tunable LC-FP infrared filter to solve the problem above. The key component of the device is a FP resonant cavity composed of two parallel plane mirrors, in which the zinc selenide (ZnSe) materials with a very high transmittance in the mid-long-wavelength infrared regions are used as the electrode substrates and a layer of nano-aluminum (Al) film, which is directly contacted with liquid-crystal materials, is chosen to make high reflective mirrors as well as the electrodes. Particularly, it should be noted that the directional layer made up of ployimide (PI) used previously is removed. The experiment results indicate that the filter can reduce the absorption of infrared wave remarkably, and thus highlight a road to effectively improve the infrared transmittance ability.

Study of luminescence and optical resonances in Sb{sub 2}O{sub 3} micro- and nanotriangles

Energy Technology Data Exchange (ETDEWEB)

Cebriano, Teresa; Mendez, Bianchi, E-mail: bianchi@fis.ucm.es; Piqueras, Javier [Universidad Complutense de Madrid, Departamento de Fisica de Materiales, Facultad de Ciencias Fisicas (Spain)

2012-10-15

Luminescence of micro- and nanotriangles of cubic antimony oxide, Sb{sub 2}O{sub 3} has been investigated by cathodoluminescence (CL) in scanning electron microscope and by photoluminescence (PL) in a laser confocal microscope. The triangles were grown by a thermal evaporation-deposition process with pure antimony powders as precursor, and present a self assembled arrangement covering extended areas of the samples. CL spectra of the triangles show bands at 2-2.5 and 3.1 eV, the latter is not observed in the Sb{sub 2}O{sub 3} initial powder. PL excited by 325 nm laser shows a band at 2.4 eV with a shoulder at 2.75 eV, as well as resonance modes suggesting optical cavity behavior of the triangles. The separation between resonant peaks from different triangles has been correlated with the triangle side length and possible optical paths were obtained according to the Fabry-Perot relationship. These results along with the optical images suggest that not only Fabry-Perot cavity modes, but also whispering gallery modes may occur inside the micro- and nanotriangle structures.

Comparative analysis of frequency and noise characteristics of Fabry – Perot and distributed feedback laser diodes with external optical injection locking

Energy Technology Data Exchange (ETDEWEB)

Afonenko, A A; Dorogush, E S [Belarusian State University, Minsk (Belarus); Malyshev, S A; Chizh, A L [B.I. Stepanov Institute of Physics, National Academy of Sciences of Belarus, Minsk (Belarus)

2015-11-30

Using a system of coupled travelling wave equations, in the small-signal regime we analyse frequency and noise characteristics of index- or absorption-coupled distributed feedback laser diodes, as well as of Fabry – Perot (FP) laser diodes. It is shown that the weakest dependence of the direct modulation efficiency on the locking frequency in the regime of strong external optical injection locking is exhibited by a FP laser diode formed by highly reflective and antireflective coatings on the end faces of a laser structure. A reduction in the dependence of output characteristics of the laser diode on the locking frequency can be attained by decreasing the reflection coefficient of the antireflective FP mirror. (control of laser radiation parameters)

Fiber Fabry-Perot Force Sensor with Small Volume and High Performance for Assessing Fretting Damage of Steam Generator Tubes.

Science.gov (United States)

Huang, Peijian; Wang, Ning; Li, Junying; Zhu, Yong; Zhang, Jie

2017-12-13

Measuring the radial collision force between the steam generator tube (SGT) and the tube support plate (TSP) is essential to assess the fretting damage of the SGT. In order to measure the radial collision force, a novel miniaturized force sensor based on fiber Fabry-Perot (F-P) was designed, and the principle and characteristics of the sensor were analyzed in detail. Then, the F-P force sensor was successfully fabricated and calibrated, and the overall dimensions of the encapsulated fiber F-P sensor were 17 mm × 5 mm × 3 mm (L × W × H). The sensor works well in humid, high pressure (10 MPa), high temperature (350 °C), and vibration (40 kHz) environments. Finally, the F-P force sensors were installed in a 1:1 steam generator test loop, and the radial collision force signals between the SGT and the TSP were obtained. The experiments indicated that the F-P sensor with small volume and high performance could help in assessing the fretting damage of the steam generator tubes.

Intra-Tissue Pressure Measurement in Ex Vivo Liver Undergoing Laser Ablation with Fiber-Optic Fabry-Perot Probe

Directory of Open Access Journals (Sweden)

Daniele Tosi

2016-04-01

Full Text Available We report the first-ever intra-tissue pressure measurement performed during 1064 nm laser ablation (LA of an ex vivo porcine liver. Pressure detection has been performed with a biocompatible, all-glass, temperature-insensitive Extrinsic Fabry-Perot Interferometry (EFPI miniature probe; the proposed methodology mimics in-vivo treatment. Four experiments have been performed, positioning the probe at different positions from the laser applicator tip (from 0.5 mm to 5 mm. Pressure levels increase during ablation time, and decrease with distance from applicator tip: the recorded peak parenchymal pressure levels range from 1.9 kPa to 71.6 kPa. Different pressure evolutions have been recorded, as pressure rises earlier in proximity of the tip. The present study is the first investigation of parenchymal pressure detection in liver undergoing LA: the successful detection of intra-tissue pressure may be a key asset for improving LA, as pressure levels have been correlated to scattered recurrences of tumors by different studies.

Combined incoherent scatter radar and Fabry-Perot interferometer measurements of frictional heating effects over Millstone Hill during March 7-10, 1989

International Nuclear Information System (INIS)

Hagan, M.E.; Sipler, D.P.

1991-01-01

The authors introduce a methodology to calculate the effects of frictional heating associated with geomagnetic activity using simultaneous incoherent scatter radar and Fabry-Perot interferometer measurements. Vector measurements of ion drift from radar backscatter and neutral wind from optical shifts in the atomic oxygen red line over Millstone Hill, Massachusetts (43 degree N) for the nights of March 7-10, 1989 are presented and are characterized by the magnetic storm activity which prevailed. They combine these measurements to calculate differences in the ion and neutral velocity fields which approach 350 m/s during the most geomagnetically active period that they monitored near 01 UT on March 9. This velocity difference results in a 110 degree K heating of the ion gas at that time

High-accuracy vibration sensor based on a Fabry-Perot interferometer with active phase-tracking technology.

Science.gov (United States)

Xia, Wei; Li, Chuncheng; Hao, Hui; Wang, Yiping; Ni, Xiaoqi; Guo, Dongmei; Wang, Ming

2018-02-01

A novel position-sensitive Fabry-Perot interferometer was constructed with direct phase modulation by a built-in electro-optic modulator. Pure sinusoidal phase modulation of the light was produced, and the first harmonic of the interference signal was extracted to dynamically maintain the interferometer phase to the most sensitive point of the interferogram. Therefore, the minute vibration of the object was coded on the variation of the interference signal and could be directly retrieved by the output voltage of a photodetector. The operating principle and the signal processing method for active feedback control of the interference phase have been demonstrated in detail. The developed vibration sensor was calibrated through a high-precision piezo-electric transducer and tested by a nano-positioning stage under a vibration magnitude of 60 nm and a frequency of 300 Hz. The active phase-tracking method of the system provides high immunity against environmental disturbances. Experimental results show that the proposed interferometer can effectively reconstruct tiny vibration waveforms with subnanometer resolution, paving the way for high-accuracy vibration sensing, especially for micro-electro-mechanical systems/nano-electro-mechanical systems and ultrasonic devices.

Cost-effective optical fiber pressure sensor based on intrinsic Fabry-Perot interferometric micro-cavities

Science.gov (United States)

Domingues, M. Fátima; Rodriguez, Camilo A.; Martins, Joana; Tavares, Cátia; Marques, Carlos; Alberto, Nélia; André, Paulo; Antunes, Paulo

2018-05-01

In this work, a cost-effective procedure to manufacture optical fiber pressure sensors is presented. This has a high relevance for integration in robotic exoskeletons or for gait plantar pressure monitoring within the physical rehabilitation scenarios, among other applications. The sensing elements are based on Fabry-Perot interferometric (FPI) micro-cavities, created from the recycling of optical fibers previously destroyed by the catastrophic fuse effect. To produce the pressure sensors, the fiber containing the FPI micro-cavities was embedded in an epoxy resin cylinder used as pressure transducer and responsible to transfer the pressure applied on its surface to the optical fiber containing the FPI micro-cavity. Before the embedding process, some FPI sensors were also characterized to strain variations. After that, the effect of the encapsulation of the FPI structure into the resin was assessed, from which a slight decrease on the FPI interferogram fringes visibility was verified, indicating a small increase in the micro-cavity length. Up on the sensors characterization, a linear dependence of the wavelength shift with the induced pressure was obtained, which leads to a maximum sensitivity of 59.39 ± 1.7 pm/kPa. Moreover, direct dependence of the pressure sensitivity with the micro-cavity volume and length was found.

Use of a Fabry-Perot resonator at millimeter wave frequencies in the determination of thin-film resistivities

Energy Technology Data Exchange (ETDEWEB)

Hogan, S. J.

1979-08-01

A novel contact-free method of measuring resistivity of thin semiconducting films on highly conductive substrates is described. The material structure studied is commonly encountered in thin-film solar cell development. The microwave technique that involves using a semiconfocal Fabry-Perot cavity at a wavelength of 3 mm is discussed in detail. The sample consists o a thin film of CdS on a brass substrate and is mounted on the flat reflector of the cavity. Using field perturbation methods, an expression is derived that relates the film resistivity to the cavity quality factor Q. The cavity quality factor is an easily measured parameter and, by comparing measurements of Q with and without the sample mounted, an accurate measure of the resistivity is obtained. Accuracy of measurements and necessary sample constraints are discussed in detail. Three samples of CdS were measured on brass substrates spanning an order of magnitude in resistivity difference. The results of the method described agree with those of another method that involves current voltage measurement after application of a metallic contact. Unlike the latter method, however, the new technique provides a nondestructive way of measuring the resistivity of semiconductor films on conducting substrates and is amenable to automation.

Association between Dietary Inflammatory Index (DII) and risk of prediabetes: a case-control study.

Science.gov (United States)

Vahid, Farhad; Shivappa, Nitin; Karamati, Mohsen; Naeini, Alireza Jafari; Hebert, James R; Davoodi, Sayed Hossein

2017-04-01

The possible relationship between diet-related inflammation and the risk of prediabetes requires further investigation, especially in non-Western populations. We examined the ability of the dietary inflammatory index (DII) to predict the risk of prediabetes in a case-control study conducted at specialized centers in Esfahan, Iran. A total of 214 incident cases of prediabetes were selected with the nonrandom sampling procedure, and the 200 controls randomly selected from the same clinics were frequency-matched on age (±5 years) and sex. DII scores were computed based on dietary intake assessed using a validated and reproducible 168-item food-frequency questionnaire. Linear and logistic regression models were used to estimate multivariable beta estimates and odds ratios (ORs). Subjects in tertile 3 versus tertile 1 (T3VS1) of DII had significantly higher fasting plasma glucose (DII T3VS1 : b = 4.49; 95% CI 1.89, 7.09), oral glucose tolerance (DII T3VS1 : b = 8.76; 95% CI 1.78, 15.73), HbA1c (DII T3VS1 : b = 0.30; 95% CI 0.17, 0.42), low-density lipoprotein (DII T3VS1 : b = 16.37; 95% CI 11.04, 21.69), triglyceride (DII T3VS1 : b = 21.01; 95% CI 8.61, 33.42) and body fat (DII T3VS1 : b = 2.41; 95% CI 0.56, 4.26) and lower high-density lipoprotein (DII T3VS1 : b = -3.39; 95% CI -5.94, -0.84) and lean body mass (DII T3VS1 : b = -3.11; 95% CI -4.83, -1.39). After multivariate adjustment, subjects in the most pro-inflammatory DII group had 19 times higher odds of developing prediabetes compared with subjects in tertile 1 (DII T3VS1 : OR = 18.88; 95% CI 7.02, 50.82). Similar results were observed when DII was used as a continuous variable, (DII continuous : OR = 3.62; 95% CI 2.50, 5.22). Subjects who consumed a more pro-inflammatory diet were at increased risk of prediabetes compared with those who consumed a more anti-inflammatory diet.

Single mode operation of a TEA CO2 laser

International Nuclear Information System (INIS)

Wada, Kazuhiro; Tunawaki, Yoshiaki; Yamanaka, Masanobu.

1993-01-01

Single mode operation of a TEA CO 2 laser was performed by using an optical system of Fox-Smith type. Laser beam was taken out from the cavity by using a beam splitter, and was reflected by a mirror back to the cavity. By inserting a Fabry-Perot etalon between the splitter and the mirror, beat of laser pulses can be removed completly. (author)

A pulsated weak-resonant-cavity laser diode with transient wavelength scanning and tracking for injection-locked RZ transmission.

Science.gov (United States)

Lin, Gong-Ru; Chi, Yu-Chieh; Liao, Yu-Sheng; Kuo, Hao-Chung; Liao, Zhi-Wang; Wang, Hai-Lin; Lin, Gong-Cheng

2012-06-18

By spectrally slicing a single longitudinal-mode from a master weak-resonant-cavity Fabry-Perot laser diode with transient wavelength scanning and tracking functions, the broadened self-injection-locking of a slave weak-resonant-cavity Fabry-Perot laser diode is demonstrated to achieve bi-directional transmission in a 200-GHz array-waveguide-grating channelized dense-wavelength-division-multiplexing passive optical network system. Both the down- and up-stream slave weak-resonant-cavity Fabry-Perot laser diodes are non-return-to-zero modulated below threshold and coherently injection-locked to deliver the pulsed carrier for 25-km bi-directional 2.5 Gbits/s return-to-zero transmission. The master weak-resonant-cavity Fabry-Perot laser diode is gain-switched at near threshold condition and delivers an optical coherent pulse-train with its mode linewidth broadened from 0.2 to 0.8 nm by transient wavelength scanning, which facilitates the broadband injection-locking of the slave weak-resonant-cavity Fabry-Perot laser diodes with a threshold current reducing by 10 mA. Such a transient wavelength scanning induced spectral broadening greatly releases the limitation on wavelength injection-locking range required for the slave weak-resonant-cavity Fabry-Perot laser diode. The theoretical modeling and numerical simulation on the wavelength scanning and tracking effects of the master and slave weak-resonant-cavity Fabry-Perot laser diodes are performed. The receiving power sensitivity for back-to-back transmission at bit-error-rate transmission is less than 2 dB for all 16 channels.

Research and investigation of a communication chain on optical fiber with a Fabry-Perot power diode for the automotive industry

Science.gov (United States)

Bacis, Irina Bristena; Vasile, Alexandru; Ionescu, Ciprian; Marghescu, Cristina

2016-12-01

The purpose of this paper is to analyze different power devices - emitters of optical flow, from the point of view of optical coupling, emitted optical powers, optical fiber losses and receiver. The research and characterization of the transmission through a power optical system is done using a computer system specialized for the automotive industry. This system/platform can deliver current pulses that are controlled by a computer through a software (it is possible to set different parameters such as pulse repetition frequency, duty cycle, and current intensity). For the experiments a power Fabry Perot 1035 laser diode operating in pulse with μφ 1055 nm, Ith = 40 mA, and Iop =750 mA was used with a single-mode SFM 128 optical fiber and an EM type optical coupler connected through alignment. Two types of measurements were conducted to demonstrate the usefulness of the experimental structure. In the first case the amplitude of the voltage pulses was measured at the output of an optical detector with receiving diode in a built-in amplifier with a 50 kΩ load resistance. In the second stage measurements were conducted to determine the optical power injected in the optical fiber and received at the reception cell of a power meter. Another parameter of optical coupling that can be measured using the experimental structure is irradiation. This parameter is very important to determine the optimum cutting angle of the fiber for continuity welding.

Heterogeneous Silicon III-V Mode-Locked Lasers

Science.gov (United States)

Davenport, Michael Loehrlein

Mode-locked lasers are useful for a variety of applications, such as sensing, telecommunication, and surgical instruments. This work focuses on integrated-circuit mode-locked lasers: those that combine multiple optical and electronic functions and are manufactured together on a single chip. While this allows production at high volume and lower cost, the true potential of integration is to open applications for mode-locked laser diodes where solid state lasers cannot fit, either due to size and power consumption constraints, or where small optical or electrical paths are needed for high bandwidth. Unfortunately, most high power and highly stable mode-locked laser diode demonstrations in scientific literature are based on the Fabry-Perot resonator design, with cleaved mirrors, and are unsuitable for use in integrated circuits because of the difficulty of producing integrated Fabry-Perot cavities. We use silicon photonics and heterogeneous integration with III-V gain material to produce the most powerful and lowest noise fully integrated mode-locked laser diode in the 20 GHz frequency range. If low noise and high peak power are required, it is arguably the best performing fully integrated mode-locked laser ever demonstrated. We present the design methodology and experimental pathway to realize a fully integrated mode-locked laser diode. The construction of the device, beginning with the selection of an integration platform, and proceeding through the fabrication process to final optimization, is presented in detail. The dependence of mode-locked laser performance on a wide variety of design parameters is presented. Applications for integrated circuit mode-locked lasers are also discussed, as well as proposed methods for using integration to improve mode-locking performance to beyond the current state of the art.

Fabry-Perot magnonic ballistic coherent transport across ultrathin ferromagnetic lamellar bcc Ni nanostructures between Fe leads

Science.gov (United States)

Khater, A.; Saim, L.; Tigrine, R.; Ghader, D.

2018-06-01

We propose thermodynamically stable systems of ultrathin lamellar bcc Ni nanostructures between bcc Fe leads, sbnd Fe[Ni(n)]Fesbnd , based on the available literature for bcc Ni overlayers on Fe(001) surfaces, and establish the necessary criteria for their structural and ferromagnetic order, for thicknesses n ≤ 6 bcc Ni monatomic layers. The system is globally ferromagnetic. A theoretical model is presented to investigate and understand the ballistic coherent scattering of Fe spin-waves, incident from the leads, at the ferromagnetic bcc Ni nanostructure. The Nisbnd Ni and Nisbnd Fe exchange are computed using the Ising effective field theory (EFT), and the magnetic ground state of the system is constructed in the Heisenberg representation. We compute the spin-wave eigenmodes localized on the bcc Ni nanostructure, using the phase field matching theory (PFMT), illustrating the effects of symmetry breaking on the confinement of localized spin excitations. The reflection and transmission scattering properties of spin-waves incident from the Fe leads, across the embedded Ni nanostructures are investigated within the framework of the same PFMT methodology. A highly refined Fabry-Perot magnonic ballistic coherent transmission spectra is observed for these sbnd Fe[Ni(n)]Fesbnd systems.

The Gain Estimation of a Fabry-Perot Cavity (FPC Antenna with a Finite Dimension

Directory of Open Access Journals (Sweden)

Taek-Sun Kwon

2017-10-01

Full Text Available In this paper, we have presented an equation for estimating the gain of a Fabry-Perot cavity (FPC antenna with a finite dimension. When an FPC antenna has an infinite dimension and its height is half of a wavelength, the maximum gain of that FPC antenna can be obtained theoretically. If the FPC antenna does not have a dimension sufficient for multiple reflections between a partially reflective surface (PRS and the ground, its gain must be less than that of an FPC antenna that has an infinite dimension. In addition, the gain of an FPC antenna increases as the dimension of a PRS increases and becomes saturated from a specific dimension. The specific dimension where the gain starts to saturate also gets larger as the reflection magnitude of the PRS becomes closer to one. Thus, it would be convenient to have a gain equation when considering the dimension of an FPC antenna in order to estimate the exact gain of the FPC antenna with a specific dimension. A gain versus the dimension of the FPC antenna for various reflection magnitudes of PRS has been simulated, and the modified gain equation is produced through the curve fitting of the full-wave simulation results. The resulting empirical gain equation of an FPC antenna whose PRS dimension is larger than 1.5λ0 has been obtained.

Measurement of Microvibration by Using Dual-Cavity Fiber Fabry-Perot Interferometer for Structural Health Monitoring

Directory of Open Access Journals (Sweden)

Dae-Hyun Kim

2014-01-01

Full Text Available Extensive researches have recently been performed to study structural integrity using structural vibration data measured by in-structure sensors. A fiber optic sensor is one of candidates for the in-structure sensors because it is low in cost, light in weight, small in size, resistant to EM interference, long in service life, and so forth. Especially, an interferometric fiber optic sensor is very useful to measure vibrations with high resolution and accuracy. In this paper, a dual-cavity fiber Fabry-Perot interferometer was proposed with a phase-compensating algorithm for measuring micro-vibration. The interferometer has structurally two arbitrary cavities; therefore the initial phase difference between two sinusoidal signals induced from the interferometer was also arbitrary. In order to do signal processing including an arc-tangent method, a random value of the initial phase difference is automatically adjusted to the exact 90 degrees in the phase-compensating algorithm part. For the verification of the performance of the interferometer, a simple vibration-test was performed to measure micro-vibration caused by piezoelectric transducer (PZT. As an experimental result, the interferometer attached on the PZT successfully measured the 50 Hz-vibration of which the absolute displacement oscillated between −424 nm and +424 nm.

Ground-based Fabry-Perot interferometry of the terrestrial nightglow with a bare charge-coupled device; Remote field site deployment

International Nuclear Information System (INIS)

Niciejewski, R.; Killeen, T.L.; Turnbull, M.

1994-01-01

The application of Fabry-Perot interferometers (FPIs) to the study of upper atmosphere thermodynamics has largely been restricted by the very low light levels in the terrestrial airglow as well as the limited range in wavelength of photomultiplier tube (PMT) technology. During the past decade, the development of the scientific grade charge-coupled device (CCD) has progressed to the stage in which the detector has become the logical replacement for the PMT. Small fast microcomputers have made it possible to ''upgrade'' the remote field sites which bare CCDs and not only retain the previous capabilities of the existing FPIs but expand the data coverage in both temporal and wavelength domains. The problems encountered and the solutions applied to the deployment of a bare CCD, with data acquisition and image reduction techniques, are discussed. Sample geophysical data determined from the FPI fringe profiles are shown for stations at Peach Mountain, Michigan, and Watson Lake, Yukon Territory

Effect of Surface Plasmon Coupling to Optical Cavity Modes on the Field Enhancement and Spectral Response of Dimer-Based sensors

KAUST Repository

Alrasheed, Salma; Di Fabrizio, Enzo M.

2017-01-01

with the resonant modes of a Fabry-Perot (FP) cavity. The strong coupling is demonstrated by the large anticrossing in the reflection spectra and a Rabi splitting of 76 meV. Up to 2-fold enhancement increase can be achieved compared to that without using the cavity

Performance of a distributed simultaneous strain and temperature sensor based on a Fabry-Perot laser diode and a dual-stage FBG optical demultiplexer.

Science.gov (United States)

Kim, Suhwan; Kwon, Hyungwoo; Yang, Injae; Lee, Seungho; Kim, Jeehyun; Kang, Shinwon

2013-11-12

A simultaneous strain and temperature measurement method using a Fabry-Perot laser diode (FP-LD) and a dual-stage fiber Bragg grating (FBG) optical demultiplexer was applied to a distributed sensor system based on Brillouin optical time domain reflectometry (BOTDR). By using a Kalman filter, we improved the performance of the FP-LD based OTDR, and decreased the noise using the dual-stage FBG optical demultiplexer. Applying the two developed components to the BOTDR system and using a temperature compensating algorithm, we successfully demonstrated the simultaneous measurement of strain and temperature distributions under various experimental conditions. The observed errors in the temperature and strain measured using the developed sensing system were 0.6 °C and 50 με, and the spatial resolution was 1 m, respectively.

The noise of ultrashort pulse mode-locked lasers beyond the slowly varying envelope approximation

International Nuclear Information System (INIS)

Takushima, Y; Haus, H A; Kaertner, F X

2004-01-01

The zero-point fluctuations in an L-C circuit of finite Q are revisited. The zero-point energy is shown to approach the value of hbarω 0 /2 only in the limit of an infinite Q. A Fabry-Perot resonator, on the other hand, has bounded zero-point energies of its modes that are equal to hbarω n /2 for each resonance. Based on the Fabry-Perot resonator with broadband noise, we analyse the noise of an ultrafast mode-locked laser when the slowly varying envelope approximation (SVEA) is not valid. This is achieved by reinterpreting the quantized form of the master equation of mode locking as an equation of motion for the electric field rather than for the creation operator of a photon. It is found that in this formulation quantum correlations exist that are not present in the SVEA. The correlations become evident in the spectrum of the zero-point fluctuations and therefore in the background noise of the laser. This behaviour can be detected by homodyne detection of the laser output. The linewidth of the frequency comb generated by the mode-locked laser is not affected by these correlations and is given by the Schawlow-Townes linewidth of an equivalent continuous wave taking the additional intracavity loss due to the mode locking process into account

DiI Perfusion as a Method for Vascular Visualization in Ambystoma mexicanum.

Science.gov (United States)

Saltman, Anna J; Barakat, May; Bryant, Donald M; Brodovskaya, Anastasia; Whited, Jessica L

2017-06-16

Perfusion techniques have been used for centuries to visualize the circulation of tissues. Axolotl (Ambystoma mexicanum) is a species of salamander that has emerged as an essential model for regeneration studies. Little is known about how revascularization occurs in the context of regeneration in these animals. Here we report a simple method for visualization of the vasculature in axolotl via perfusion of 1,1'-Dioctadecy-3,3,3',3'-tetramethylindocarbocyanine perchlorate (DiI). DiI is a lipophilic carbocyanine dye that inserts into the plasma membrane of endothelial cells instantaneously. Perfusion is done using a peristaltic pump such that DiI enters the circulation through the aorta. During perfusion, dye flows through the axolotl's blood vessels and incorporates into the lipid bilayer of vascular endothelial cells upon contact. The perfusion procedure takes approximately one hour for an eight-inch axolotl. Immediately after perfusion with DiI, the axolotl can be visualized with a confocal fluorescent microscope. The DiI emits light in the red-orange range when excited with a green fluorescent filter. This DiI perfusion procedure can be used to visualize the vascular structure of axolotls or to demonstrate patterns of revascularization in regenerating tissues.

Mode conversion in metal-insulator-metal waveguide with a shifted cavity

Science.gov (United States)

Wang, Yueke; Yan, Xin

2018-01-01

We propose a method, which is utilized to achieve the plasmonic mode conversion in metal-insulator-metal (MIM) waveguide, theoretically. Our proposed structure is composed of bus waveguides and a shifted cavity. The shifted cavity can choose out a plasmonic mode (a- or s-mode) when it is in Fabry-Perot (FP) resonance. The length of the shifted cavity L is carefully chosen, and our structure can achieve the mode conversion between a- and s-mode in the communication region. Besides, our proposed structure can also achieve plasmonic mode-division multiplexing. All the numerical simulations are carried on by the finite element method to verify our design.

Simple locking of infrared and ultraviolet diode lasers to a visible laser using a LabVIEW proportional-integral-derivative controller on a Fabry-Perot signal.

Science.gov (United States)

Kwolek, J M; Wells, J E; Goodman, D S; Smith, W W

2016-05-01

Simultaneous laser locking of infrared (IR) and ultraviolet lasers to a visible stabilized reference laser is demonstrated via a Fabry-Perot (FP) cavity. LabVIEW is used to analyze the input, and an internal proportional-integral-derivative algorithm converts the FP signal to an analog locking feedback signal. The locking program stabilized both lasers to a long term stability of better than 9 MHz, with a custom-built IR laser undergoing significant improvement in frequency stabilization. The results of this study demonstrate the viability of a simple, computer-controlled, non-temperature-stabilized FP locking scheme for our applications, laser cooling of Ca(+) ions, and its use in other applications with similar modest frequency stabilization requirements.

Performance of a Distributed Simultaneous Strain and Temperature Sensor Based on a Fabry-Perot Laser Diode and a Dual-Stage FBG Optical Demultiplexer

Directory of Open Access Journals (Sweden)

Shinwon Kang

2013-11-01

Full Text Available A simultaneous strain and temperature measurement method using a Fabry-Perot laser diode (FP-LD and a dual-stage fiber Bragg grating (FBG optical demultiplexer was applied to a distributed sensor system based on Brillouin optical time domain reflectometry (BOTDR. By using a Kalman filter, we improved the performance of the FP-LD based OTDR, and decreased the noise using the dual-stage FBG optical demultiplexer. Applying the two developed components to the BOTDR system and using a temperature compensating algorithm, we successfully demonstrated the simultaneous measurement of strain and temperature distributions under various experimental conditions. The observed errors in the temperature and strain measured using the developed sensing system were 0.6 °C and 50 με, and the spatial resolution was 1 m, respectively.

Tapered optical fiber tip probes based on focused ion beam-milled Fabry-Perot microcavities

Science.gov (United States)

André, Ricardo M.; Warren-Smith, Stephen C.; Becker, Martin; Dellith, Jan; Rothhardt, Manfred; Zibaii, M. I.; Latifi, H.; Marques, Manuel B.; Bartelt, Hartmut; Frazão, Orlando

2016-09-01

Focused ion beam technology is combined with dynamic chemical etching to create microcavities in tapered optical fiber tips, resulting in fiber probes for temperature and refractive index sensing. Dynamic chemical etching uses hydrofluoric acid and a syringe pump to etch standard optical fibers into cone structures called tapered fiber tips where the length, shape, and cone angle can be precisely controlled. On these tips, focused ion beam is used to mill several different types of Fabry-Perot microcavities. Two main cavity types are initially compared and then combined to form a third, complex cavity structure. In the first case, a gap is milled on the tapered fiber tip which allows the external medium to penetrate the light guiding region and thus presents sensitivity to external refractive index changes. In the second, two slots that function as mirrors are milled on the tip creating a silica cavity that is only sensitive to temperature changes. Finally, both cavities are combined on a single tapered fiber tip, resulting in a multi-cavity structure capable of discriminating between temperature and refractive index variations. This dual characterization is performed with the aid of a fast Fourier transform method to separate the contributions of each cavity and thus of temperature and refractive index. Ultimately, a tapered optical fiber tip probe with sub-standard dimensions containing a multi-cavity structure is projected, fabricated, characterized and applied as a sensing element for simultaneous temperature and refractive index discrimination.

High-energy localized eigenstates in a Fabry-Perot graphene resonator in a magnetic field

Science.gov (United States)

Zalipaev, V. V.

2012-06-01

A semiclassical analysis of the high-energy eigenstates of Dirac fermions inside a graphene monolayer nanoribbon resonator of Fabry-Perot type in a magnetic field with zigzag boundary conditions is discussed. A semiclassical asymptotic method of construction of Maslov spectral series of energy spectrum and eigenfunctions, localized in an asymptotically small neighborhood of a periodic orbit, is developed for the graphene Dirac system. The isolated periodic orbit is confined between two flat boundaries. The analysis involves constructing a localized asymptotic solution to the Dirac system (electron-hole Gaussian beam). Then, the stability of a continuous family of periodic orbits (POs) confined between reflecting boundaries of the resonator is studied. The asymptotics of the eigenfunctions are constructed as a superposition of two Gaussian beams propagating in opposite directions between two reflecting points of the periodic orbit. The asymptotics of the energy spectrum are obtained by means of the generalized Bohr-Sommerfeld quantization condition only for stable POs. It provides two parts of semiclassical Maslov spectral series with positive and negative energies, for electrons and holes, correspondingly, with two different Hamiltonian dynamics and families of classical trajectories. The presence of electrostatic potential is vital as it makes a family of periodic orbit stable. For one subclass of lens-shaped periodic orbits, for a piecewise linear potential, localized eigenstates were computed numerically by the finite element method using COMSOL, and proved to be in very good agreement with the ones computed semiclassically.

Department of Defense Intelligence Information System (DoDIIS). Instructions 2000

Science.gov (United States)

2000-02-01

Specification (I&RTS). DC6 Every DoDIIS site shall complete the transition of its installed computing and processing base to the DII COE standards and... and processing base to the DII COE standards and protocols by the date specified in the DoDIIS Calendar. General segmentation guidelines are as follows...defined in the DII COE Integration and Runtime Specification (I&RTS). DC6 Every DoDIIS site shall complete the transition of its installed computing

An efficient hexagonal switched beam antenna structure based on Fabry-Perot cavity leaky-wave antenna

Science.gov (United States)

Aymen El Cafsi, Mohamed; Nedil, Mourad; Osman, Lotfi; Gharsallah, Ali

2015-11-01

A novel design of switched beam antenna (SBA) system based on Fabry-Perot cavity leaky-wave antenna (FPC LWA) is designed and fabricated for base station operating in the unlicensed ISM central frequency band at 5.8 GHz of the wireless local area network (WLAN) standard. The proposed SBA is designed with hexagonal shape of FPC LWA Arrays in order to get 360° of coverage. The single element of FPC LWA array is composed of a patch antenna and covered by a Partially Reflective Surface (PRS), which is composed of a Metal Strip Grating and printed on a high permittivity Superstrate. First, the Transmission Line Model of FPC LWA is introduced to analyse and calculate the far-field components in E- and H planes by using the Transverse Equivalent Network. This approach is then compared with other full wave's commercial software such as Ansoft HFSS and CST Microwave Studio. Second, a parametric study is performed to evaluate the effect of the angle formed by the two successive FPC LWA on the radiation efficiency of the activate sector. To examine the performance of the proposed SBA, experimental prototype was fabricated and measured. As a result, multiple orthogonal beams (six beams) of 10 dBi of gain with low Side Lobes Level and 360° of coverage are produced. This SBA structure is suitable for WLAN communication systems.

Room-Temperature Pressure-Induced Optically-Actuated Fabry-Perot Nanomechanical Resonator with Multilayer Graphene Diaphragm in Air

Directory of Open Access Journals (Sweden)

Cheng Li

2017-11-01

Full Text Available We demonstrated a miniature and in situ ~13-layer graphene nanomechanical resonator by utilizing a simple optical fiber Fabry-Perot (F-P interferometric excitation and detection scheme. The graphene film was transferred onto the endface of a ferrule with a 125-μm inner diameter. In contrast to the pre-tension induced in membrane that increased quality (Q factor to ~18.5 from ~3.23 at room temperature and normal pressure, the limited effects of air damping on resonance behaviors at 10−2 and 105 Pa were demonstrated by characterizing graphene F-P resonators with open and micro-air-gap cavities. Then in terms of optomechanical behaviors of the resonator with an air micro-cavity configuration using a polished ferrule substrate, measured resonance frequencies were increased to the range of 509–542 kHz from several kHz with a maximum Q factor of 16.6 despite the lower Knudsen number ranging from 0.0002 to 0.0006 in damping air over a relative pressure range of 0–199 kPa. However, there was the little dependence of Q on resonance frequency. Note that compared with the inferior F-P cavity length response to applied pressures due to interfacial air leakage, the developed F-P resonator exhibited a consistent fitted pressure sensitivity of 1.18 × 105 kHz3/kPa with a good linearity error of 5.16% in the tested range. These measurements shed light on the pre-stress-dominated pressure-sensitive mechanisms behind air damping in in situ F-P resonant sensors using graphene or other 2D nanomaterials.

Micro Extrinsic Fiber-Optic Fabry-Perot Interferometric Sensor Based on Erbium- and Boron-Doped Fibers

International Nuclear Information System (INIS)

Yun-Jiang, Rao; Bing, Xu; Zeng-Ling, Ran; Yuan, Gong

2010-01-01

Micro extrinsic Fabry–Perot interferometers (MEFPIs), with cavity lengths of up to ∼ 9 μm and maximum fringe contrast of ∼ 19 dB, are fabricated by chemically etching Er- and B-doped optical fibers and then splicing the etched fiber to a single-mode fiber, for the first time to the best of our knowledge. The strain and temperature responses of the MEFPI sensors are investigated experimentally. Good linearity and high sensitivity are achieved. Such a type of MEFPI sensor is cost-effective and suitable for mass production, indicating its great potential for a wide range of applications. (fundamental areas of phenomenology(including applications))

Theoretical and experimental study of low-finesse extrinsic Fabry-Perot interferometric fiber optic sensors

Science.gov (United States)

Han, Ming

In this dissertation, detailed and systematic theoretical and experimental study of low-finesse extrinsic Fabry-Perot interferometric (EFPI) fiber optic sensors together with their signal processing methods for white-light systems are presented. The work aims to provide a better understanding of the operational principle of EFPI fiber optic sensors, and is useful and important in the design, optimization, fabrication and application of single mode fiber(SMF) EFPI (SMF-EFPI) and multimode fiber (MMF) EFPI (MMF-EFPI) sensor systems. The cases for SMF-EFPI and MMF-EFPI sensors are separately considered. In the analysis of SMF-EFPI sensors, the light transmitted in the fiber is approximated by a Gaussian beam and the obtained spectral transfer function of the sensors includes an extra phase shift due to the light coupling in the fiber end-face. This extra phase shift has not been addressed by previous researchers and is of great importance for high accuracy and high resolution signal processing of white-light SMF-EFPI systems. Fringe visibility degradation due to gap-length increase and sensor imperfections is studied. The results indicate that the fringe visibility of a SMF-EFPI sensor is relatively insensitive to the gap-length change and sensor imperfections. Based on the spectral fringe pattern predicated by the theory of SMF-EFPI sensors, a novel curve fitting signal processing method (Type 1 curve-fitting method) is presented for white-light SMF-EFPI sensor systems. Other spectral domain signal processing methods including the wavelength-tracking, the Type 2-3 curve fitting, Fourier transform, and two-point interrogation methods are reviewed and systematically analyzed. Experiments were carried out to compare the performances of these signal processing methods. The results have shown that the Type 1 curve fitting method achieves high accuracy, high resolution, large dynamic range, and the capability of absolute measurement at the same time, while others either

An MRI-Guided Telesurgery System Using a Fabry-Perot Interferometry Force Sensor and a Pneumatic Haptic Device.

Science.gov (United States)

Su, Hao; Shang, Weijian; Li, Gang; Patel, Niravkumar; Fischer, Gregory S

2017-08-01

This paper presents a surgical master-slave teleoperation system for percutaneous interventional procedures under continuous magnetic resonance imaging (MRI) guidance. The slave robot consists of a piezoelectrically actuated 6-degree-of-freedom (DOF) robot for needle placement with an integrated fiber optic force sensor (1-DOF axial force measurement) using the Fabry-Perot interferometry (FPI) sensing principle; it is configured to operate inside the bore of the MRI scanner during imaging. By leveraging the advantages of pneumatic and piezoelectric actuation in force and position control respectively, we have designed a pneumatically actuated master robot (haptic device) with strain gauge based force sensing that is configured to operate the slave from within the scanner room during imaging. The slave robot follows the insertion motion of the haptic device while the haptic device displays the needle insertion force as measured by the FPI sensor. Image interference evaluation demonstrates that the telesurgery system presents a signal to noise ratio reduction of less than 17% and less than 1% geometric distortion during simultaneous robot motion and imaging. Teleoperated needle insertion and rotation experiments were performed to reach 10 targets in a soft tissue-mimicking phantom with 0.70 ± 0.35 mm Cartesian space error.

Surface stress sensor based on MEMS Fabry-Perot interferometer with high wavelength selectivity for label-free biosensing

Science.gov (United States)

Takahashi, Toshiaki; Hizawa, Takeshi; Misawa, Nobuo; Taki, Miki; Sawada, Kazuaki; Takahashi, Kazuhiro

2018-05-01

We have developed a surface stress sensor based on a microelectromechanical Fabry-Perot interferometer with high wavelength selectivity by using Au half-mirrors, for highly sensitive label-free biosensing. When the target molecule is adsorbed by the antigen-antibody reaction onto a movable membrane with a thin Au film, which acts as an upper mirror of the optical interferometer, the amount of deflection of the movable membrane deflected by the change in surface stress can be detected with high sensitivity. To improve the signal at the small membrane deflection region of this biosensor resulting in detection of low concentration molecules, by integrating 50 nm-thick Au half-mirrors, the wavelength selectivity of the optical interferometer has been successfully improved 6.6 times. Furthermore, the peak shift in the reflection spectrum due to the adsorption of bovine serum albumin (BSA) antigen with a concentration of 10 ng ml-l by the antigen-antibody reaction was spectroscopically measured on the fabricated optical interferometer, and the deflection amount of the movable membrane after 10 min treatment was 2.4 times larger than that of nonspecific adsorption with the avidin molecules. This result indicated that the proposed sensor can be used for selective detection of low-concentration target antigen molecules.

Auroral zone thermospheric dynamics using Fabry-Perot interferometric measurements of the O1 15867 K emission

International Nuclear Information System (INIS)

Sica, R.J.

1985-01-01

Forty-four nights of thermospheric neutral wind and temperature measurements were obtained from College, Alaska (65 0 invariant latitude) during solar maximum using a ground-based Fabry-Perot interferometer. When averaged by increasing geomagnetic activity, the wind exhibits two main features. First, the general flow pattern poleward and westward in the evening, changing to southward and eastward in the morning, persists with increasing activity. The flow velocity increases and the change in direction occurs earlier in magnetic local time as the geomagnetic activity increases. Second, as the activity increases, the meridional wind pattern shifts equatorward with the auroral oval. Consequently, the low geomagnetic activity average wind pattern in the north is similar to the moderate activity average pattern in the south. The average thermospheric temperature is governed by the geomagnetic activity and by the previous day's 10.7 cm solar flux. The increase in temperature with solar flux is about the same as with auroral activity (approx. = 225 0 K). The dynamical behavior on individual nights highlights the importance of local auroral substorms, which can cause large deviations from both global models and the observed averages. Coupling between the E and F regions is inferred by comparing the bulk motion of the optical aurora and the observed wind. Westward-drifting auroral forms accompany the westward evening zonal wind

Small-scale kinematic structures in ring nebulae around Wolf-Rayet stars

International Nuclear Information System (INIS)

Chu, Y.H.

1988-01-01

Four ring nebulas around galactic Wolf-Rayet stars have been observed with echelle spectrographs in the long-slit mode: NGC 2359, NGC 3199, NGC 6888, and RCW 58. The spatial resolution of these observations is seeing limited at about 1-3 arcsec, which is almost a two orders of magnitude improvement from the previous Fabry-Perot scanner observations. To avoid large geometric corrections, the slit positions were placed as close to the central stars as possible. The results show that the ejecta-type nebula RCW 58 is a clumpy shell expanding regularly at about 110 km/s, as opposed to the chaotic expansion concluded from the earlier Fabry-Perot observations. For the three windblown bubbles, NGC 2359, NGC 3199, and NGC 6888, the small-scale structures revealed in the echelle data can explain the apparently discrepant expansion velocities derived from the previous large-aperture Fabry-Perot observations. 20 references

A THz plasmonics perfect absorber and Fabry-Perot cavity mechanism (Conference Presentation)

Science.gov (United States)

Zhou, Jiangfeng; Bhattarai, Khagendra; Silva, Sinhara; Jeon, Jiyeon; Kim, Junoh; Lee, Sang Jun; Ku, Zahyun

2016-10-01

The plasmonic metamaterial perfect absorber (MPA) is a recently developed branch of metamaterial which exhibits nearly unity absorption within certain frequency range.[1-6] The optically thin MPA possesses characteristic features of angular-independence, high Q-factor and strong field localization that have inspired a wide range of applications including electromagnetic wave absorption,[3, 7, 8] spatial[6] and spectral[5] modulation of light,[9] selective thermal emission,[9] thermal detecting[10] and refractive index sensing for gas[11] and liquid[12, 13] targets. In this work, we demonstrate a MPA working at terahertz (THz) regime and characterize it using an ultrafast THz time-domain spectroscopy (THz-TDS). Our study reveal an ultra-thin Fabry-Perot cavity mechanism compared to the impedance matching mechanism widely adopted in previous study [1-6]. Our results also shows higher-order resonances when the cavities length increases. These higher order modes exhibits much larger Q-factor that can benefit potential sensing and imaging applications. [1] C. M. Watts, X. L. Liu, and W. J. Padilla, "Metamaterial Electromagnetic Wave Absorbers," Advanced Materials, vol. 24, pp. 98-120, Jun 19 2012. [2] M. Hedayati, F. Faupel, and M. Elbahri, "Review of Plasmonic Nanocomposite Metamaterial Absorber," Materials, vol. 7, pp. 1221-1248, 2014. [3] N. I. Landy, S. Sajuyigbe, J. J. Mock, D. R. Smith, and W. J. Padilla, "Perfect metamaterial absorber," Physical Review Letters, vol. 100, p. 207402, May 23 2008. [4] H. R. Seren, G. R. Keiser, L. Cao, J. Zhang, A. C. Strikwerda, K. Fan, et al., "Optically Modulated Multiband Terahertz Perfect Absorber," Advanced Optical Materials, vol. 2, pp. 1221-1226, 2014. [5] D. Shrekenhamer, J. Montoya, S. Krishna, and W. J. Padilla, "Four-Color Metamaterial Absorber THz Spatial Light Modulator," Advanced Optical Materials, vol. 1, pp. 905-909, 2013. [6] S. Savo, D. Shrekenhamer, and W. J. Padilla, "Liquid Crystal Metamaterial Absorber Spatial

Cavity enhanced interference of orthogonal modes in a birefringent medium

Science.gov (United States)

Kolluru, Kiran; Saha, Sudipta; Gupta, S. Dutta

2018-03-01

Interference of orthogonal modes in a birefringent crystal mediated by a rotator is known to lead to interesting physical effects (Solli et al., 2003). In this paper we show that additional feedback offered by a Fabry-Perot cavity (containing the birefringent crystal and the rotator) can lead to a novel strong interaction regime. Usual signatures of the strong interaction regime like the normal mode splitting and avoided crossings, sensitive to the rotator orientation, are reported. A high finesse cavity is shown to offer an optical setup for measuring small angles. The results are based on direct calculations of the cavity transmissions along with an analysis of its dispersion relation.

Intensity phase coherence in three-mode Fabry-Pacute erot lasers

International Nuclear Information System (INIS)

Nguyen, B.A.; Mandel, P.

1996-01-01

We study analytically the intensity phase coherence in a three-mode Fabry-Pacute erot laser. We consider in detail the case of a central mode with maximum gain and two side modes with smaller but equal gains. This laser is characterized by three relaxation oscillation frequencies Ω R double-prime approx-gt Ω L1 double-prime approx-gt Ω L2 double-prime . In the framework of a linearized theory, the laser dynamics is, respectively, inphased and perfectly antiphased at Ω R double-prime and Ω L2 double-prime , irrespective of the modal gains. At Ω L1 double-prime the antiphase is only partial if the side mode gains are smaller than the central mode gain. Analytic gain- and pump-dependent relations between the three frequencies and between the heights of the peaks in the power spectra at these frequencies are established. We also derive universal relations between the peaks of the power spectra of the modal and the total intensities at the same frequencies that do not involve any parameter at all. copyright 1996 The American Physical Society

Precision measurements of gas refractivity by means of a Fabry-Perot interferometer illustrated by the monitoring of radiator refractivity in the DELPHI RICH detectors

CERN Document Server

Filippas-Tassos, A; Fokitis, E; Maltezos, S; Patrinos, K

2002-01-01

With an updated, flexible, highly efficient and easily installed system we obtained accurate refractivity (n-1) values. This system is a refractometer based on a Fabry-Perot interferometer and was used to monitor the refractivity of DELPHI RICH Cherenkov radiators near the VUV region. By using a Pt-Ne spectral lamp and improved alignment and temperature control, the refractivities of C//5F//1//2 and C//4F//1 //0 have been monitored since 1996. With this light source, selected to have large coherence lengths, we can extract the refractivity at several wavelengths from one data set only. The estimated errors of the refractivity measurements are less than 1.2%, and depend on wavelength and the type of gas used. The various parameters affecting the accuracy of the refractometer are also discussed. Finally, results from special sample refractivity measurements of the liquid radiator (C//6F//1//4) in its gas phase, are presented.

Laser-diode pumped self-mode-locked praseodymium visible lasers with multi-gigahertz repetition rate.

Science.gov (United States)

Zhang, Yuxia; Yu, Haohai; Zhang, Huaijin; Di Lieto, Alberto; Tonelli, Mauro; Wang, Jiyang

2016-06-15

We demonstrate efficient laser-diode pumped multi-gigahertz (GHz) self-mode-locked praseodymium (Pr3+) visible lasers with broadband spectra from green to deep red for the first time to our knowledge. With a Pr3+-doped GdLiF4 crystal, stable self-mode-locked visible pulsed lasers at the wavelengths of 522 nm, 607 nm, 639 nm, and 720 nm have been obtained with the repetition rates of 2.8 GHz, 3.1 GHz, 3.1 GHz, and 3.0 GHz, respectively. The maximum output power was 612 mW with the slope efficiency of 46.9% at 639 nm. The mode-locking mechanism was theoretically analyzed. The stable second-harmonic mode-locking with doubled repetition frequency was also realized based on the Fabry-Perot effect formed in the laser cavity. In addition, we find that the polarization directions were turned with lasing wavelengths. This work may provide a new way for generating efficient ultrafast pulses with high- and changeable-repetition rates in the visible range.

Common mode frequency instability in internally phase-locked terahertz quantum cascade lasers.

Science.gov (United States)

Wanke, M C; Grine, A D; Fuller, C T; Nordquist, C D; Cich, M J; Reno, J L; Lee, Mark

2011-11-21

Feedback from a diode mixer integrated into a 2.8 THz quantum cascade laser (QCL) was used to phase lock the difference frequencies (DFs) among the Fabry-Perot (F-P) longitudinal modes of a QCL. Approximately 40% of the DF power was phase locked, consistent with feedback loop bandwidth of 10 kHz and phase noise bandwidth ~0.5 MHz. While the locked DF signal has ≤ 1 Hz linewidth and negligible drift over ~30 min, mixing measurements between two QCLs and between a QCL and molecular gas laser show that the common mode frequency stability is no better than a free-running QCL. © 2011 Optical Society of America

Stratospheric temperature measurement with scanning Fabry-Perot interferometer for wind retrieval from mobile Rayleigh Doppler lidar.

Science.gov (United States)

Xia, Haiyun; Dou, Xiankang; Shangguan, Mingjia; Zhao, Ruocan; Sun, Dongsong; Wang, Chong; Qiu, Jiawei; Shu, Zhifeng; Xue, Xianghui; Han, Yuli; Han, Yan

2014-09-08

Temperature detection remains challenging in the low stratosphere, where the Rayleigh integration lidar is perturbed by aerosol contamination and ozone absorption while the rotational Raman lidar is suffered from its low scattering cross section. To correct the impacts of temperature on the Rayleigh Doppler lidar, a high spectral resolution lidar (HSRL) based on cavity scanning Fabry-Perot Interferometer (FPI) is developed. By considering the effect of the laser spectral width, Doppler broadening of the molecular backscatter, divergence of the light beam and mirror defects of the FPI, a well-behaved transmission function is proved to show the principle of HSRL in detail. Analysis of the statistical error of the HSRL is carried out in the data processing. A temperature lidar using both HSRL and Rayleigh integration techniques is incorporated into the Rayleigh Doppler wind lidar. Simultaneous wind and temperature detection is carried out based on the combined system at Delhi (37.371°N, 97.374°E; 2850 m above the sea level) in Qinghai province, China. Lower Stratosphere temperature has been measured using HSRL between 18 and 50 km with temporal resolution of 2000 seconds. The statistical error of the derived temperatures is between 0.2 and 9.2 K. The temperature profile retrieved from the HSRL and wind profile from the Rayleigh Doppler lidar show good agreement with the radiosonde data. Specifically, the max temperature deviation between the HSRL and radiosonde is 4.7 K from 18 km to 36 km, and it is 2.7 K between the HSRL and Rayleigh integration lidar from 27 km to 34 km.

Distributed Feedback Laser Based on Single Crystal Perovskite

Science.gov (United States)

Sun, Shang; Xiao, Shumin; Song, Qinghai

2017-06-01

We demonstrate a single crystal perovskite based, with grating-structured photoresist on top, highly polarized distributed feedback laser. A lower laser threshold than the Fabry-Perot mode lasers from the same single crystal CH3NH3PbBr3 microplate was obtained. Single crystal CH3NH3PbBr3 microplates was synthesized with one-step solution processed precipitation method. Once the photoresist on top of the microplate was patterned with electron beam, the device was realized. This one-step fabrication process utilized the advantage of single crystal to the greatest extend. The ultra-low defect density in single crystalline microplate offer an opportunity for lower threshold lasing action compare with poly-crystal perovskite films. In the experiment, the lasing action based on the distributed feedback grating design was found with lower threshold and higher intensity than the Fabry-Perot mode lasers supported by the flat facets of the same microplate.

High time resolution measurements of the thermosphere from Fabry-Perot Interferometer measurements of atomic oxygen

Directory of Open Access Journals (Sweden)

E. A. K. Ford

2007-06-01

Full Text Available Recent advances in the performance of CCD detectors have enabled a high time resolution study of the high latitude upper thermosphere with Fabry-Perot Interferometers (FPIs to be performed. 10-s integration times were used during a campaign in April 2004 on an FPI located in northern Sweden in the auroral oval. The FPI is used to study the thermosphere by measuring the oxygen red line emission at 630.0 nm, which emits at an altitude of approximately 240 km. Previous time resolutions have been 4 min at best, due to the cycle of look directions normally observed. By using 10 s rather than 40 s integration times, and by limiting the number of full cycles in a night, high resolution measurements down to 15 s were achievable. This has allowed the maximum variability of the thermospheric winds and temperatures, and 630.0 nm emission intensities, at approximately 240 km, to be determined as a few minutes. This is a significantly greater variability than the often assumed value of 1 h or more. A Lomb-Scargle analysis of this data has shown evidence of gravity wave activity with waves with short periods. Gravity waves are an important feature of mesosphere-lower thermosphere (MLT dynamics, observed using many techniques and providing an important mechanism for energy transfer between atmospheric regions. At high latitudes gravity waves may be generated in-situ by localised auroral activity. Short period waves were detected in all four clear nights when this experiment was performed, in 630.0 nm intensities and thermospheric winds and temperatures. Waves with many periodicities were observed, from periods of several hours, down to 14 min. These waves were seen in all parameters over several nights, implying that this variability is a typical property of the thermosphere.

Index matching of TE and TM modes in organic multilayer waveguides

Science.gov (United States)

Thompson, Jonathan; Schmitzer, Heidrun; Wagner, Hans Peter

We investigate transverse electric (TE) and magnetic (TM) mode propagation in organic multilayers consisting of aluminum quinoline (Alq3) and perylenetetracarboxylic dianhydride (PTCDA). In particular, we analyze two multilayer waveguides, Alq3-PTCDA-Alq3 and PTCDA-Alq3-PTCDA, engineered to give index matching according to modeling. The waveguides were grown on a glass substrate via organic molecular beam deposition. Fabry-Perot oscillations observed from reflection measurements were used to confirm the individual layer thicknesses. We were able to observe refractive index matching between TE0 and TE1, as well as TE2 and TE3 modes for the PTCDA-Alq3-PTCDA waveguide due to the light propagation through the top and bottom PTCDA layers, respectively. In addition, we were able to match TE1 and TM1, as well as TE3 and TM3 modes in the Alq3-PTCDA-Alq3 multilayer due to the birefringence of the PTCDA layer. Furthermore, we are able to create mode matching for a range of wavelengths due to the similar effective refractive index dispersion of different waveguide modes. The ability to phase match different waveguide modes opens a wide range of potential applications including polarization-insensitive propagation and mode switching by adding a thin magnetic metal film within the waveguide and applying an external magnetic field.

Anterograde Tracing Method using DiI to Label Vagal Innervation of the Embryonic and Early Postnatal Mouse Gastrointestinal Tract

Science.gov (United States)

Murphy, Michelle C.; Fox, Edward A.

2007-01-01

The mouse is an extremely valuable model for studying vagal development in relation to strain differences, genetic variation, gene manipulations, or pharmacological manipulations. Therefore, a method using 1, 1′-dioctadecyl-3,3,3′,3′-tetramethylindocarbocyanine perchlorate (DiI) was developed for labeling vagal innervation of the gastrointestinal (GI) tract in embryonic and postnatal mice. DiI labeling was adapted and optimized for this purpose by varying several facets of the method. For example, insertion and crushing of DiI crystals into the nerve led to faster DiI diffusion along vagal axons and diffusion over longer distances as compared with piercing the nerve with a micropipette tip coated with dried DiI oil. Moreover, inclusion of EDTA in the fixative reduced leakage of DiI out of nerve fibers that occurred with long incubations. Also, mounting labeled tissue in PBS was superior to glycerol with n-propyl gallate, which resulted in reduced clarity of DiI labeling that may have been due to DiI leaking out of fibers. Optical sectioning of flattened wholemounts permitted examination of individual tissue layers of the GI tract wall. This procedure aided identification of nerve ending types because in most instances each type innervates a different tissue layer. Between embryonic day 12.5 and postnatal day 8, growth of axons into the GI tract, formation and patterning of fiber bundles in the myenteric plexus and early formation of putative afferent and efferent nerve terminals were observed. Thus, the DiI tracing method developed here has opened up a window for investigation during an important phase of vagal development. PMID:17418900

Study of a high finesse four mirrors Fabry Perot cavity for X-rays and Gamma rays production by laser-electron Compton scattering

International Nuclear Information System (INIS)

Fedala, Y.

2008-10-01

The main goal of this thesis is the study and design of a high finesse Fabry Perot cavity to amplify a laser beam in order to achieve power gains ranging from 10 4 to 10 5 . This cavity is dedicated to the production of intense and monochromatic X-ray for medical applications (medical RADIOTHOMX ring) and gamma rays for a Compton based polarized positron source by Compton scattering of a high power laser beam and electron beam. To increase the brightness of the Compton interaction at the collision points, it is essential to have not only a high power laser beam but also very small laser beam radii at the interaction points. To achieve such performances, 2 scenarios are possible: a concentric 2 mirrors cavity which is mechanically unstable or a 4 mirrors cavity more complex but more stable. We tested numerically mechanical stability and stability of Eigen modes polarization of various planar and non-planar geometries of 4 mirrors cavities. Experimentally, we have developed a four mirrors tetrahedral 'bow-tie' cavity; radii of the order of 20 microns were made. The Eigen modes of such a cavity, in both planar and non planar geometries, were measured and compared with the numerical results. A good agreement was observed. In a second time, the impact of Compton interaction on the transverse dynamics, in the case of the polarized positrons source, and the longitudinal dynamic, in the case of the medical ring of the electron beam was studied. Compton scattering causes energy loss and induces an additional dispersion of energy in electron beam. For the polarized positrons source, 10 collision points are planned. The transport line has been determined and the modelling of the Compton interaction effect with a simple matrix calculation was made. For the medical ring, Compton scattering causes bunch lengthening and the increase of energy dispersion which are to influence the produced X-ray flux. A study of the longitudinal dynamics of the electron beam in the ring was

Single Spatial-Mode Room-Temperature-Operated 3.0 to 3.4 micrometer Diode Lasers

Science.gov (United States)

Frez, Clifford F.; Soibel, Alexander; Belenky, Gregory; Shterengas, Leon; Kipshidze, Gela

2010-01-01

Compact, highly efficient, 3.0 to 3.4 m light emitters are in demand for spectroscopic analysis and identification of chemical substances (including methane and formaldehyde), infrared countermeasures technologies, and development of advanced infrared scene projectors. The need for these light emitters can be currently addressed either by bulky solid-state light emitters with limited power conversion efficiency, or cooled Interband Cascade (IC) semiconductor lasers. Researchers here have developed a breakthrough approach to fabrication of diode mid-IR lasers that have several advantages over IC lasers used for the Mars 2009 mission. This breakthrough is due to a novel design utilizing the strain-engineered quantum-well (QW) active region and quinternary barriers, and due to optimization of device material composition and growth conditions (growth temperatures and rates). However, in their present form, these GaSb-based laser diodes cannot be directly used as a part of sensor systems. The device spectrum is too broad to perform spectroscopic analysis of gas species, and operating currents and voltages are too high. In the current work, the emitters were fabricated as narrow-ridge waveguide index-guided lasers rather than broad stripe-gain guided multimode Fabry-Perot (FP) lasers as was done previously. These narrow-ridge waveguide mid-IR lasers exhibit much lower power consumptions, and can operate in a single spatial mode that is necessary for demonstration of single-mode distributed feedback (DBF) devices for spectroscopic applications. These lasers will enable a new generation of compact, tunable diode laser spectrometers with lower power consumption, reduced complexity, and significantly reduced development costs. These lasers can be used for the detection of HCN, C2H2, methane, and ethane.

Mid-latitude thermospheric wind changes during the St. Patrick's Day storm of 2015 observed by two Fabry-Perot interferometers in China

Science.gov (United States)

Huang, Cong; Xu, Ji-Yao; Zhang, Xiao-Xin; Liu, Dan-Dan; Yuan, Wei; Jiang, Guo-Ying

2018-04-01

In this work, we utilize thermospheric wind observations by the Fabry-Perot interferometers (FPI) from the Kelan (KL) station (38.7°N, 111.6°E, Magnetic Latitude: 28.9°N) and the Xinglong (XL) station (40.2°N, 117.4°E, Magnetic Latitude: 30.5°N) in central China during the St. Patrick's Day storm (from Mar. 17 to Mar. 19) of 2015 to analyze thermospheric wind disturbances and compare observations with the Horizontal Wind Model 2007 (HWM07). The results reveal that the wind measurements at KL show very similar trends to those at XL. Large enhancements are seen in both the westward and equatorward winds after the severe geomagnetic storm occurred. The westward wind speed increased to a peak value of 75 m/s and the equatorward wind enhanced to a peak value of over 100 m/s. There also exist obvious poleward disturbances in the meridional winds during Mar. 17 to Mar. 19. According to the comparison with HWM07, there exist evident wind speed and temporal differences between FPI-winds and the model outputs in this severe geomagnetic storm. The discrepancies between the observations and HWM07 imply that the empirical model should be used carefully in wind disturbance forecast during large geomagnetic storms and more investigations between measurements and numerical models are necessary in future studies.

1.5 W high efficiency and tunable single-longitudinal-mode Ho:YLF ring laser based on Faraday effect.

Science.gov (United States)

Wu, Jing; Ju, Youlun; Dai, Tongyu; Yao, Baoquan; Wang, Yuezhu

2017-10-30

We demonstrated an efficient and tunable single-longitudinal-mode Ho:YLF ring laser based on Faraday effect for application to measure atmospheric carbon dioxide (CO 2 ). Single-longitudinal-mode power at 2051.65 nm achieved 528 mW with the slope efficiency of 39.5% and the M 2 factor of 1.07, and the tunable range of about 178 GHz was obtained by inserting a Fabry-Perot (F-P) etalon with the thickness of 0.5 mm. In addition, the maximum single-longitudinal-mode power reached 1.5 W with the injected power of 528 mW at 2051.65 nm by master oscillator power amplifier (MOPA) technique. High efficiency and tunable single-longitudinal-mode based on Faraday effect around 2 μm has not been reported yet to the best of our knowledge.

Translation, Adaptation, and Validation of the Brazilian Version of the Dickman Impulsivity Inventory (Br-DII).

Science.gov (United States)

Gomes, Áurea K V; Diniz, Leandro F M; Lage, Guilherme M; de Miranda, Débora M; de Paula, Jonas J; Costa, Danielle; Albuquerque, Maicon R

2017-01-01

Impulsivity has mainly been described as a negative or dysfunctional characteristic associated with several disorders. However, impulsivity is not only related to dysfunctional outcomes and may explain individual differences in optimal human functioning as well. The Dickman Impulsivity Inventory (DII) is a self-report instrument measuring both the dysfunctional and the functional aspects of impulsivity. In this study, we performed the translation and cultural adaptation of the DII to the Brazilian context and analyzed its psychometric properties. Translation and cultural adaptation followed a rigorous process, which relied on an expert panel in the cross-cultural adaptation of psychological instruments. Data from 405 undergraduate students were obtained for the Brazilian version of the DII (Br-DII). The 23 items of the Br-DII was considered unsuitable according to model fit indices of the Confirmatory Factor Analysis (both for Oblique and Orthogonal models). Exploratory Factor Analysis showed an 18 items version of the Br-DII to be suitable (CFI = 0.92; TLI = 0.90, and RMSEA = 0.057). The DII's 18 items version also showed adequate Cronbach's alpha, intraclass correlation coefficient, and convergent and discriminant validity with the BIS-11. Therefore, the Br-DII demonstrated reliability and validity in the measurement of functional and dysfunctional impulsivity.

Determination of D/H Ratio on Jupiter from ISO/SWS Observations

NARCIS (Netherlands)

Lellouch, E.; Encrenaz, Th.; de Graauw, Th.; Schaeidt, S.; Feuchtgruber, H.; Beintema, D. A.; Bezard, B.; Drossart, P.; Griffin, M.; Heras, A.; Kessler, M.; Leech, K.; Morris, A.; Roelfsema, P. R.; Roos-Serote, M.; Salama, A.; Vandenbussche, B.; Valentijn, E. A.; Davies, G. R.; Naylor, D. A.

1996-01-01

Observations of Jupiter, performed on March 29, 1996, with the Short-Wavelength Spectrometer (SWS) of the Infrared Space Observatory (ISO) in Fabry-Perot mode, have allowed the first detection of the rotational R(2) line of HD at 37.7 mu m (265.3 cm(-1) ). The instrument aperture (a rectangular slit

Resonant transmission and mode modulation of acoustic waves in H-shaped metallic gratings

International Nuclear Information System (INIS)

Deng, Yu-Qiang; Fan, Ren-Hao; Zhang, Kun; Peng, Ru-Wen; Qi, Dong-Xiang

2015-01-01

In this work, we demonstrate that resonant full transmission of acoustic waves exists in subwavelength H-shaped metallic gratings, and transmission peaks can be efficiently tuned by adjusting the grating geometry. We investigate this phenomenon through both numerical simulations and theoretical calculations based on rigorous-coupled wave analysis. The transmission peaks are originated from Fabry-Perot resonances together with the couplings between the diffractive wave on the surface and the multiple guided modes in the slits. Moreover, the transmission modes can be efficiently tuned by adjusting the cavity geometry, without changing the grating thickness. The mechanism is analyzed based on an equivalent circuit model and verified by both the theoretical calculations and the numerical simulations. This research has potential application in acoustic-device miniaturization over a wide range of wavelengths

Active mode-locking of mid-infrared quantum cascade lasers with short gain recovery time.

Science.gov (United States)

Wang, Yongrui; Belyanin, Alexey

2015-02-23

We investigate the dynamics of actively modulated mid-infrared quantum cascade lasers (QCLs) using space- and time-domain simulations of coupled density matrix and Maxwell equations with resonant tunneling current taken into account. We show that it is possible to achieve active mode locking and stable generation of picosecond pulses in high performance QCLs with a vertical laser transition and a short gain recovery time by bias modulation of a short section of a monolithic Fabry-Perot cavity. In fact, active mode locking in QCLs with a short gain recovery time turns out to be more robust to the variation of parameters as compared to previously studied lasers with a long gain recovery time. We investigate the effects of spatial hole burning and phase locking on the laser output.

Statistical analysis of thermospheric gravity waves from Fabry-Perot Interferometer measurements of atomic oxygen

Directory of Open Access Journals (Sweden)

E. A. K. Ford

2008-02-01

Full Text Available Data from the Fabry-Perot Interferometers at KEOPS (Sweden, Sodankylä (Finland, and Svalbard (Norway, have been analysed for gravity wave activity on all the clear nights from 2000 to 2006. A total of 249 nights were available from KEOPS, 133 from Sodankylä and 185 from the Svalbard FPI. A Lomb-Scargle analysis was performed on each of these nights to identify the periods of any wave activity during the night. Comparisons between many nights of data allow the general characteristics of the waves that are present in the high latitude upper thermosphere to be determined. Comparisons were made between the different parameters: the atomic oxygen intensities, the thermospheric winds and temperatures, and for each parameter the distribution of frequencies of the waves was determined. No dependence on the number of waves on geomagnetic activity levels, or position in the solar cycle, was found. All the FPIs have had different detectors at various times, producing different time resolutions of the data, so comparisons between the different years, and between data from different sites, showed how the time resolution determines which waves are observed. In addition to the cutoff due to the Nyquist frequency, poor resolution observations significantly reduce the number of short-period waves (<1 h period that may be detected with confidence. The length of the dataset, which is usually determined by the length of the night, was the main factor influencing the number of long period waves (>5 h detected. Comparisons between the number of gravity waves detected at KEOPS and Sodankylä over all the seasons showed a similar proportion of waves to the number of nights used for both sites, as expected since the two sites are at similar latitudes and therefore locations with respect to the auroral oval, confirming this as a likely source region. Svalbard showed fewer waves with short periods than KEOPS data for a season when both had the same time resolution data

A preliminary study of thermosphere and mesosphere wind observed by Fabry-Perot over Kelan, China

Science.gov (United States)

Yu, Tao; Huang, Cong; Zhao, Guangxin; Mao, Tian; Wang, Yungang; Zeng, Zhongcao; Wang, Jingsong; Xia, Chunliang

2014-06-01

A Fabry-Perot interferometer (FPI) system was deployed in Kelan (38.7°N, 111.6°E), center China in November 2011, which observes the airglows at wavelengths of 892.0 nm, 557.7 nm, and 630.0 nm from OH and OI emissions in the upper atmosphere, to derive the wind and temperature at heights around 87 km, 97 km, and 250 km, respectively. From late 2011 through 2013 a series of more than 4500 measurements at each height are validated according to manufacture data quality criteria. By using these data, the morphology of wind in the mesosphere and thermosphere is investigated in this study. Preliminary results are as follows: (1) As for the diurnal variation, meridional and zonal winds at heights of 87 km and 97 km, which are derived through 892.0 nm and 557.7 nm airglows, usually range from -50 m/s to 30 m/s and -50 m/s to 50 m/s, respectively, with typical random errors of about 6-10 m/s at 87 km and 2-3 m/s at 97 km. Meridional winds usually are northward at dusk, southward at middle night, and back to northward at dawn; and zonal winds usually are eastward at dusk, westward at middle night, and back to eastward at dawn. The monthly mean winds are in good agreement with those of HWM93 results. Meridional and zonal winds at a height of 250 km, which are derived through 630.0 nm nightglow, range from -110 m/s to 80 m/s with typical random errors of about 8-10 m/s. Meridional winds usually are northward at dusk, southward at middle night, and back to northward at dawn; and zonal winds usually are eastward at dusk, zero at middle night, and westward at dawn; and they are also well consistent with HWM93 results. (2) As for the seasonal variation, meridional winds at the heights of 87 km and 97 km have a visible annual variation at 12-17 LT and with a little semiannual variation at all other hours, but the zonal winds at the heights of 87 km and 97 km have a semiannual variation all night. The seasonal dependence of the winds, both meridional and zonal winds, at the height

Fabry-Perot-like interference security image structures: From passive to active

International Nuclear Information System (INIS)

Baloukas, B.; Trottier-Lapointe, W.; Martinu, L.

2014-01-01

Counterfeiting of products and important documents is at an all-time high and is costing the world economy hundreds of billions of dollars yearly as well as posing significant safety and health hazards through the production of uncertified goods, e.g., pharmaceutical products. To limit these effects, interference-based optical security devices offering an angular color shift are still widely in use. Unfortunately, commercial iridescent materials are now readily available and represent a potential source of counterfeiting. In this short review, we first describe the basic principles behind passive interference security image structures (ISIS) and the qualities which have resulted in their integration into most important documents. Various features which have been added to ISIS in order to make them harder to duplicate yet simpler to authenticate are also presented (metamerism, magnetic materials, diffraction, etc.). We then address the implementation of active materials, mainly electrochromic WO 3 as a means of generating two-level authentication devices. Finally, we discuss some general considerations to keep in mind when developing features for security applications. - Highlights: • We review Fabry–Perot-like metal-dielectric filters used in optical security. • We discuss/demonstrate recent additions: metamerism, magnetism and diffraction. • We demonstrate a feature based on the use of thin metallic mirrors. • We cover recent developments in the use of active materials. • We demonstrate an electrochromic feature with two levels of authentication

A new microcavity design for single molecule detection

International Nuclear Information System (INIS)

Steiner, M.; Schleifenbaum, F.; Stupperich, C.; Failla, A.V.; Hartschuh, A.; Meixner, A.J.

2006-01-01

We present a new microcavity design which allows for efficient detection of single molecules by measuring the molecular fluorescence emission coupled into a resonant cavity mode. The Fabry-Perot-type microresonator consists of two silver mirrors separated by a thin polymer film doped with dye molecules in ultralow concenctration. By slightly tilting one of the mirrors different cavity lengths can be selected within the same sample. Locally, on a μm scale, the microcavity still acts as a planar Fabry-Perot resonator. Using scanning confocal fluorescence microscopy, single emitters on resonance with a single mode of the microresonator can be spatially addressed. Our microcavity is demonstrated to be well-suited for investigating the coupling mechanism between single quantum emitters and single modes of the electromagnetic field. The microcavity layout could be integrated in a lab-on-a-microchip design for ultrasensitive microfluidic analytics and can be considered as an important improvement for single photon sources based on single molecules operating at room temperature

Electrically tunable Fabry-Péerot resonator based on microstructured Si containing liquid crystal

KAUST Repository

Tolmachev, Vladimir A.; Melnikov, Vasily; Baldycheva, Anna V.; Berwick, Kevin; Perova, Tatiana S.

2012-01-01

We have built Fabry-Perot resonators based on microstructured silicon and a liquid crystal. The devices exhibit tuning of the resonance peaks over a wide range, with relative spectral shifts of up to Delta lambda/lambda = 10%. In order to achieve this substantial spectral shift, cavity peaks of high order were used. Under applied voltages of up to 15 V, a variation in the refractive index of the nematic liquid crystal E7 from Delta n(LC) = 0.12 to Delta n(LC) = 0.17 was observed. These results may have practical applications in the near-, mid and far-infrared range.

Fabry-Perot-like interference security image structures: From passive to active

Energy Technology Data Exchange (ETDEWEB)

Baloukas, B., E-mail: bill.baloukas@polymtl.ca; Trottier-Lapointe, W.; Martinu, L., E-mail: ludvik.martinu@polymtl.ca

2014-05-30

Counterfeiting of products and important documents is at an all-time high and is costing the world economy hundreds of billions of dollars yearly as well as posing significant safety and health hazards through the production of uncertified goods, e.g., pharmaceutical products. To limit these effects, interference-based optical security devices offering an angular color shift are still widely in use. Unfortunately, commercial iridescent materials are now readily available and represent a potential source of counterfeiting. In this short review, we first describe the basic principles behind passive interference security image structures (ISIS) and the qualities which have resulted in their integration into most important documents. Various features which have been added to ISIS in order to make them harder to duplicate yet simpler to authenticate are also presented (metamerism, magnetic materials, diffraction, etc.). We then address the implementation of active materials, mainly electrochromic WO{sub 3} as a means of generating two-level authentication devices. Finally, we discuss some general considerations to keep in mind when developing features for security applications. - Highlights: • We review Fabry–Perot-like metal-dielectric filters used in optical security. • We discuss/demonstrate recent additions: metamerism, magnetism and diffraction. • We demonstrate a feature based on the use of thin metallic mirrors. • We cover recent developments in the use of active materials. • We demonstrate an electrochromic feature with two levels of authentication.

A tunable and switchable single-longitudinal-mode dual-wavelength fiber laser with a simple linear cavity.

Science.gov (United States)

He, Xiaoying; Fang, Xia; Liao, Changrui; Wang, D N; Sun, Junqiang

2009-11-23

A simple linear cavity erbium-doped fiber laser based on a Fabry-Perot filter which consists of a pair of fiber Bragg gratings is proposed for tunable and switchable single-longitudinal-mode dual-wavelength operation. The single-longitudinal-mode is obtained by the saturable absorption of an unpumed erbium-doped fiber together with a narrow-band fiber Bragg grating. Under the high pump power (>166 mW) condition, the stable dual-wavelength oscillation with uniform amplitude can be realized by carefully adjusting the polarization controller in the cavity. Wavelength selection and switching are achieved by tuning the narrow-band fiber Bragg grating in the system. The spacing of the dual-wavelength can be selected at 0.20 nm (approximately 25.62 GHz), 0.22 nm (approximately 28.19 GHz) and 0.54 nm (approximately 69.19 GHz).

GHz-bandwidth upconversion detector using a unidirectional ring cavity to reduce multilongitudinal mode pump effects

DEFF Research Database (Denmark)

Meng, Lichun; Høgstedt, Lasse; Tidemand-Lichtenberg, Peter

2017-01-01

We demonstrate efficient upconversion of modulated infrared (IR) signals over a wide bandwidth (up to frequencies in excess of 1 GHz) via cavity-enhanced sum-frequency generation (SFG) in a periodically poled LiNbO3. Intensity modulated IR signal is produced by combining beams from two 1547 nm...... narrow-linewidth lasers in a fiber coupler while tuning their wavelength difference down to 10 pm or less. The SFG crystal is placed inside an Nd:YVO4 ring cavity that provides 1064 nm circulating pump powers of up to 150 W in unidirectional operation. Measured Fabry-Perot spectrum at 1064 nm confirms...... the enhanced spectral stability from multiple to single longitudinal mode pumping condition. We describe analytically and demonstrate experimentally the deleterious effects of using a multimode pump to the high-bandwidth RF spectrum of the 630 nm SFG output. Offering enhanced sensitivity without the need...

FIR and sub-mm direct detection spectrometers for spaceborne astronomy

Science.gov (United States)

Wijnbergen, Jan J.; de Graauw, Thijs

1990-12-01

Candidate spaceborne sub-mm instrumentation proposed for space projects with large passively cooled telescopes are reviewed. Grating instruments and Fourier transform spectroscopy (FTS) spectrometers are discussed. Particular attention is given to imaging Fabry-Perot spectrometers. The special needs of the Large Deployable Reflector (LDR) and for the Far InfraRed Space Telescope (FIRST) missions in this area are outlined. Possible Fabry-Perot spectrometer setups are diagrammed and outlined. The use of spherical and multiplex Fabry-Perot spectrometers is discussed.

Normal mode splitting and ground state cooling in a Fabry—Perot optical cavity and transmission line resonator

International Nuclear Information System (INIS)

Chen Hua-Jun; Mi Xian-Wu

2011-01-01

Optomechanical dynamics in two systems which are a transmission line resonator and Fabrya—Perot optical cavity via radiation—pressure are investigated by linearized quantum Langevin equation. We work in the resolved sideband regime where the oscillator resonance frequency exceeds the cavity linewidth. Normal mode splittings of the mechanical resonator as a pure result of the coupling interaction in the two optomechanical systems is studied, and we make a comparison of normal mode splitting of mechanical resonator between the two systems. In the optical cavity, the normal mode splitting of the movable mirror approaches the latest experiment very well. In addition, an approximation scheme is introduced to demonstrate the ground state cooling, and we make a comparison of cooling between the two systems dominated by two key factors, which are the initial bath temperature and the mechanical quality factor. Since both the normal mode splitting and cooling require working in the resolved sideband regime, whether the normal mode splitting influences the cooling of the mirror is considered. Considering the size of the mechanical resonator and precooling the system, the mechanical resonator in the transmission line resonator system is easier to achieve the ground state cooling than in optical cavity. (electromagnetism, optics, acoustics, heat transfer, classical mechanics, and fluid dynamics)

Toluidine blue-O is a Nissl bright-field counterstain for lipophilic fluorescent tracers Di-ASP, DiI and DiO.

Science.gov (United States)

Chelvanayagam, D K; Beazley, L D

1997-03-01

The stain toluidine blue-O (tol blue), applied to sections of neural tissue, is shown to be compatible with the vivid fluorescent lipophilic neural tracers 4-(4-dihexadecylaminostyryl)-N-methylpyridinium iodide (Di-ASP), 3,3'-dioctadecyloxacarbocyanine perchlorate (DiO) and 1,1'-dioctadecyl-3,3,3',3'-tetramethylindocarbocyanine perchlorate (DiI). As with other Nissl stains, toluidine blue-O fluoresces in the red end of the spectrum but such fluorescence quenches upon binding with tissue. Moreover, progressive staining occurs at concentrations low enough to minimise any background fluorescence attributable to non-specific residence of the stain. The bright yellow Di-ASP and vivid green DiO signals are spectrally removed from the red fluorescence of toluidine blue-O. With toluidine blue-O counterstaining, Di-ASP generally offers contrast superior to that with DiI, however, the latter is improved by viewing in a polarised green bright field. Visible Di-ASP emission, although broad, peaks at a more film-sensitive region of the spectrum than that for DiI, thus reducing the photographic exposure required.

Interferometric filters for spectral discrimination in high-spectral-resolution lidar: performance comparisons between Fabry-Perot interferometer and field-widened Michelson interferometer.

Science.gov (United States)

Cheng, Zhongtao; Liu, Dong; Yang, Yongying; Yang, Liming; Huang, Hanlu

2013-11-10

Thanks to wavelength flexibility, interferometric filters such as Fabry-Perot interferometers (FPIs) and field-widened Michelson interferometers (FWMIs) have shown great convenience for spectrally separating the molecule and aerosol scattering components in the high-spectral-resolution lidar (HSRL) return signal. In this paper, performance comparisons between the FPI and FWMI as a spectroscopic discrimination filter in HSRL are performed. We first present a theoretical method for spectral transmission analysis and quantitative evaluation on the spectral discrimination. Then the process in determining the parameters of the FPI and FWMI for the performance comparisons is described. The influences from the incident field of view (FOV), the cumulative wavefront error induced by practical imperfections, and the frequency locking error on the spectral discrimination performance of the two filters are discussed in detail. Quantitative analyses demonstrate that FPI can produce higher transmittance while the remarkable spectral discrimination is one of the most appealing advantages of FWMI. As a result of the field-widened design, the FWMI still performs well even under the illumination with large FOV while the FPI is only qualified for a small incident angle. The cumulative wavefront error attaches a great effect on the spectral discrimination performance of the interferometric filters. We suggest if a cumulative wavefront error is less than 0.05 waves RMS, it is beneficial to employ the FWMI; otherwise, FPI may be more proper. Although the FWMI shows much more sensitivity to the frequency locking error, it can outperform the FPI given a locking error less than 0.1 GHz is achieved. In summary, the FWMI is very competent in HSRL applications if these practical engineering and control problems can be solved, theoretically. Some other estimations neglected in this paper can also be carried out through the analytical method illustrated herein.

A line-of-sight electron cyclotron emission receiver for electron cyclotron resonance heating feedback control of tearing modes

DEFF Research Database (Denmark)

Oosterbeek, J.W.; Bürger, A.; Westerhof, E.

2008-01-01

An electron cyclotron emission (ECE) receiver inside the electron cyclotron resonance heating (ECRH) transmission line has been brought into operation. The ECE is extracted by placing a quartz plate acting as a Fabry-Perot interferometer under an angle inside the electron cyclotron wave (ECW) bea...

Distributed dual-parameter optical fiber sensor based on cascaded microfiber Fabry-Pérot interferometers

Science.gov (United States)

Xiang, Yang; Luo, Yiyang; Zhang, Wei; Liu, Deming; Sun, Qizhen

2017-04-01

We propose and demonstrate a distributed fiber sensor based on cascaded microfiber Fabry-Perot interferometers (MFPI) for simultaneous refractive index (SRI) and temperature measurement. By employing MFPI which is fabricated by taper-drawing the center of a uniform fiber Bragg grating (FBG) on standard fiber into a section of microfiber, dual parameters including SRI and temperature can be detected through demodulating the reflection spectrum of the MFPI. Further, wavelength-division-multiplexing (WDM) is applied to realize distributed dual-parameter fiber sensor by using cascaded MFPIs with different Bragg wavelengths. A prototype sensor system with 5 cascaded MFPIs is constructed to experimentally demonstrate the sensing performance.

3DII implantation effect on corrosion properties of the AISI/SAE 1020 steel

Energy Technology Data Exchange (ETDEWEB)

Dulce M., H.J.; Rueda V., Alejandro [Universidad Francisco de Paula Santander, A.A. 1055, Cucuta (Colombia); Dougar-Jabon, Valeri [Universidad Industrial de Santander, A.A. 678, Bucaramanga (Colombia)

2005-08-01

The three dimensional ion implantation technology (3DII) is one of the methods of improving the tribological characteristics and resistance to hydrogen embrittlement processes in metals. In this report, some results concerning the resistance effect of nitrogen ion implantation to oxidation of the sample, made of AISI/SAE 1020 steel, are given. The nitrogen ions were implanted in the discharge chamber of the JUPITER reactor. Both the treated and untreated samples were tested through potential-static measurements, which permitted to determine the corrosion current, the slopes that characterise the braking level of anode and cathode reactions. The polarization resistance near the corrosion potential is calculated. The results of the study encourage to consider the nitrogen ion implantation in high voltage and low pressure discharges as one of the methods of anticorrosive protection which do not change the geometric configuration of the treated steel pieces. (copyright 2005 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

The Feasibility of Tropospheric and Total Ozone Determination Using a Fabry-perot Interferometer as a Satellite-based Nadir-viewing Atmospheric Sensor. Ph.D. Thesis

Science.gov (United States)

Larar, Allen Maurice

1993-01-01

Monitoring of the global distribution of tropospheric ozone (O3) is desirable for enhanced scientific understanding as well as to potentially lessen the ill-health impacts associated with exposure to elevated concentrations in the lower atmosphere. Such a capability can be achieved using a satellite-based device making high spectral resolution measurements with high signal-to-noise ratios; this would enable observation in the pressure-broadened wings of strong O3 lines while minimizing the impact of undesirable signal contributions associated with, for example, the terrestrial surface, interfering species, and clouds. The Fabry-Perot Interferometer (FPI) provides high spectral resolution and high throughput capabilities that are essential for this measurement task. Through proper selection of channel spectral regions, the FPI optimized for tropospheric O3 measurements can simultaneously observe a stratospheric component and thus the total O3 column abundance. Decreasing stratospheric O3 concentrations may lead to an increase in biologically harmful solar ultraviolet radiation reaching the earth's surface, which is detrimental to health. In this research, a conceptual instrument design to achieve the desired measurement has been formulated. This involves a double-etalon fixed-gap series configuration FPI along with an ultra-narrow bandpass filter to achieve single-order operation with an overall spectral resolution of approximately .068 cm(exp -1). A spectral region of about 1 cm(exp -1) wide centered at 1054.73 cm(exp -1) within the strong 9.6 micron ozone infrared band is sampled with 24 spectral channels. Other design characteristics include operation from a nadir-viewing satellite configuration utilizing a 9 inch (diameter) telescope and achieving horizontal spatial resolution with a 50 km nadir footprint. A retrieval technique has been implemented and is demonstrated for a tropical atmosphere possessing enhanced tropospheric ozone amounts. An error analysis

Bidirectional lipid droplet velocities are controlled by differential binding strengths of HCV core DII protein.

Directory of Open Access Journals (Sweden)

Rodney K Lyn

Full Text Available Host cell lipid droplets (LD are essential in the hepatitis C virus (HCV life cycle and are targeted by the viral capsid core protein. Core-coated LDs accumulate in the perinuclear region and facilitate viral particle assembly, but it is unclear how mobility of these LDs is directed by core. Herein we used two-photon fluorescence, differential interference contrast imaging, and coherent anti-Stokes Raman scattering microscopies, to reveal novel core-mediated changes to LD dynamics. Expression of core protein's lipid binding domain II (DII-core induced slower LD speeds, but did not affect directionality of movement on microtubules. Modulating the LD binding strength of DII-core further impacted LD mobility, revealing the temporal effects of LD-bound DII-core. These results for DII-core coated LDs support a model for core-mediated LD localization that involves core slowing down the rate of movement of LDs until localization at the perinuclear region is accomplished where LD movement ceases. The guided localization of LDs by HCV core protein not only is essential to the viral life cycle but also poses an interesting target for the development of antiviral strategies against HCV.

Repetitively Mode-Locked Cavity-Enhanced Absorption Spectroscopy (RML-CEAS for Near-Infrared Gas Sensing

Directory of Open Access Journals (Sweden)

Qixin He

2017-12-01

Full Text Available A Pound-Drever-Hall (PDH-based mode-locked cavity-enhanced sensor system was developed using a distributed feedback diode laser centered at 1.53 µm as the laser source. Laser temperature scanning, bias control of the piezoelectric ceramic transducer (PZT and proportional-integral-derivative (PID feedback control of diode laser current were used to repetitively lock the laser modes to the cavity modes. A gas absorption spectrum was obtained by using a series of absorption data from the discrete mode-locked points. The 15 cm-long Fabry-Perot cavity was sealed using an enclosure with an inlet and outlet for gas pumping and a PZT for cavity length tuning. The performance of the sensor system was evaluated by conducting water vapor measurements. A linear relationship was observed between the measured absorption signal amplitude and the H2O concentration. A minimum detectable absorption coefficient of 1.5 × 10–8 cm–1 was achieved with an averaging time of 700 s. This technique can also be used for the detection of other trace gas species by targeting the corresponding gas absorption line.

Frequency splitting of polarization eigenmodes in microscopic Fabry–Perot cavities

International Nuclear Information System (INIS)

Uphoff, Manuel; Brekenfeld, Manuel; Rempe, Gerhard; Ritter, Stephan

2015-01-01

We study the frequency splitting of the polarization eigenmodes of the fundamental transverse mode in CO 2 laser-machined, high-finesse optical Fabry–Perot cavities and investigate the influence of the geometry of the cavity mirrors. Their highly reflective surfaces are typically not rotationally symmetric but have slightly different radii of curvature along two principal axes. We observe that the eccentricity of such elliptical mirrors lifts the degeneracy of the polarization eigenmodes. The impact of the eccentricity increases for smaller radii of curvature. A model derived from corrections to the paraxial resonator theory is in excellent agreement with the measurements, showing that geometric effects are the main source of the frequency splitting of polarization modes for the type of microscopic cavity studied here. By rotating one of the mirrors around the cavity axis, the splitting can be tuned. In the case of an identical differential phase shift per mirror, it can even be eliminated, despite a nonvanishing eccentricity of each mirror. We expect our results to have important implications for many experiments in cavity quantum electrodynamics, where Fabry–Perot cavities with small mode volumes are required. (paper)

Optical fibre sensing in metals by embedment in 3D printed metallic structures

Science.gov (United States)

Maier, R. R. J.; Havermann, D.; Schneller, O.; Mathew, J.; Polyzos, D.; MacPherson, W. N.; Hand, D. P.

2014-05-01

Additive manufacturing or 3D printing of structural components in metals has potential to revolutionise the manufacturing industry. Embedded sensing in such structures opens a route towards SMART metals, providing added functionality, intelligence and enhanced performance in many components. Such embedded sensors would be capable of operating at extremely high temperatures by utilizing regenerated fibre Bragg gratings and in-fibre Fabry-Perot cavities.

Lineshape-asymmetry elimination in weak atomic transitions driven by an intense standing wave field

Science.gov (United States)

Antypas, Dionysios; Fabricant, Anne; Budker, Dmitry

2018-05-01

Owing to the ac-Stark effect, the lineshape of a weak optical transition in an atomic beam can become significantly distorted, when driven by an intense standing wave field. We use an Yb atomic beam to study the lineshape of the 6s2 1S0 -> 5d6s 3D1 transition, which is excited with light circulating in a Fabry-Perot resonator. We demonstrate two methods to avoid the distortion of the transition profile. Of these, one relies on the operation of the resonator in multiple longitudinal modes, and the other in multiple transverse modes.

Fabry Disease

Science.gov (United States)

... SEARCH Definition Treatment Prognosis Clinical Trials Organizations Publications Definition Fabry disease is caused by the lack of or faulty ... severe symptoms similar to males with the disorder. × Definition Fabry disease is caused by the lack of or faulty ...

Experimental study on the safety of Kyoto University Research Reactor at natural circulation cooling mode

International Nuclear Information System (INIS)

Zhang, Jian; Shen, Xiuzhong; Fujihara, Yasuyuki; Sano, Tadafumi; Yamamoto, Toshihiro; Nakajima, Ken

2015-01-01

Highlights: • The natural circulation cooling capacity of Kyoto University Research Reactor (KUR) was experimentally investigated. • The distributions of the outlet temperature of the fuel elements under natural circulation operations were measured. • The average temperature rise and the average natural circulation flow velocity in core were calculated. • The safety of KUR under all of the normal operations with natural circulation cooling mode has been analyzed. • The natural circulation flow after the reactor shutdown was confirmed. - Abstract: In this study, the natural circulation cooling capacity of Kyoto University Research Reactor (KUR) is experimentally investigated by measuring the inlet and outlet temperatures of the core under natural circulation operation at various thermal powers ranging from 10 kW to 100 kW and the shutdown state. In view of the uneven power distribution and the resultant inconsistent coolant outlet temperature in the core, eight measuring points located separately in the outlet of the fuel elements were chosen to investigate the distribution of the outlet temperature of the core. The natural circulation cooling capacity represented by the average natural circulation flow velocity in the core is calculated from the temperature difference between the outlet and inlet temperature of the core. The measured outlet temperature of the fuel elements shows a cross-sectional distribution agreeing with the distribution of the thermal output of the fuel elements in the core. Since the measured outlet temperatures decrease quickly in the flow direction in a small local region above the outlet of the core, the mixing of the hot water out of the core with the cold water around the core outlet is found to happen in the small region not more than 5 cm far from the core outlet. The natural circulation flow velocity in the core increases non-linearly with the thermal power. The safety of KUR has been analysed by conservatively estimating the

The Kyoto protocol development; La viabilite du protocole de Kyoto

Energy Technology Data Exchange (ETDEWEB)

Cooper, R. [Harvard Univ., Barrow, AK (United States); Guesneris, R. [College de France, 75 - Paris (France)

2002-04-01

From the author R. Cooper point of view the Kyoto Protocol is a flawed concept. The reasons for dropping Kyoto are presented in this paper insisting that rejecting Kyoto not means to imply that global climate change is not a serious problem. After a presentation of the US policy facing the Climatic Change, some concluding propositions are proposed. (A.L.B.)

Components for monolithic fiber chirped pulse amplification laser systems

Science.gov (United States)

Swan, Michael Craig

The first portion of this work develops techniques for generating femtosecond-pulses from conventional fabry-perot laser diodes using nonlinear-spectral-broadening techniques in Yb-doped positive dispersion fiber ampliers. The approach employed an injection-locked fabry-perot laser diode followed by two stages of nonlinear-spectral-broadening to generate sub-200fs pulses. This thesis demonstrated that a 60ps gain-switched fabry-perot laser-diode can be injection-locked to generate a single-longitudinal-mode pulse and compressed by nonlinear spectral broadening to 4ps. Two problems have been identified that must be resolved before moving forward with this approach. First, gain-switched pulses from a standard diode-laser have a number of characteristics not well suited for producing clean self-phase-modulation-broadened pulses, such as an asymmetric temporal shape, which has a long pulse tail. Second, though parabolic pulse formation occurs for any arbitrary temporal input pulse profile, deviation from the optimum parabolic input results in extensively spectrally modulated self-phase-modulation-broadened pulses. In conclusion, the approach of generating self-phase-modulation-broadened pulses from pulsed laser diodes has to be modified from the initial approach explored in this thesis. The first Yb-doped chirally-coupled-core ber based systems are demonstrated and characterized in the second portion of this work. Robust single-mode performance independent of excitation or any other external mode management techniques have been demonstrated in Yb-doped chirally-coupled-core fibers. Gain and power efficiency characteristics are not compromised in any way in this novel fiber structure up to the 87W maximum power achieved. Both the small signal gain at 1064nm of 30.3dB, and the wavelength dependence of the small signal gain were comparable to currently deployed large-mode-area-fiber technology. The efficiencies of the laser and amplifier were measured to be 75% and 54

On the equivalence of LIST and DIIS methods for convergence acceleration

Energy Technology Data Exchange (ETDEWEB)

Garza, Alejandro J. [Department of Chemistry, Rice University, Houston, Texas 77251-1892 (United States); Scuseria, Gustavo E. [Department of Chemistry and Department of Physics and Astronomy, Rice University, Houston, Texas 77251-1892, USA and Chemistry Department, Faculty of Science, King Abdulaziz University, Jeddah 21589 (Saudi Arabia)

2015-04-28

Self-consistent field extrapolation methods play a pivotal role in quantum chemistry and electronic structure theory. We, here, demonstrate the mathematical equivalence between the recently proposed family of LIST methods [Wang et al., J. Chem. Phys. 134, 241103 (2011); Y. K. Chen and Y. A. Wang, J. Chem. Theory Comput. 7, 3045 (2011)] and the general form of Pulay’s DIIS [Chem. Phys. Lett. 73, 393 (1980); J. Comput. Chem. 3, 556 (1982)] with specific error vectors. Our results also explain the differences in performance among the various LIST methods.

Multi-event study of high-latitude thermospheric wind variations at substorm onset with a Fabry-Perot interferometer at Tromsoe, Norway

Science.gov (United States)

Xu, H.; Shiokawa, K.; Oyama, S. I.; Otsuka, Y.

2017-12-01

We studied the high-latitude thermospheric wind variations near the onset time of isolated substorms. Substorm-related energy input from the magnetosphere to the polar ionosphere modifies the high-latitude ionosphere and thermosphere. For the first time, this study showed the characteristics of high-latitude thermospheric wind variations at the substorm onset. We also investigated the possibility of these wind variations as a potential trigger of substorm onset by modifying the ionospheric current system (Kan, 1993). A Fabry-Perot interferometer (FPI) at Tromsoe, Norway provided wind measurements estimated from Doppler shift of both red-line (630.0 nm for the F region) and green-line (557.7 nm for the E region) emissions of aurora and airglow. We used seven-year data sets obtained from 2009 to 2015 with a time resolution of 13 min. We first identified the onset times of local isolated substorms using ground-based magnetometer data obtained at the Tromsoe and Bear Island stations, which belongs to the IMAGE magnetometer chain. We obtained 4 red-line events and 5 green-line events taken place at different local times. For all these events, the peak locations of westward ionospheric currents identified by the ground-based magnetometer chain were located at the poleward side of Tromsoe. Then, we calculated two weighted averages of wind velocities for 30 min around the onset time and 30 min after the onset time of substorms. We evaluated differences between these two weighted averages to estimate the strength of wind changes. The observed wind changes at these substorm onsets were less than 49 m/s (26 m/s) for red-line (green-line) events, which are much smaller than the typical plasma convection speed. This indicates that the plasma motion caused by substorm-induced thermospheric winds through ion-neutral collisions is a minor effect as the driver of high-latitude plasma convection, as well as the triggering of substorm onset. We discuss possible causes of these

Waveguide resonance mode response of stacked structures of metallic sub-wavelength slit arrays

Science.gov (United States)

Tokuda, Yasunori; Takano, Keisuke; Sakaguchi, Koichiro; Kato, Kosaku; Nakajima, Makoto; Akiyama, Koichi

2018-05-01

Detailed measurements of the optical properties of two-tier systems composed of metallic plates perforated with periodic sub-wavelength slit patterns were carried out using terahertz time-domain spectroscopy. We demonstrate that the transmission properties observed experimentally for various configurations can be reproduced successfully by simulations based on the finite-differential time-domain method. Fabry-Perot-like waveguide resonance mode behaviors specific to this quasi-dielectric system were then investigated. For structures with no lateral displacement between the slit-array plates, mode disappearance phenomena, which are caused by destructive interference between the odd-order mode and the blue- or red-shifted even-order modes, were observed experimentally. The uncommon behavior of the even-order modes was examined precisely to explain the slit-width dependence. For structures with half-pitched displacement between the plates, extraordinarily strong transmission was observed experimentally, even when the optical paths were shut off. This result was interpreted in terms of the propagation of surface plasmon polaritons through very thin and labyrinthine spacings that inevitably exist between the metallic plates. Furthermore, the optical mode disappearance phenomena are revealed to be characterized by anticrossing of the two mixing modes formed by even- and odd-order modes. These experimental observations that are supported theoretically are indispensable to the practical use of this type of artificial dielectric and are expected to encourage interest in optical mode behaviors that are not typically observed in conventional dielectric systems.

Fiber Temperature Sensor Based on Micro-mechanical Membranes and Optical Interference Structure

International Nuclear Information System (INIS)

Liu Yueming; Tian Weijian; Hua Jing

2011-01-01

A novel fiber temperature sensor is presented theoretically and experimentally in this paper. Its working principle is based on Optical Fabry-Perot interference structure that is formed between a polished optical fiber end and micro-mechanical Bi-layered membranes. When ambient temperature is varying, Bi-layered membranes will be deflected and the length of Fabry-Perot cavity will be changed correspondingly. By detecting the reflecting optical intensity from the Fabry-Perot cavity, the ambient temperature can be measured. Using finite element software ANSYS, the sensor structure was optimized based on optical Interference theory and Bi-layered membranes thermal expansion theory, and theoretical characteristics was simulated by computer software. In the end, using optical fiber 2x2 coupler and photo-electrical detector, the fabricated sample sensor was tested successfully by experiment that demonstrating above theoretical analysis and simulation results. This sensor has some favorable features, such as: micro size owing to its micro-mechanical structure, high sensitivity owing to its working Fabry-Perot interference cavity structure, and optical integration character by using optical fiber techniques.

As if Kyoto mattered: The clean development mechanism and transportation

International Nuclear Information System (INIS)

Christopher Zegras, P.

2007-01-01

Transportation is a major source of greenhouse gas (GHG) emissions and the most rapidly growing anthropogenic source. In the future, the developing world will account for the largest share of transport GHG increases. Four basic components drive transportation energy consumption and GHG emissions: activities (A), mode share (S), fuel intensity (I) and fuel choice (F) (ASIF). Currently, the Kyoto Protocol's clean development mechanism (CDM) serves as the main international market-based tool designed to reduce GHG emissions from the developing world. Theoretically, the CDM has the dual purpose of helping developing countries achieve 'sustainable development' goals and industrialized countries meet their Kyoto emissions reduction commitments. This paper reviews overall CDM activities and transportation CDM activities to date and then presents findings from three case studies of transportation CDM possibilities examined with the ASIF framework in Santiago de Chile. The analysis suggests that bus technology switch (I) provides a fairly good project fit for the CDM, while options aimed at inducing mode share (S) to bicycle, or modifying travel demand via land use changes (ASI) face considerable challenges. The implications of the findings for the CDM and the 'post-Kyoto' world are discussed

Urinary biomarker investigation in children with Fabry disease using tandem mass spectrometry.

Science.gov (United States)

Auray-Blais, Christiane; Blais, Catherine-Marie; Ramaswami, Uma; Boutin, Michel; Germain, Dominique P; Dyack, Sarah; Bodamer, Olaf; Pintos-Morell, Guillem; Clarke, Joe T R; Bichet, Daniel G; Warnock, David G; Echevarria, Lucia; West, Michael L; Lavoie, Pamela

2015-01-01

Fabry disease is an X-linked lysosomal storage disorder affecting both males and females with tremendous genotypic/phenotypic variability. Concentrations of globotriaosylceramide (Gb3), globotriaosylsphingosine (lyso-Gb3)/related analogues were investigated in pediatric and adult Fabry cohorts. The aims of this study were to transfer and validate an HPLC-MS/MS methodology on a UPLC-MS/MS new generation platform, using an HPLC column, for urine analysis of treated and untreated pediatric and adult Fabry patients, to establish correlations between the excretion of Fabry biomarkers with gender, treatment, types of mutations, and to evaluate the biomarker reliability for early detection of pediatric Fabry patients. A UPLC-MS/MS was used for biomarker analysis. Reference values are presented for all biomarkers. Results show that gender strongly influences the excretion of each biomarker in the pediatric Fabry cohort, with females having lower urinary levels of all biomarkers. Urinary distribution of lyso-Gb3/related analogues in treated Fabry males was similar to the untreated and treated Fabry female groups in both children and adult cohorts. Children with the late-onset p.N215S mutation had normal urinary levels of Gb3, and lyso-Gb3 but abnormal levels of related analogues. In this study, Fabry males and most Fabry females would have been diagnosed using the urinary lyso-Gb3/related analogue profile. Copyright © 2014 Elsevier B.V. All rights reserved.

GAME ANALYSIS OF KYOTO AND POST-KYOTO SCHEMES

Energy Technology Data Exchange (ETDEWEB)

Haruo Imai [Kyoto Institute of Economic Research, Kyoto University, Sakyo, Kyoto (Japan)

2008-09-30

Kyoto protocol, put in force in Feb. 2005, is criticized from both sides, those demanding a stricter target for GHG (green house gas) emission reduction on the one side, and those claiming for more flexible and comprehensive controls of the emission on the other side, for its modest target and narrow coverage. Even though its value could be that of a mere precedent and experimentation, Kyoto protocol includes very special experimentation to assist the world wide cooperation for a mitigation of climate change, i.e. the introduction of three mechanisms, emissions trading, joint implementation, and clean development mechanism (CDM). Together, they are called Kyoto mechanisms. Evaluation of mechanisms is one important role of microeconomics and the game theory is a major tool for it. We shall scrutinize these mechanisms from such viewpoint. A special attention is placed on CDM, as it is the novel mechanism introduced by Kyoto protocol, and gives a unique link between Annex I nations (mostly developed countries) and non-Annex I nations (mostly developing countries). Next, we examine some of the currently proposed schemes after 2013, the post Kyoto schemes. One of the chief issues is the possibility of making a comprehensive agreement including both the USA and large developing countries with rapidly increasing emission levels of GHG like China and India. Adding to these, not only the proposed schemes themselves, but the process of negotiation itself inspired several researches in cooperative game theory and in particular, coalition formation theory. We shall touch upon this issue separately, and examine how successfully they predicted the outcome leading to Kyoto, retrospectively. Finally, we end our discussion with a brief consideration over the underlining normative argument concerning these schemes.

Carbon credits after Kyoto

International Nuclear Information System (INIS)

Anon.

1998-01-01

In the Kyoto Protocol to the FCCC three different forms of GHG emission reduction titles through market-based international cooperation are defined: emission reduction units under Article 6; certified emission reductions in the framework of the Clean Development Mechanism (CDM) under Article 12; and emissions trading under Article 17. Although defined under different Articles in the Protocol, it seems reasonable to assume that the three mechanisms will not operate separately. After CoP3 the author registered several comments, opinions and concerns related to the flexibility provisions under the Kyoto Protocol

Effect of Surface Plasmon Coupling to Optical Cavity Modes on the Field Enhancement and Spectral Response of Dimer-Based sensors

KAUST Repository

Alrasheed, Salma

2017-09-05

We present a theoretical approach to narrow the plasmon linewidth and enhance the near-field intensity at a plasmonic dimer gap (hot spot) through coupling the electric localized surface plasmon (LSP) resonance of a silver hemispherical dimer with the resonant modes of a Fabry-Perot (FP) cavity. The strong coupling is demonstrated by the large anticrossing in the reflection spectra and a Rabi splitting of 76 meV. Up to 2-fold enhancement increase can be achieved compared to that without using the cavity. Such high field enhancement has potential applications in optics, including sensors and high resolution imaging devices. In addition, the resonance splitting allows for greater flexibility in using the same array at different wavelengths. We then further propose a practical design to realize such a device and include dimers of different shapes and materials.

Application of a fiber Fabry-Perot interferometer sensor for receiving SH-EMAT signals

Energy Technology Data Exchange (ETDEWEB)

Lee, Jin Hyuk; Kim, Dae Hyun; Park, Ik Keun [Seoul National University of Technology, Seoul (Korea, Republic of)

2014-04-15

Shear horizontal (SH) waves propagate as a type of plate wave in a thin sheet. The dispersion characteristics of SH waves can be used for signal analysis. Therefore, SH-waves are useful for monitoring the structural health of a thin-sheet-structure. An electromagnetic acoustic transducer (EMAT), which is a non-contact ultrasonic transducer, can generate SH-waves easily by varying the shape and array of magnets and coils. Therefore, an EMAT can be applied to an automated ultrasonic testing system for structural health monitoring. When used as a sensor, however, the EMAT has a weakness in that electromagnetic interference (EMI) noise can occur easily in the automated system because of motors and electric devices. Alternatively, a fiber optic sensor works well in the same environment with EMI noise because it uses a light signal instead of an electric signal. In this paper, a fiber Fabry-Prot interferometer (FFPI) was proposed as a sensor to receive the SH-waves generated by an EMAT. A simple test was performed to verify the performance of the FFPI sensor. It is thus shown that the FFPI can receive SH-wave signals clearly.

Integrated Photonics Research Topical Meeting (1993)

Science.gov (United States)

1994-06-01

phase epitaxy on (11 1)-oriented gadolinium -gallium-garnet substrates and were subjected to annealing procedures to ensure near-planar magnetization ...was measured using the Fabry -Perot resonance technique. The propagation losses in the waveguides with and without electrodes were approximately 2.8 and...expected sub-Angstrom range. The high frequency variations present throughout the entire signal are due to Fabry -Perot resonances from the end facets

Equatorial thermospheric winds: New results using data from a network of three Fabry-Perot interferometers located in central Peru

Science.gov (United States)

Meriwether, J. W.; Dominquez, L. N.; Milla, M. A.; Chau, J. L.; Makela, J. J.; Fisher, D.

2013-12-01

A new observing strategy aimed at improving our understanding of the properties of the equatorial thermosphere wind field, such as the vorticity and divergence, has been developed to generate maps of the thermospheric wind field. Estimates of the neutral wind are obtained from measurements of the Doppler shift of the thermospheric 630.0-nm emission obtained from a sequence of eight evenly spaced azimuthal directions for each of the three Fabry-Perot interferometer (FPI) observatories located in central Peru (Jicamarca, Nazca, and Arequipa). Measurements towards the zenith and a frequency-stabilized laser reference are also included in each sequence, which takes ~25 minutes to complete. Six of the off-zenith observing directions from the Nazca FPI observatory are used to make common volume (CV) measurements, where two of the FPIs observe the same thermospheric volume with a centroid height of ~250 km at orthogonal angles. These CV positions are located ~225 km north and south of the Nazca FPI observatory. The data obtained during a coordinated observation of the two FPIs observing the same CV location are used to compute estimates of the zonal (u) and meridional (v) wind components. The set of Doppler shifts measured by the three FPIs during a single sequence is used to produce a map of the neutral wind field for that period of time. The construction of this map is based upon the use of a first-order polynomial expansion of the neutral wind field relative to the site coordinates of each FPI location. This expansion includes the first-order gradients of u and v with respect to the zonal (x) and meridional (y) directions. Computation of the best fit in a linear least squares sense of the model expansion parameters to the Doppler shift data for all three sites determines the values of these gradient parameters. Results obtained for mid-winter 2013 show the anti-cyclonic circulation expected near the terminator generated by the day-to-night pressure gradient. Sequences

Electron cyclotron emission measurement in Tore Supra

International Nuclear Information System (INIS)

Javon, C.

1991-06-01

Electron cyclotron radiation from Tore-Supra is measured with Michelson and Fabry-Perot interferometers. Calibration methods, essential for this diagnostic, are developed allowing the determination of electron temperature in the plasma. In particular the feasibility of Fabry-Perot interferometer calibration by an original method is demonstrated. A simulation code is developed for modelling non-thermal electron population in these discharges using measurements in non-inductive current generation regime [fr

Cardiopulmonary involvement in Fabry's disease.

Science.gov (United States)

Koskenvuo, Juha W; Kantola, Ilkka M; Nuutila, Pirjo; Knuuti, Juhani; Parkkola, Riitta; Mononen, Ilkka; Hurme, Saija; Kalliokoski, Riikka; Viikari, Jorma S; Wendelin-Saarenhovi, Maria; Kiviniemi, Tuomas O; Hartiala, Jaakko J

2010-04-01

Fabry's disease is an X-linked lysosomal storage disease caused by deficiency of alpha-galactosidase A enzyme activity. Decreased enzyme activity leads to accumulation of glycosphingolipid in different tissues, including endothelial and smooth-muscle cells and cardiomyocytes. There is controversial data on cardiopulmonary involvement in Fabry's disease, because many reports are based on small and selected populations with Fabry's disease. Furthermore, the aetiology of cardiopulmonary symptoms in Fabry's disease is poorly understood. We studied cardiopulmonary involvement in seventeen patients with Fabry's disease (20-65 years, 6 men) using ECG, bicycle stress, cardiac magnetic resonance imaging, spirometry, diffusing capacity and pulmonary high-resolution computed tomography (HRCT) tests. Cardiopulmonary symptoms were compared to observed parameters in cardiopulmonary tests. Left ventricular hypertrophy (LVH) and reduced exercise capacity are the most apparent cardiac changes in both genders with Fabry's disease. ECG parameters were normal when excluding changes related to LVH. Spirometry showed mild reduction in vital capacity and forced expiratory volume in one second (FEV I), and mean values in diffusing capacity tests were within normal limits. Generally, only slight morphological pulmonary changes were detected using pulmonary HRCT, and they were not associated with changes in pulmonary function. The self-reported amount of pulmonary symptoms associated only with lower ejection fraction (P routine cardiopulmonary evaluation in Fabry's disease using echocardiography is maybe enough when integrated to counselling for aerobic exercise training.

Fabry disease: recent advances in pathology, diagnosis, treatment and monitoring

Directory of Open Access Journals (Sweden)

Hoffmann Björn

2009-10-01

Full Text Available Abstract Background In Fabry disease (α-galactosidase A deficiency accumulation of Globotriaosylceramide (Gb3 leads to progressive organ failure and premature death. The introduction of enzyme replacement therapy (ERT was the beginning of a new era in this disorder, and has prompted a broad range of research activities. This review aims to summarize recent developments and progress with high impact for Fabry disease. Methods A Pubmed analysis was performed using the search terms "Fabry disease", "Anderson-Fabry disease", "alpha-galactosidase A" and "Gb3". Of the given publications by 31st January 2009 only original articles recently published in peer reviewed journals were included for this review. Case reports were included only when they comprised a new aspect. In addition we included relevant conference abstracts when the results had not already been published as original articles. Results Apart from Gb3-accumulation cellular and organ specific damages may be related also to inflammatory and immunological consequences. It will be interesting whether this may lead to new therapeutic strategies in the treatment of Fabry disease. Since newborn screening is still difficult in Fabry disease, detection of patients in populations at risk is of great importance. Undiagnosed patients with Fabry disease may still be found in cohorts of subjects with renal diseases, cardiomyopathy and TIA or stroke. Efforts should be undertaken to identify these individuals and initialise ERT in order to hault disease progression. It has also been demonstrated that Gb3-accumulation leads to pre-clinical damages and it is believed that early treatment may be the only possibility so far to prevent irreversible organ damage.

Dysregulated autophagy contributes to podocyte damage in Fabry's disease.

Directory of Open Access Journals (Sweden)

Max C Liebau

Full Text Available Fabry's disease results from an inborn error of glycosphingolipid metabolism that is due to deficiency of the lysosomal hydrolase α-galactosidase A. This X-linked defect results in the accumulation of enzyme substrates with terminally α-glycosidically bound galactose, mainly the neutral glycosphingolipid Globotriaosylceramide (Gb3 in various tissues, including the kidneys. Although end-stage renal disease is one of the most common causes of death in hemizygous males with Fabry's disease, the pathophysiology leading to proteinuria, hematuria, hypertension, and kidney failure is not well understood. Histological studies suggest that the accumulation of Gb3 in podocytes plays an important role in the pathogenesis of glomerular damage. However, due to the lack of appropriate animal or cellular models, podocyte damage in Fabry's disease could not be directly studied yet. As murine models are insufficient, a human model is needed. Here, we developed a human podocyte model of Fabry's disease by combining RNA interference technology with lentiviral transduction of human podocytes. Knockdown of α-galactosidase A expression resulted in diminished enzymatic activity and slowly progressive accumulation of intracellular Gb3. Interestingly, these changes were accompanied by an increase in autophagosomes as indicated by an increased abundance of LC3-II and a loss of mTOR kinase activity, a negative regulator of the autophagic machinery. These data suggest that dysregulated autophagy in α-galactosidase A-deficient podocytes may be the result of deficient mTOR kinase activity. This finding links the lysosomal enzymatic defect in Fabry's disease to deregulated autophagy pathways and provides a promising new direction for further studies on the pathomechanism of glomerular injury in Fabry patients.

Biologically inspired flexible quasi-single-mode random laser: An integration of Pieris canidia butterfly wing and semiconductors

Science.gov (United States)

Wang, Cih-Su; Chang, Tsung-Yuan; Lin, Tai-Yuan; Chen, Yang-Fang

2014-10-01

Quasi-periodic structures of natural biomaterial membranes have great potentials to serve as resonance cavities to generate ecological friendly optoelectronic devices with low cost. To achieve the first attempt for the illustration of the underlying principle, the Pieris canidia butterfly wing was embedded with ZnO nanoparticles. Quite interestingly, it is found that the bio-inspired quasi-single-mode random laser can be achieved by the assistance of the skeleton of the membrane, in which ZnO nanoparticles act as emitting gain media. Such unique characteristics can be interpreted well by the Fabry-Perot resonance existing in the window-like quasi-periodic structure of butterfly wing. Due to the inherently promising flexibility of butterfly wing membrane, the laser action can still be maintained during the bending process. Our demonstrated approach not only indicates that the natural biological structures can provide effective scattering feedbacks but also pave a new avenue towards designing bio-controlled photonic devices.

Biologically inspired flexible quasi-single-mode random laser: an integration of Pieris canidia butterfly wing and semiconductors.

Science.gov (United States)

Wang, Cih-Su; Chang, Tsung-Yuan; Lin, Tai-Yuan; Chen, Yang-Fang

2014-10-23

Quasi-periodic structures of natural biomaterial membranes have great potentials to serve as resonance cavities to generate ecological friendly optoelectronic devices with low cost. To achieve the first attempt for the illustration of the underlying principle, the Pieris canidia butterfly wing was embedded with ZnO nanoparticles. Quite interestingly, it is found that the bio-inspired quasi-single-mode random laser can be achieved by the assistance of the skeleton of the membrane, in which ZnO nanoparticles act as emitting gain media. Such unique characteristics can be interpreted well by the Fabry-Perot resonance existing in the window-like quasi-periodic structure of butterfly wing. Due to the inherently promising flexibility of butterfly wing membrane, the laser action can still be maintained during the bending process. Our demonstrated approach not only indicates that the natural biological structures can provide effective scattering feedbacks but also pave a new avenue towards designing bio-controlled photonic devices.

Myocardial lipid content in Fabry disease: a combined 1H-MR spectroscopy and MR imaging study at 3 Tesla.

Science.gov (United States)

Petritsch, B; Köstler, H; Weng, A M; Horn, M; Gassenmaier, T; Kunz, A S; Weidemann, F; Wanner, C; Bley, T A; Beer, M

2016-10-28

Fabry disease is characterized by a progressive deposition of sphingolipids in different organ systems, whereby cardiac involvement leads to death. We hypothesize that lysosomal storage of sphingolipids in the heart as occurring in Fabry disease does not reflect in higher cardiac lipid concentrations detectable by 1 H magnetic resonance spectroscopy (MRS) at 3 Tesla. Myocardial lipid content was quantified in vivo by 1 H-MRS in 30 patients (12 male, 18 female; 18 patients treated with enzyme replacement therapy) with genetically proven Fabry disease and in 30 healthy controls. The study protocol combined 1 H-MRS with cardiac cine imaging and LGE MRI in a single examination. Myocardial lipid content was not significantly elevated in Fabry disease (p = 0.225). Left ventricular (LV) mass was significantly higher in patients suffering from Fabry disease compared to controls (p = 0.019). Comparison of patients without signs of myocardial fibrosis in MRI (LGE negative; n = 12) to patients with signs of fibrosis (LGE positive; n = 18) revealed similar myocardial lipid content in both groups (p > 0.05), while the latter showed a trend towards elevated LV mass (p = 0.076). This study demonstrates the potential of lipid metabolic investigation embedded in a comprehensive examination of cardiac morphology and function in Fabry disease. There was no evidence that lysosomal storage of sphingolipids influences cardiac lipid content as measured by 1 H-MRS. Finally, the authors share the opinion that a comprehensive cardiac examination including three subsections (LGE; 1 H-MRS; T 1 mapping), could hold the highest potential for the final assessment of early and late myocardial changes in Fabry disease.

Mode coupling in hybrid square-rectangular lasers for single mode operation

Energy Technology Data Exchange (ETDEWEB)

Ma, Xiu-Wen; Huang, Yong-Zhen, E-mail: yzhuang@semi.ac.cn; Yang, Yue-De; Xiao, Jin-Long; Weng, Hai-Zhong; Xiao, Zhi-Xiong [State Key Laboratory on Integrated Optoelectronics, Institute of Semiconductors and University of Chinese Academy of Sciences, Chinese Academy of Sciences, Beijing 100083 (China)

2016-08-15

Mode coupling between a square microcavity and a Fabry-Pérot (FP) cavity is proposed and demonstrated for realizing single mode lasers. The modulations of the mode Q factor as simulation results are observed and single mode operation is obtained with a side mode suppression ratio of 46 dB and a single mode fiber coupling loss of 3.2 dB for an AlGaInAs/InP hybrid laser as a 300-μm-length and 1.5-μm-wide FP cavity connected to a vertex of a 10-μm-side square microcavity. Furthermore, tunable single mode operation is demonstrated with a continuous wavelength tuning range over 10 nm. The simple hybrid structure may shed light on practical applications of whispering-gallery mode microcavities in large-scale photonic integrated circuits and optical communication and interconnection.

Kinematics of SNRs CTB 109 and G206.9+2.3

Science.gov (United States)

Rosado, Margarita; Sánchez-Cruces, Mónica; Ambrocio-Cruz, Patricia

2017-11-01

We present results of optical observations in the lines of Hα and [SII] (λ 6717 and 6731 Å) obtained with the UNAM Scanning Fabry-Perot Interferometer PUMA (Rosado et al. 1995,RMxAASC, 3, 263 ) aimed at obtaining the kinematical distance, shock velocity and other important parameters of two supernova remnants (SNRs) with optical counterparts. We discuss on how kinematical distances thus obtained fit with other distance determinations. The studied SNRs are CTB 109 (SNR G109.1 - 1.0) hosting a magnetar (Sánchez-Cruces et al. 2017, in preparation) and the SNR G206.9 + 2.3 (Ambrocio-Cruz et al. 2014,RMxAA, 50, 323), a typical supernova remnant, to have a comparison. In Fig. 1 is depicted the [SII] line emission of two filaments of the optical counterpart of SNR CTB 109. We find complex radial velocity profiles obtained with the Fabry-Perot interferometer, revealing the presence of different velocity components. From these velocity profiles we obtain the kinematical distance, an expansion velocity of 188 km/s and an initial energy of 8.1 x 1050 ergs. These values are rather typical of other SNRs regardless that SNR CTB 109 hosts a magnetar. Thus, the mechanical energy delivered in the supernova explosion forming the magnetar does not seem to impact more than other SNe explosions the interstellar medium. This work has been funded by grants IN103116 and 253085 from DGAPA-UNAM and CONACYT, respectively.

Electronically controllable spoof localized surface plasmons

Science.gov (United States)

Zhou, Yong Jin; Zhang, Chao; Yang, Liu; Xun Xiao, Qian

2017-10-01

Electronically controllable multipolar spoof localized surface plasmons (LSPs) are experimentally demonstrated in the microwave frequencies. It has been shown that half integer order LSPs modes exist on the corrugated ring loaded with a slit, which actually arise from the Fabry-Perot-like resonances. By mounting active components across the slit in the corrugated rings, electronic switchability and tunability of spoof LSPs modes have been accomplished. Both simulated and measured results demonstrate efficient dynamic control of the spoof LSPs. These elements may form the basis of highly integrated programmable plasmonic circuits in microwave and terahertz regimes.

How to make progress post-Kyoto

Energy Technology Data Exchange (ETDEWEB)

NONE

2003-07-01

This document provides papers presented during the workshop on ''how to make progress post-Kyoto'', hold at the French Institute of International Relations (IFRI) in Paris on march 19, 2003. The following topics were presented: reflections on Kyoto, guidance for the future, how to make progress post-kyoto, the lessons from the past; the Bonn voyage; US climate policy after Kyoto, elements of success; preparing for widening and deepening the kyoto protocol; capping emissions and costs; absolute versus intensity-based emissions caps; intensity targets in perspective; negotiating commitments for further emission reductions; exploring new tools; defining meaningful participation of developing countries in climate change mitigation; economic and environmental effectiveness of a technology-based climate regime; US participation in the linkage between research and development and climate cooperation; designing a technology strategy; ''greening'' economic development; some critical comments post-Kyoto; the foreign policy perspective of climate negotiations; Kyoto and the double spiral; burden-sharing rules for stabilizing greenhouse gas concentrations and their equity implications. (A.L.B.)

Topical Meeting on Photonic Switching Held in Incline Village, Nevada on 18-20 March 1987. Technical Digest Series. Volume 13.

Science.gov (United States)

1988-03-31

A 20 mil thick transparent non- magnetic single crystal garnet substrate such as gadolinium gallium garnet (Gd mGamO 1 ) is dipped into a mel+ and a 25...facets that causes Fabry -Perot resonances in the gain spectrum. The amplitude of this variation is determined by the product of the amplifier chip...fiers with large Fabry -Perot resonances will be of much use in photonic switching systems. .r Fortanately, coating technology is advancing rapidly and

All-optical clock recovery of NRZ-DPSK signals using optical resonator-type filters

DEFF Research Database (Denmark)

Peucheret, Christophe; Seoane, Jorge; Ji, Hua

2009-01-01

It is shown how introducing a limited rise time to the driving signal enables all-optical clock recovery of NRZ-DPSK signals generated using a phase modulator. A Fabry-Perot filter is used to generate the optical clock.......It is shown how introducing a limited rise time to the driving signal enables all-optical clock recovery of NRZ-DPSK signals generated using a phase modulator. A Fabry-Perot filter is used to generate the optical clock....

Acoustic transmission resonance and suppression through double-layer subwavelength hole arrays

International Nuclear Information System (INIS)

Liu Zhifeng; Jin Guojun

2010-01-01

We present a theoretical study of acoustic waves passing through double-layer subwavelength hole arrays. The acoustic transmission resonance and suppression are observed. There are three mechanisms responsible for the transmission resonance: the excitation of geometrically induced acoustic surface waves, the Fabry-Perot resonance in a hole cavity (I-FP resonance) and the Fabry-Perot resonance between two plates (II-FP resonance). We can differentiate these mechanisms via the dispersion relation of acoustic modes supported by the double-layer structure. It is confirmed that the coupling between two single-layer perforated plates, associated with longitudinal interval and lateral displacement, plays a crucial role in modulating the transmission properties. The strong coupling between two plates can induce the splitting of the transmission peak, while the decoupling between plates leads to the appearance of transmission suppression. By analyzing the criterion derived for transmission suppression, we conclude that it is the destructive interference between the diffracted waves and the direct transmission waves assisted by the I-FP resonance of the first plate that leads to the decoupling between plates and then the transmission suppression.

Genetics Home Reference: Fabry disease

Science.gov (United States)

... Stroke: Fabry's Disease Information Page National Institute of Neurological Disorders and Stroke: Lipid Storage Diseases Fact Sheet Educational Resources (8 links) Children Living With Inherited Metabolic Diseases (CLIMB) (UK): Fabry ...

Analysis of dual-mode lasing characteristics in a 1310-nm optically injected quantum dot distributed feedback laser

Science.gov (United States)

Raghunathan, R.; Olinger, J.; Hurtado, A.; Grillot, F.; Kovanis, V.; Lester, L. F.

2015-03-01

Recent work has shown the Quantum Dot (QD) material system to be well-suited to support dual-mode lasing. In particular, optical injection from a master laser (ML) into the residual Fabry-Perot (FP) modes of a 1310 nm Quantum Dot Distributed Feedback (QD-DFB) laser has been recently demonstrated to offer a highly reliable platform for stable dual-mode lasing operation. External controls on the ML, such as operating temperature and bias current, can be used to precisely adjust the spacing between the two lasing modes. This tunability of modeseparation is very promising for a range of applications requiring the generation of microwave, millimeter wave and terahertz signals. Considering the versatility and utility of such a scheme, it is imperative to acquire a deeper understanding of the factors that influence the dual-mode lasing process, in order to optimize performance. Toward this end, this paper seeks to further our understanding of the optically-injected dual-mode lasing mechanism. For fixed values of optical power injected into each FP residual mode and wavelength detuning, the dual-mode lasing characteristics are analyzed with regard to important system parameters such as the position and the intensity of the injected residual mode (relative to the Bragg and the other residual FP modes of the device) for two similarly-fabricated QD-DFBs. Results indicate that for dual mode lasing spaced less than 5 nm apart, the relative intensity of the injected FP mode and intracavity noise levels are critical factors in determining dual mode lasing behavior. Insight into the dual-mode lasing characteristics could provide an important design guideline for the master and QD-DFB slave laser cavities.

High-Sensitivity Troponin: A Clinical Blood Biomarker for Staging Cardiomyopathy in Fabry Disease.

Science.gov (United States)

Seydelmann, Nora; Liu, Dan; Krämer, Johannes; Drechsler, Christiane; Hu, Kai; Nordbeck, Peter; Schneider, Andreas; Störk, Stefan; Bijnens, Bart; Ertl, Georg; Wanner, Christoph; Weidemann, Frank

2016-05-31

High-sensitivity troponin (hs-TNT), a biomarker of myocardial damage, might be useful for assessing fibrosis in Fabry cardiomyopathy. We performed a prospective analysis of hs-TNT as a biomarker for myocardial changes in Fabry patients and a retrospective longitudinal follow-up study to assess longitudinal hs-TNT changes relative to fibrosis and cardiomyopathy progression. For the prospective analysis, hs-TNT from 75 consecutive patients with genetically confirmed Fabry disease was analyzed relative to typical Fabry-associated echocardiographic findings and total myocardial fibrosis as measured by late gadolinium enhancement (LE) on magnetic resonance imaging. Longitudinal data (3.9±2.0 years), including hs-TNT, LE, and echocardiographic findings from 58 Fabry patients, were retrospectively collected. Hs-TNT level positively correlated with LE (linear correlation coefficient, 0.72; odds ratio, 32.81 [95% CI, 3.56-302.59]; P=0.002); patients with elevated baseline hs-TNT (>14 ng/L) showed significantly increased LE (median: baseline, 1.9 [1.1-3.3] %; follow-up, 3.2 [2.3-4.9] %; PFabry disease and a qualified predictor of cardiomyopathy progression. Thus, hs-TNT could be helpful for staging and follow-up of Fabry patients. © 2016 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley Blackwell.

How to make progress post-Kyoto

Energy Technology Data Exchange (ETDEWEB)

NONE

2003-07-01

This document provides papers presented during the workshop on ''how to make progress post-Kyoto'', hold at the French Institute of International Relations (IFRI) in Paris on march 19, 2003. The following topics were presented: reflections on Kyoto, guidance for the future, how to make progress post-kyoto, the lessons from the past; the Bonn voyage; US climate policy after Kyoto, elements of success; preparing for widening and deepening the kyoto protocol; capping emissions and costs; absolute versus intensity-based emissions caps; intensity targets in perspective; negotiating commitments for further emission reductions; exploring new tools; defining meaningful participation of developing countries in climate change mitigation; economic and environmental effectiveness of a technology-based climate regime; US participation in the linkage between research and development and climate cooperation; designing a technology strategy; ''greening'' economic development; some critical comments post-Kyoto; the foreign policy perspective of climate negotiations; Kyoto and the double spiral; burden-sharing rules for stabilizing greenhouse gas concentrations and their equity implications. (A.L.B.)

Parkinson's disease prevalence in Fabry disease: A survey study

Directory of Open Access Journals (Sweden)

Adina H. Wise

2018-03-01

Full Text Available Recent research has suggested a possible link between Parkinson's disease (PD and Fabry disease. To test this relationship, we administered a self-report and family history questionnaire to determine the prevalence of PD in Fabry disease patients and family members with likely pathogenic alpha-galactosidase A (GLA mutations. A total of 90 Fabry patients (77 from the online survey and 13 from the Icahn School of Medicine at Mount Sinai (ISMMS were included in the analysis. Two of the Fabry disease patients who completed the online survey were diagnosed with PD (2/90, 2.2%. Among probands older than 60, 8.3% (2/24 were diagnosed with PD. Using Kaplan Meier survival analysis, the age-specific risk of PD by age 70 was 11.1%. Family history was available on 72 Fabry families from the online study and 9 Fabry families from ISMMS. Among these 81 families, 6 (7.4% had one first degree relative who fit the criteria for a conservative diagnosis of PD. The results of this study suggest that there may be an increased risk of developing PD in individuals with GLA mutations, but these findings should be interpreted with caution given the limitations of the study design.

Improvement of a triple-wavelength erbium-doped fiber laser using a Fabry–Perot laser diode

International Nuclear Information System (INIS)

Peng, P C; Hu, H L; Wang, J B

2013-01-01

This work demonstrates the feasibility of a simple construct of a tunable triple-wavelength fiber ring laser using a Fabry–Perot laser diode (FP-LD) and an optical tunable bandpass filter. An optical tunable bandpass filter is used within the cavity of an erbium-doped fiber laser to select the lasing wavelength. Because the Fabry–Perot laser diode is in combination with the tunable bandpass filter, the erbium-doped fiber laser can stably lase three wavelengths simultaneously. Moreover, this laser is easily tuned dynamically. This triple-wavelength output performs satisfactorily, with its optical side-mode-suppression-ratio (SMSR) exceeding 40 dB. Furthermore, the wavelength tuning range of this triple-wavelength erbium-doped fiber laser is greater than 27 nm. (paper)

Cognitive Impairments and Subjective Cognitive Complaints in Fabry Disease

DEFF Research Database (Denmark)

Loeb, Josefine; Feldt-Rasmussen, Ulla; Madsen, Christoffer Valdorff

2018-01-01

Fabry disease is a rare progressive X-linked lysosomal storage disorder which leads to neuropathic pain, organ dysfunction and cerebral pathology. Few studies have investigated cognitive impairment in Fabry disease and these previous studies are difficult to compare due to heterogeneous methodolo......Fabry disease is a rare progressive X-linked lysosomal storage disorder which leads to neuropathic pain, organ dysfunction and cerebral pathology. Few studies have investigated cognitive impairment in Fabry disease and these previous studies are difficult to compare due to heterogeneous...... methodological designs and small cohorts. The objective was to investigate the frequency of cognitive impairment in the Danish nationwide cohort of Fabry patients. Further, we examined if subjective cognitive complaints were associated with objective cognitive performances in this patient group....... Neuropsychological tests (17 measures) and evaluation of subjective complaints with the Perceived Deficits Questionnaire (PDQ) were applied in 41 of 63 patients. According to an a priori definition, 12 patients (29.3%) were cognitively impaired. Tests tapping psychomotor speed, attention and executive functions had...

Neurological manifestations in Fabry's disease

DEFF Research Database (Denmark)

Møller, Anette Torvin; Jensen, Troels Staehelin

2007-01-01

. Neurological symptoms, such as burning sensations (occasionally accompanied by acroparesthesia) and stroke, are among the first to appear, and occur in both male and female patients. A delay in establishing the diagnosis of Fabry's disease can cause unnecessary problems, especially now that enzyme replacement...... treatment is available to prevent irreversible organ damage. Females with Fabry's disease who present with pain have often been ignored and misdiagnosed because of the disorder's X-linked inheritance. This Review will stress the importance of recognizing neurological symptoms for the diagnosis of Fabry...

Modeling fiber Bragg grating device networks in photomechanical polymer optical fibers

Science.gov (United States)

Lanska, Joseph T.; Kuzyk, Mark G.; Sullivan, Dennis M.

2015-09-01

We report on the modeling of fiber Bragg grating (FBG) networks in poly(methyl methacrylate) (PMMA) polymer fibers doped with azo dyes. Our target is the development of Photomechanical Optical Devices (PODs), comprised of two FBGs in series, separated by a Fabry-Perot cavity of photomechanical material. PODs exhibit photomechanical multi-stability, with the capacity to access multiple length states for a fixed input intensity when a mechanical shock is applied. Using finite-difference time-domain (FDTD) numerical methods, we modeled the photomechanical response of both Fabry-Perot and Bragg-type PODs in a single polymer optical fiber. The polymer fiber was modeled as an instantaneous Kerr-type nonlinear χ(3) material. Our model correctly predicts the essential optical features of FBGs as well as the photomechanical multi-stability of nonlinear Fabry-Perot cavity-based PODs. Networks of PODs may provide a framework for smart shape-shifting materials and fast optical computation where the decision process is distributed over the entire network. In addition, a POD can act as memory, and its response can depend on input history. Our models inform and will accelerate targeted development of novel Bragg grating-based polymer fiber device networks for a variety of applications in optical computing and smart materials.

New GasB-based single-mode diode lasers in the NIR and MIR spectral regime for sensor applications

Science.gov (United States)

Milde, Tobias; Hoppe, Morten; Tatenguem, Herve; Honsberg, Martin; Mordmüller, Mario; O'Gorman, James; Schade, Wolfgang; Sacher, Joachim

2018-02-01

The NIR/MIR region between 1.8μm and 3.5μm contains important absorption lines for gas detection. State of the art are InP laser based setups, which show poor gain above 1.8μm and cannot be applied beyond 2.1μm. GaSb laser show a significantly higher output power (100mW for Fabry-Perot, 30mW for DFB). The laser design is presented with simulation and actual performance data. The superior performance of the GaSb lasers is verified in gas sensing applications. TDLAS and QEPAS measurements at trace gases like CH4, CO2 and N2O are shown to prove the spectroscopy performance.

Active Stabilization of a Diode Laser Injection Lock

OpenAIRE

Saxberg, Brendan; Plotkin-Swing, Benjamin; Gupta, Subhadeep

2016-01-01

We report on a device to electronically stabilize the optical injection lock of a semiconductor diode laser. Our technique uses as discriminator the peak height of the laser's transmission signal on a scanning Fabry-Perot cavity and feeds back to the diode current, thereby maintaining maximum optical power in the injected mode. A two-component feedback algorithm provides constant optimization of the injection lock, keeping it robust to slow thermal drifts and allowing fast recovery from sudde...

Circuit simulation model multi-quantum well laser diodes inducing transport and capture/escape

International Nuclear Information System (INIS)

Zhuber-Okrog, K.

1996-04-01

This work describes the development of world's first circuit simulation model for multi-quantum well (MQW) semiconductor lasers comprising caier transport and capture/escape effects. This model can be seen as the application of a new semiconductor device simulator for quasineutral structures including MQW layers with an extension for simple single mode modeling of optical behavior. It is implemented in a circuit simulation program. The model is applied to Fabry-Perot laser diodes and compared to measured data. (author)

Overview of recent results from the Tore Supra ECE diagnostics

International Nuclear Information System (INIS)

Talvard, M.; Liu, W.D.; Giruzzi, G.

1993-01-01

The Tore Supra ECE diagnostic system consists of a set of 3 Michelson and 12 Fabry-Perot interferometers, which is now fully operational. We present results obtained with the 3 Michelson during LHCD experiments first. It is shown how the sensitivity of the diagnostic to rather high v (perpendicular) prevents detection of v (parallel) anisotropies. On the other hand, measurements during the Ohmic phase reveal some unexpected anisotropy which can be attributed to superthermal electrons related to the bootstrap current. The 12 Fabry-Perot have been operated using high acquisition sampling rates during pellet injection experiments. A shudder preceding the pellet itself is clearly evidenced just before an internal disruption occurs. During sawtooth activity, such measurements are also used to study the dynamics of the m=1, n=1 instability on the q=1 surface itself

Urban landscape of Okazaki in Kyoto

Directory of Open Access Journals (Sweden)

Olimpia Niglio

2015-12-01

Full Text Available Kyoto has been the capital of Japan from 794 until when the capital has moved in 1868 to Tokyo with the end of Tokugawa Shoguns and the beginning of the Meiji Restoration. The loss of the seat of government was a shock to citizens of Kyoto as the city had been the Imperial and Cultural center of the nation for over 1.000 years. The combination of the court and the great temples had enlivened and enriched the life of the city. At the beginning of the founding of the capital, in the Heian period (794-1185 to east of Kyoto, was built a noble and religious place. This area is Okazaki. Here the Emperor Kammu (736-805 had created the city of Heian-kyo (Kyoto in 794. This area was full of Temples and Shrines. Only in the Edo period (1603-1867 Okazaki area assumed the role of suburban agricultural zone which provided the food production to the urban habitants. But after the Meiji Restoration (1868-1912, the role of Okazaki area changes completely. In 1885, Kyoto prefecture started the great public canalization project as the water supply between Kyoto and Otsu of Shiga prefecture. Kyoto prefecture also planed the industrial district construction in Okazaki area. From the late nineteenth century Okazaki area became a symbol of the modernization of Kyoto city. This contribution intends to analyze the urban landscape composed of the different styles of architecture especially constructed after the Meiji period (1868-1912. Tangible and intangible signs remained as modern gardens, significant museums and cultural institutions among the ancient temples provide opportunities to reflect on the important role of suburban area of the historic city. These studies are supported by archival documents and by current measures and policies for landscape conservation by Kyoto Municipality.

In vivo high-resolution 3D photoacoustic imaging of superficial vascular anatomy

International Nuclear Information System (INIS)

Zhang, E Z; Laufer, J G; Beard, P C; Pedley, R B

2009-01-01

The application of a photoacoustic imaging instrument based upon a Fabry-Perot polymer film ultrasound sensor to imaging the superficial vasculature is described. This approach provides a backward mode-sensing configuration that has the potential to overcome the limitations of current piezoelectric based detection systems used in superficial photoacoustic imaging. The system has been evaluated by obtaining non-invasive images of the vasculature in human and mouse skin as well as mouse models of human colorectal tumours. These studies showed that the system can provide high-resolution 3D images of vascular structures to depths of up to 5 mm. It is considered that this type of instrument may find a role in the clinical assessment of conditions characterized by changes in the vasculature such as skin tumours and superficial soft tissue damage due to burns, wounds or ulceration. It may also find application in the characterization of small animal cancer models where it is important to follow the tumour vasculature over time in order to study its development and/or response to therapy.

In vivo high-resolution 3D photoacoustic imaging of superficial vascular anatomy

Energy Technology Data Exchange (ETDEWEB)

Zhang, E Z; Laufer, J G; Beard, P C [Department of Medical Physics and Bioengineering, University College London, Gower Street, London, WC1E 6BT (United Kingdom); Pedley, R B [UCL Cancer Institute, Paul O' Gorman Building, University College London, 72 Huntley St, London WC1E 6BT (United Kingdom)

2009-02-21

The application of a photoacoustic imaging instrument based upon a Fabry-Perot polymer film ultrasound sensor to imaging the superficial vasculature is described. This approach provides a backward mode-sensing configuration that has the potential to overcome the limitations of current piezoelectric based detection systems used in superficial photoacoustic imaging. The system has been evaluated by obtaining non-invasive images of the vasculature in human and mouse skin as well as mouse models of human colorectal tumours. These studies showed that the system can provide high-resolution 3D images of vascular structures to depths of up to 5 mm. It is considered that this type of instrument may find a role in the clinical assessment of conditions characterized by changes in the vasculature such as skin tumours and superficial soft tissue damage due to burns, wounds or ulceration. It may also find application in the characterization of small animal cancer models where it is important to follow the tumour vasculature over time in order to study its development and/or response to therapy.

Rabi-like splitting from large area plasmonic microcavity

Directory of Open Access Journals (Sweden)

Fatemeh Hosseini Alast

2017-08-01

Full Text Available Rabi-like splitting was observed from a hybrid plasmonic microcavity. The splitting comes from the coupling of cavity mode with the surface plasmon polariton mode; anti-crossing was observed alongside the modal conversional channel on the reflection light measurement. The hybrid device consists of a 10x10 mm2 ruled metal grating integrated onto the Fabry-Perot microcavity. The 10x10 mm2 ruled metal grating fabricated from laser interference and the area is sufficiently large to be used in the practical optical device. The larger area hybrid plasmonic microcavity can be employed in polariton lasers and biosensors.

In-Building Wireless Distribution in legacy Multimode Fiber with an improved RoMMF system

DEFF Research Database (Denmark)

Visani, Davide; Petersen, Martin Nordal; Sorci, Francesca

2012-01-01

A radio over multimode fiber (RoMMF) system for in-building wireless distribution employing a directly modulated Fabry-Perot (FP) transmitter and the central launch technique is presented. The worst-case spurious free dynamic range (SFDR) exceeds 105 dB×Hz2/3 up to 525 m of OM2 multimode fiber (MMF......). Experimental and theoretical results are reported showing that this scheme outperforms a RoMMF system employing a distributed feed-back (DFB) laser diode (LD) and/or a mode scrambler to achieve overfilled launch (OFL). Long Term Evolution (LTE) signal transmission is achieved with high quality in terms...... of Adjacent Channel Leakage Ratio (ACLR) and Error Vector Magnitude (EVM)....

Design and Optimization of Dual Optical Fiber MEMS Pressure Sensor For Biomedical Applications

International Nuclear Information System (INIS)

Dagang, Guo; Po, Samuel Ng Choon; Hock, Francis Tay Eng; Rongming, Lin

2006-01-01

A novel Single Deeply Corrugated Diaphragm (SDCD) based dual optical fiber Fabry-Perot pressure sensor for blood pressure measurement is proposed. Both mechanical and optical simulations are performed to demonstrate the feasibility and superior performance of the proposed sensor. Result shows that less than 2% nonlinearity can be achieved for the proposed sensor using optimal Fabry-Perot microcavity. Also, the fabrication process of the proposed sensor is given, instead of complicated fusion bonding process, only bulk and surface micromachining techniques are required which facilitate the mass production of such biocompatible and disposable pressure sensors

Report: demonstrable progresses of the France according the Kyoto protocol; Rapport: progres demontrables de la France selon le protocole de Kyoto

Energy Technology Data Exchange (ETDEWEB)

NONE

2006-06-15

This document constitutes the report of the France on the demonstrable progresses according the application of the 3 article of the Kyoto protocol. The first chapter is a description of the french climatic policy, as the second presents the tendencies and the projections concerning the greenhouse effect gases emissions. The chapter 3 details the policies effects and the measures ( energy, transport, industry and wastes). The last chapter is devoted to the respect of the other engagements articles 10 and 11 of the Kyoto protocol. (A.L.B.)

Nailfold capillaroscopy: Specific features in Fabry disease.

Science.gov (United States)

Wasik, Jan S; Simon, Roger W; Meier, Thomas; Steinmann, Beat; Amann-Vesti, Beatrice R

2009-01-01

Fabry disease is a rare X-linked disorder caused by deficiency of alpha-galactosidase A. The metabolic defect results in the progressive accumulation of globotriaosylceramide within vascular cells leading to renal, cardiac and cerebrovascular manifestations. The aim of this study was to evaluate nailfold capillaroscopy as a non-invasive diagnostic tool in Fabry disease and to characterize morphological and functional changes of the capillaries in vivo. Twenty-five consecutive patients with Fabry disease (17 males) without enzyme-replacement therapy had been studied by fluorescence nailfold capillaroscopy. Macrocirculation of digital arteries was tested by digital pulse volume recording and patients had been asked about the presence of Raynaud phenomenon. Significant more bushy capillaries and clusters were present in Fabry patients (72%) compared to healthy controls (10%). No avascular fields had been seen, and in only one patient atypical architecture and in another one a giant capillary was present. Enhanced natrium-fluorescein diffusion into the pericapillary area has been observed in three male patients. Six patients (one female) reported Raynaud phenomenon of all fingers. In Fabry disease morphological and functional microangiopathy of nailfold capillaries is present. Furthermore, these new findings might explain, at least in part, the unusual high frequency of Raynaud phenomenon in Fabry patients, which has not been described so far. Our data suggest that capillaroscopy might be used as an additional non-invasive diagnostic tool for Fabry disease.

Demonstration of slot-waveguide structures on silicon nitride / silicon oxide platform.

Science.gov (United States)

Barrios, C A; Sánchez, B; Gylfason, K B; Griol, A; Sohlström, H; Holgado, M; Casquel, R

2007-05-28

We report on the first demonstration of guiding light in vertical slot-waveguides on silicon nitride/silicon oxide material system. Integrated ring resonators and Fabry-Perot cavities have been fabricated and characterized in order to determine optical features of the slot-waveguides. Group index behavior evidences guiding and confinement in the low-index slot region at O-band (1260-1370nm) telecommunication wavelengths. Propagation losses of <20 dB/cm have been measured for the transverse-electric mode of the slot-waveguides.

The Kyoto Mechanisms and Technological Innovation

DEFF Research Database (Denmark)

Lund, Henrik

2003-01-01

Climate change response, including implementation of the Kyoto targets as the first step, calls for technological innovation of future sustainable energy systems. One of the important agreements in several declarations, including the Kyoto protocol, has been to promote and coordinate...... the collaboration between the countries in the necessary technological development. The paper encourage that the Kyoto mechanisms will be used for acceleration of the necessary technical innovation in Denmark....

A study for reduction of radiation pressure noise in gravitational wave detectors

Energy Technology Data Exchange (ETDEWEB)

Sakata, S; Sugamoto, A [Graduate School of Humanities and Sciences, Ochanomizu University, 2-1-1 Otsuka, Bunkyo-ku, Tokyo, 112-8610 (Japan); Leonhardt, V; Kawamura, S; Sato, S; Yamazaki, T; Fukushima, M [National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan); Numata, K [NASA Goddard Space Flight Center, CRESST, Code 663, Greenbelt, MD 20771 (United States); Miyakawa, O [LIGO Laboratory 18-34, California Institute of Technology, Pasadena, CA 91125 (United States); Nishizawa, A [Graduate School of Human and Environmental Studies, Kyoto University, Kyoto 606-8501 (Japan); Furusawa, A [Department of Applied Physics, School of Engineering, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656 (Japan)], E-mail: shihori.sakata@nao.ac.jp

2008-07-15

We describe an experimental conceptual design for observation and reduction of radiation pressure noise. The radiation pressure noise is increased in a high finesse cavity with a small mass mirror. In our experiment a Fabry-Perot Michelson interferometer with a homodyne detection scheme will be built with Fabry-Perot cavities of finesse of 10000 containing suspended mirrors of 23 mg. To observe the radiation pressure noise, the goal sensitivity is set to 1x10{sup -17} [m/ {radical}Hz] at 1 kHz. Then the radiation pressure noise is reduced by adjusting the homodyne phase. To achieve the sensitivity, the other noise sources such as thermal noises, seismic noise and laser frequency noise should be suppressed below 1x10{sup -18} [m/{radical} Hz] at 1kHz. The whole interferometer is suspended as a double pendulum on double-layer stacks. As a preliminary setup, a Fabry-Perot cavity of finesse of 800 with a suspended mirror of 100 mg was locked. The current best sensitivity is 1x10{sup -15} [m/ {radical}Hz] at 1 kHz.

Beta Cell Workshop 2013 Kyoto

DEFF Research Database (Denmark)

Heller, R Scott; Madsen, Ole D; Nielsen, Jens Høiriis

2013-01-01

The very modern Kyoto International Conference Center provided the site for the 8th workshop on Beta cells on April 23-26, 2013. The preceding workshops were held in Boston, USA (1991); Kyoto, Japan (1994); Helsingør, Denmark (1997); Helsinki, Finland (2003); El Perello, Spain (2006); Peebles...

Klimadiplomatiets afveje i Kyoto-processen

DEFF Research Database (Denmark)

Czeskleba-Dupont, Rolf

2014-01-01

Operationaliseringen af de i 1992 i Rio indgåede forpligtelser i forhold til UNFCCC (FNs Rammekonventionom klimaforandringerne) blev siden COP3 i Kyoto under dominerende indflydelse af USAs forhandlere. Kritik af resultaterne kom allerede i 1998 fra den tyske regerings rådgivere i WGBU, men blev...

Clinical heterogeneity in Fabry disease

Directory of Open Access Journals (Sweden)

G. N. Salogub

2015-01-01

Full Text Available Fabry disease is an X-linked, lysosomal storage disease (OMIM: 301500, caused by α-galactosidase A deficiency, resulting in accumulation of its substrates, glycosphingolipids, primarily – globotriaosylceramide, in the lysosomes of multiple cell types with multi-system clinical manifestations, even within the same family, including abnormalities of the central and peripheral nervous system, kidneys, heart, gastrointestinal tract, lungs, organ of vision. Clinical heterogeneity is often the reason of the delayed diagnosis. Nowadays enzyme replacement therapy has proved its efficiency in the treatment of Fabry disease. Including Fabry disease in the differential diagnosis of a large range of disorders is important because of its wide clinical heterogeneity and the possibility of an earlier intervention with a beneficial treatment.

Kyoto protocol and related issues; Chikyu ondanka boshi Kyoto kaigi (COP3) to sono kadai

Energy Technology Data Exchange (ETDEWEB)

Ninomiya, Y. [Global Industrial Social Progress Research Institute, Tokyo (Japan)

1997-09-30

The Third Session of the Conference of the Parties to the United Nations Framework Convention on Climate Change (COP3) will be held in Kyoto in December 1997. Described herein are the current status and issues of the convention. USA and Japan, which hold important keys to set up the abatement target, have issued no proposals concretely at the current AGBM (Ad-hoc Group Berlin Mandate) 7, and the conference for the concrete targets will be decided in the next AGBM 8 to be held in October. The final target will be set by the ministerial segment of COP3, because the negotiations for the treaty are political in nature. USA proposes reduction at a uniform, realistic rate, and Japan proposes reduction at a uniform rate or setting up the emission target per capita, each being different from reduction at a much higher uniform rate proposed by EU. Within EU, however, 10% out of 15% reduction rate it proposes is agreed by the member countries, and the remaining rate of % may not be agreed. It is necessary for the advanced parties to set up realistic and legally binding solutions, including ratification by USA, which can persuade the developing countries. tab.1

Dual-wavelength passive and hybrid mode-locking of 3, 4.5 and 10 GHz InAs/InP(100) quantum dot lasers

NARCIS (Netherlands)

Tahvili, M.S.; Du, L.; Heck, M.J.R.; Nötzel, R.; Smit, M.K.; Bente, E.A.J.M.

2012-01-01

We present an investigation of passive and hybrid mode-locking in Fabry-Pérot type two-section InAs/InP(100) quantum dot lasers that show dual wavelength operation. Over the whole current and voltage range for mode-locking of these lasers, the optical output spectra show two distinct lobes. The two

HARLIE 3-D Aerosol Backscatter and Wind Profile Measurements During Recent Field Experiments: Background Noise Reduction with a Fabry-Perot Etalon Filter in the HARLIE System

Science.gov (United States)

Lee, Sangwoo; Miller, David O.; Schwemmer, Geary; Wilkerson, Thomas D.; Andrus, Ionio; Egbert, Cameron; Anderson, Mark; Starr, David OC. (Technical Monitor)

2002-01-01

Background noise reduction of War signals is one of the most important factors in achieving better signal to noise ratio and precise atmospheric data from Mar measurements. Fahey Perot etalons have been used in several lidar systems as narrow band pass filters in the reduction of scattered sunlight. An slalom with spectral bandwidth, (Delta)v=0.23/cm, free spectral range, FSR=6.7/cm, and diameter, d=24mm was installed in a fiber coupled box which included a 500 pm bandwidth interference Filter. The slalom box couples the telescope and detector with 200 pm core fibers and 21 mm focal length collimators. The angular magnification is M=48. The etalon box was inserted into the Holographic Airborne Rotating Lidar Instrument Experiment (HARLIE) system and tested during the HARGLO-2 intercomparison campaign conducted in November 2001 at Wallops Island, Virginia. This paper presents the preliminary test results of the slalom and a complete analysis will be presented at the conference.

Plasmonic photonic crystals realized through DNA-programmable assembly.

Science.gov (United States)

Park, Daniel J; Zhang, Chuan; Ku, Jessie C; Zhou, Yu; Schatz, George C; Mirkin, Chad A

2015-01-27

Three-dimensional dielectric photonic crystals have well-established enhanced light-matter interactions via high Q factors. Their plasmonic counterparts based on arrays of nanoparticles, however, have not been experimentally well explored owing to a lack of available synthetic routes for preparing them. However, such structures should facilitate these interactions based on the small mode volumes associated with plasmonic polarization. Herein we report strong light-plasmon interactions within 3D plasmonic photonic crystals that have lattice constants and nanoparticle diameters that can be independently controlled in the deep subwavelength size regime by using a DNA-programmable assembly technique. The strong coupling within such crystals is probed with backscattering spectra, and the mode splitting (0.10 and 0.24 eV) is defined based on dispersion diagrams. Numerical simulations predict that the crystal photonic modes (Fabry-Perot modes) can be enhanced by coating the crystals with a silver layer, achieving moderate Q factors (∼10(2)) over the visible and near-infrared spectrum.

A comprehensive Fabry-related pain questionnaire for adult patients.

Science.gov (United States)

Üçeyler, Nurcan; Magg, Barbara; Thomas, Phillip; Wiedmann, Silke; Heuschmann, Peter; Sommer, Claudia

2014-11-01

Pain may be the earliest symptom in Fabry disease and presents with a distinct phenotype including triggerable pain attacks, evoked pain, pain crises, and chronic pain. Current pain questionnaires do not reflect the special phenotype of Fabry disease-associated pain, which hampers its systematic evaluation as the basis of correct diagnosis and effective treatment. A questionnaire specifically designed to assess Fabry disease-associated pain is thus urgently needed. At the Würzburg Fabry Center for Interdisciplinary Therapy (FAZIT), Germany, we developed and validated the first face-to-face Fabry Pain Questionnaire (FPQ) for adult patients. The initial version of the FPQ was tested in a pilot study with 20 consecutive Fabry disease patients. The performance of the revised FPQ was assessed in a first (n=56) and second (n=20) validation phase in consecutive Fabry disease patients. For this, patients were interviewed at baseline and 2 weeks later. We determined the test-retest reliability and validity of the FPQ in comparison to data obtained with the Neuropathic Pain Symptom Inventory. The FPQ contains 15 questions on the 4 pain phenotypes of Fabry disease (pain attacks, pain crises, evoked pain, chronic pain) in childhood and adulthood, on pain development during life with and without enzyme replacement therapy, and on everyday life impairment due to pain. This first disease-specific questionnaire is a valuable tool for baseline and follow-up assessment of pain in Fabry disease patients and may guide treatment in this distinct pain phenotype. Copyright © 2014 International Association for the Study of Pain. Published by Elsevier B.V. All rights reserved.

An All-optical 3R Regenerator Using Fiber-based Four Wave Mixing

Directory of Open Access Journals (Sweden)

Theint Theint Htike

2015-07-01

Full Text Available Abstract All optical 3R regeneration is a key function of the future all optical network and ultra-long-haul transmission. In this paper all-optical regenerator utilizes a Fabry-Perot F-P filter for clock recovery four wavemixing based in a 500m-long highly nonlinear fiber and optical band pass filter for retiming and reshaping. A 10Gbs RZ signal was transmitted through 1200 km with a power penalty of 1dB at a BER of 10-9 compared to the back-to-back case. All optical 3R is shown to improve the performance of input signals degraded by transmission impairments and timing jitter of 10ps is reduced.

Five-beam Fabry-Perot velocimeter

Energy Technology Data Exchange (ETDEWEB)

Druce, R.L.; Goosman, D.G.; Collins, L.F.

1996-03-04

Velocimetry is useful in diagnosing many properties of high-explosive (HE) systems. The shock pressure of the detonation wave in HE is often measured by noting the velocity of an interface between the HE and a known material. Properties of the equation of state (EOS) of an explosive can be measured in a cylinder event using a combination of velocimetry and other diagnostics. Point-initiated explosions driving large plates give additional information regarding HE EOS. Hemispherical booster shots give quantitative data pertaining to booster performance. Velocimetry is used routinely to measure the performance of detonators. Velocimetry will be a particularly effective tool in cylinder shots, flat plate, and booster shots to determine the effects of aging on the EOS of explosive components in stockpile devices.

Plasmonic coaxial Fabry-Pérot nanocavity color filter

Science.gov (United States)

Si, G. Y.; Leong, E. S. P.; Danner, A. J.; Teng, J. H.

2010-08-01

Plamonic coaxial structures have drawn considerable attetion recently because of their unique properties. They exhibit different mechanisms of extraordinary optical transmission observed from subwavelength holes and they can support localized Fabry-Pérot plasmon modes. In this work, we experimentally demonstrate color filters based on coaxial structures fabricated in optically thick metallic films. Using nanogaps with different apertures from 160 nm down to only 40 nm, we show varying color outputs when the annular aperture arrays are illuminated with a broadband light source. Effective color-filter function is demonstrated in the optical regime. Different color outputs are observed and optical spectra are measured. In such structures, it is the propagating mode playing an important role rather than the evanescent. Resonances depend strongly on ring apertures, enabling devices with tunability of output colors using simple geometry control.

Highly versatile fiber-based optical Fabry-Pérot gas sensor.

Science.gov (United States)

Liu, Jing; Sun, Yuze; Fan, Xudong

2009-02-16

We develop a versatile, compact, and sensitive fiber-based optical Fabry-Pérot (FP) gas sensor. The sensor probe is composed of a silver layer and a vapor-sensitive polymer layer that are sequentially deposited on the cleaved fiber endface, thus forming an FP cavity. The interference spectrum resulting from the reflected light at the silver-polymer and polymer-air interfaces changes when the polymer is exposed to gas analytes. This structure enables using any polymer regardless of the polymer refractive index (RI), which significantly enhances the sensor versatility. In experiments, we use polyethylene glycol (PEG) 400 (RI=1.465-1.469) and Norland Optical Adhesive (NOA) 81 (RI=1.53-1.56) as the gas sensing polymer and show drastically different sensor response to hexanol, methanol, and acetone. The estimated sensitivity for methanol vapor is 3.5 pm/ppm and 0.1 pm/ppm for PEG 400 and NOA 81, respectively, with a detection limit on the order of 1-10 ppm. Gas sensing for the analytes delivered in both continuous flow mode and pulsed mode is demonstrated.

A Novel Rapid MALDI-TOF-MS-Based Method for Measuring Urinary Globotriaosylceramide in Fabry Patients

Science.gov (United States)

Alharbi, Fahad J.; Geberhiwot, Tarekegn; Hughes, Derralynn A.; Ward, Douglas G.

2016-04-01

Fabry disease is an X-linked lysosomal storage disorder caused by deficiency of α-galactosidase A, resulting in the accumulation of glycosphingolipids in various organs. Globotriaosylceramide (Gb3) and its isoforms and analogues have been identified and quantified as biomarkers of disease severity and treatment efficacy. The current study aimed to establish rapid methods for urinary Gb3 extraction and quantitation. Urine samples from 15 Fabry patients and 21 healthy control subjects were processed to extract Gb3 by mixing equal volumes of urine, methanol containing an internal standard, and chloroform followed by sonication and centrifugation. Thereafter, the lower phase was analyzed by MALDI-TOF MS and the relative peak areas of the internal standard and four major species of Gb3 determined. The results showed high reproducibility with intra- and inter-assay coefficients variation of 9.9% and 13.7%, respectively. The limit of detection was 0.15 ng/μL and the limit of quantitation was 0.30 ng/μL. Total urinary Gb3 levels in both genders of classic Fabry patients were significantly higher than in healthy controls (p < 0.0001). Gb3 levels in Fabry males were higher than in Fabry females (p = 0.08). We have established a novel assay for urinary total Gb3 that takes less than 15 min from start to finish.

Ultraviolet lasing behavior in ZnO optical microcavities

Directory of Open Access Journals (Sweden)

Hongxing Dong

2017-12-01

Full Text Available Zinc oxide (ZnO optical microcavity modulated UV lasers have been attracting a wide range of research interests. As one of the most important materials in developing high quality microcavity and efficient UV–visible optoelectronic devices due to its wide band gap (3.37 eV and large exciton binding energy (∼60 meV. In this review, we summarized the latest development of ZnO optical cavity based microlasers, mainly including Fabry-Perot mode lasers and whispering gallery mode lasers. The synthesis and optical studies of ZnO optical microcavities with different morphologies were discussed in detail. Finally, we also consider that the research focus in the near future would include new nanotechnology and physical effects, such as nano/micro fabrication, surface plasmon enhancement, and quantum dot coupling, which may result in new and interesting physical phenomena.

Multiple infrared bands absorber based on multilayer gratings

Science.gov (United States)

Liu, Xiaoyi; Gao, Jinsong; Yang, Haigui; Wang, Xiaoyi; Guo, Chengli

2018-03-01

The present study offers an Ag/Si multilayer-grating microstructure based on an Si substrate. The microstructure exhibits designable narrowband absorption in multiple infrared wavebands, especially in mid- and long-wave infrared atmospheric windows. We investigate its resonance mode mechanism, and calculate the resonance wavelengths by the Fabry-Perot and metal-insulator-metal theories for comparison with the simulation results. Furthermore, we summarize the controlling rules of the absorption peak wavelength of the microstructure to provide a new method for generating a Si-based device with multiple working bands in infrared.

Report: demonstrable progresses of the France according the Kyoto protocol

International Nuclear Information System (INIS)

2006-06-01

This document constitutes the report of the France on the demonstrable progresses according the application of the 3 article of the Kyoto protocol. The first chapter is a description of the french climatic policy, as the second presents the tendencies and the projections concerning the greenhouse effect gases emissions. The chapter 3 details the policies effects and the measures ( energy, transport, industry and wastes). The last chapter is devoted to the respect of the other engagements articles 10 and 11 of the Kyoto protocol. (A.L.B.)

Measurements of the Michigan Airglow Observatory from 1971 to 1973 at Ester Dome Alaska

Science.gov (United States)

Mcwatters, K. D.; Meriwether, J. W.; Hays, P. B.; Nagy, A. F.

1973-01-01

The Michigan Airglow Observatory (MAO) was located at Ester Dome Observatory, College, Alaska (latitude: 64 deg 53'N, longitude: 148 deg 03'W) since October, 1971. The MAO houses a 6-inch Fabry-Perot interferometer, a 2-channel monitoring photometer and a 4-channel tilting filter photometer. The Fabry-Perot interferometer was used extensively during the winter observing seasons of 1971-72 and 1972-73 to measure temperature and mass motions of the neutral atmosphere above approximately 90 kilometers altitude. Neutral wind data from the 1971-72 observing season as measured by observing the Doppler shift of the gamma 6300 A atomic oxygen emission line are presented.

Prognostic indicators of renal disease progression in adults with Fabry disease: natural history data from the Fabry Registry

NARCIS (Netherlands)

Wanner, Christoph; Oliveira, João P.; Ortiz, Alberto; Mauer, Michael; Germain, Dominique P.; Linthorst, Gabor E.; Serra, Andreas L.; Maródi, László; Mignani, Renzo; Cianciaruso, Bruno; Vujkovac, Bojan; Lemay, Roberta; Beitner-Johnson, Dana; Waldek, Stephen; Warnock, David G.

2010-01-01

These analyses were designed to characterize renal disease progression in untreated adults with Fabry disease. Data from the Fabry Registry for 462 untreated adults (121 men and 341 women) who had at least two estimated GFR (eGFR) values over a span of ≥12 months before starting enzyme replacement

Quantitative comparison of 2D and 3D late gadolinium enhancement MR imaging in patients with Fabry disease and hypertrophic cardiomyopathy.

Science.gov (United States)

Morsbach, F; Gordic, S; Gruner, C; Niemann, M; Goetti, R; Gotschy, A; Kozerke, S; Alkadhi, H; Manka, R

2016-08-15

This study aims to determine whether the quantification of myocardial fibrosis in patients with Fabry disease (FD) and hypertrophic cardiomyopathy (HCM) using a late gadolinium enhancement (LGE) singlebreath-hold three-dimensional (3D) inversion recovery magnetic resonance (MR) imaging sequence is comparable with a clinically established two-dimensional (2D) multi-breath-hold sequence. In this retrospective, IRB-approved study, 40 consecutive patients (18 male; mean age 50±17years) with Fabry disease (n=18) and HCM (n=22) underwent MR imaging at 1.5T. Spatial resolution was the same for 3D and 2D images (field-of-view, 350×350mm(2); in-plane-resolution, 1.2×1.2mm(2); section-thickness, 8mm). Datasets were analyzed for subjective image quality; myocardial and fibrotic mass, and total fibrotic tissue percentage were quantified. There was no significant difference in subjective image quality between 3D and 2D acquisitions (P=0.1 and P=0.3) for either disease. In patients with Fabry disease there were no significant differences between 3D and 2D acquisitions for myocardial mass (P=0.55), fibrous tissue mass (P=0.89), and total fibrous percentage (P=0.67), with good agreement between acquisitions according to Bland-Altman analyses. In patients with HCM there were also no significant differences between acquisitions for myocardial mass (P=0.48), fibrous tissue mass (P=0.56), and total fibrous percentage (P=0.67), with good agreement according to Bland-Altman analyses. Acquisition time was significantly shorter for 3D (25±5s) as compared to the 2D sequence (349±62s, P<0.001). In patients with Fabry disease and HCM, 3D LGE imaging provides equivalent diagnostic information in regard to quantification of myocardial fibrosis as compared with a standard 2D sequence, but at superior acquisition speed. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Fabry disease in children: a federal screening programme in Russia.

Science.gov (United States)

Namazova-Baranova, Leyla Seymurovna; Baranov, Alexander Alexandrovich; Pushkov, Aleksander Alekseevich; Savostyanov, Kirill Victorovich

2017-10-01

Our objective was to examine the prevalence of Fabry disease in Russian children with chronic pain in the distal limbs. This non-interventional, multi-centre study included children 2-18 years of age with chronic recurrent unilateral or bilateral pain, burning, or acroparesthesia in the hands or feet. The presence of Fabry disease was defined by abnormal alpha-galactosidase A activity in males or alpha-galactosidase gene (GLA) mutation in females. Among 214 patients (110 males), 84.1% had bilateral limb pain and 31.8% had unilateral limb pain recorded at some time point; 61 (28.5%) patients had a positive family history possibly associated with Fabry disease. Alpha-galactosidase A activity was within the normal range in all 109 of the male patients tested. One female patient had a GLA mutation (C937G > T) and alpha-galactosidase A activity within the normal range. We did not find definitive evidence of Fabry disease in these children with a history of chronic recurrent unilateral or bilateral limb pain or acroparesthesia. The presence of chronic limb pain does not appear to be highly predictive of a diagnosis of Fabry disease in Russian children and adolescents, suggesting that key early signs and symptoms of Fabry disease are not specific to the disease. What is Known: • Signs and symptoms of Fabry disease are seen in children < 10 years of age; pain in the distal limbs is a common early symptom. What is New: • Fabry disease was not diagnosed in this population of Russian children with a history of chronic limb pain. • The presence of acroparesthesia or chronic limb pain does not appear to be highly predictive of a diagnosis of Fabry disease in Russian children and adolescents, suggesting that these early symptoms of Fabry disease are not specific to the disease.

Experimental investigation of the optical injection locking dynamics in single section quantum-dash Fabry-Pérot laser diode for packet based clock recovery applications

NARCIS (Netherlands)

Maldonado-Basilio, R.; Parra-Cetina, J.; Latkowski, S.; Calabretta, N.; Landais, P.

2012-01-01

An experimental study of the dynamics of a quantum-dash Fabry-Pérot passively mode-locked laser diode is presented. Firstly, the switching on and off characteristic times of the mode-locking mechanism with pulsed biasing current are assessed. Secondly, the locking and unlocking characteristic times

Kyoto Protocol: trade versus the environment

International Nuclear Information System (INIS)

Loose, H.

2001-01-01

Could the signatories to the Kyoto Protocol find themselves up against the WTO? This paper examines how the climate change agreement could conflict with trade rules, and shows that there are potentially serious conflicts in the interface between the WTO and the Kyoto Protocol. It argues for dialogue and debate before it is too late. (author)

Kyoto protocol: at last the agreement has been reached; Protocole de Kyoto: un accord enfin conclu

Energy Technology Data Exchange (ETDEWEB)

NONE

2001-07-01

After more than 3 years of negotiations, 180 countries agreed at Bonn on the application of the Kyoto protocol to fight the climatic warming. The main aspects of this agreement are discussed: the carbon wells, the tools of the pollution control for the developed countries and the financial help to the developing countries. (A.L.B.)

Metabolomic Discovery of Novel Urinary Galabiosylceramide Analogs as Fabry Disease Biomarkers

Science.gov (United States)

Boutin, Michel; Auray-Blais, Christiane

2015-03-01

Fabry disease is an X-linked, complex, multisystemic lysosomal storage disorder presenting marked phenotypic and genotypic variability among affected male and female patients. Glycosphingolipids, mainly globotriaosylceramide (Gb3) isoforms/analogs, globotriaosylsphingosine (lyso-Gb3) and analogs, as well as galabiosylceramide (Ga2) isoforms/analogs accumulate in the vascular endothelium, nerves, cardiomyocytes, renal glomerular and tubular epithelial cells, and biological fluids. The search for biomarkers reflecting disease severity and progression is still on-going. A metabolomic study using quadrupole time-of-flight mass spectrometry has revealed 22 galabiosylceramide isoforms/analogs in urine of untreated Fabry patients classified in seven groups according to their chemical structure: (1) Saturated fatty acid; (2) one extra double bond; (3) two extra double bonds; (4) hydroxylated saturated fatty acid; (5) hydroxylated fatty acid and one extra double bond; (6) hydrated sphingosine and hydroxylated fatty acid; (7) methylated amide linkage. Relative quantification of both Ga2 and Gb3 isoforms/analogs was performed. All these biomarkers are significantly more abundant in urine samples from untreated Fabry males compared with healthy male controls. A significant amount of Ga2 isoforms/analogs, accounting for 18% of all glycosphingolipids analyzed (Ga2 + Gb3 and respective isoforms/analogs), were present in urine of Fabry patients. Gb3 isoforms containing saturated fatty acids are the most abundant (60.9%) compared with 26.3% for Ga2. A comparison between Ga2 isoforms/analogs and their Gb3 counterparts also showed that the proportion of analogs with hydroxylated fatty acids is significantly greater for Ga2 (35.8%) compared with Gb3 (1.9%). These results suggest different biological pathways involved in the synthesis and/or degradation of Gb3 and Ga2 metabolites.

Pressure effects on some argon spectral lines belonging to the 3p54p-3p5nd (n=5-7) transitions

International Nuclear Information System (INIS)

Wolnikowski, J.; Wawrzynski, J.; Bielski, A.; Szudy, J.

1987-01-01

Low pressure broadening and shift of four spectral lines of argon: 518.7 nm (3p 5 4p-3p 5 5d'), 522.1 nm (3p 5 4p-3p 5 7d), 549.6 nm (3p 5 4p-3p 5 6d) and 603.2 nm (3p 5 4p-3p 5 5d) have been investigated by means of a Fabry-Perot interferometer. The values of the pressure broadening and shift coefficients for argon-argon, argon-neon and argon-helium interactions in the low-current glow discharge conditions are determined. For all lines in the pure argon a red shift and in the argon-neon and argon-helium mixtures a blue shift has been found. The results cannot be interpreted on the basis of the existing simple interaction potential models within the framework of the adiabatic impact broadening theory. (orig.)

Controllable coupling of distributed qubits within a microtoroidal cavity network

Science.gov (United States)

Hu, C.; Xia, Y.; Song, J.

2012-05-01

We propose a scheme to control the coupling between two arbitrary atoms scattered within a quantum network composed of microtoroidal cavities linked by a ring-fibre. The atom-atom effective couplings are induced by pairing of off-resonant Raman transitions. The couplings can be arbitrarily controlled by adjusting classical fields. Compared with the previous scheme [S.B. Zheng, C.P. Yang, F. Nori, Phys. Rev. A 82, 042327 (2010)], the present scheme uses microtoroidal cavities with higher coupling efficiency than Fabry-Perot cavities. Furthermore, the scheme is not only suitable for the short-fibre limit, but also for multiple fibre modes. The added fibre modes can play a positive role, especially when the coupling rate between cavity-mode and fibre-mode is not large. In addition, a wider frequency domain of fibre modes can be used in this scheme.

A pulsed single-frequency Nd:GGG/BaWO4 Raman laser

Science.gov (United States)

Liu, Zhaojun; Men, Shaojie; Cong, Zhenhua; Qin, Zengguang; Zhang, Xingyu; Zhang, Huaijin

2018-04-01

A single-frequency pulsed laser at 1178.3 nm was demonstrated in a crystalline Raman laser. A crystal combination of Nd:GGG and BaWO4 was selected to realize Raman conversion from a 1062.5 nm fundamental wave to a 1178.3 nm Stokes wave. An entangled cavity was specially designed to form an intracavity Raman configuration. Single-longitudinal-mode operation was realized by introducing two Fabry-Perot etalons into the Raman laser cavity. This laser operated at a pulse repetition rate of 50 Hz with 2 ms long envelopes containing micro pulses at a 30 kHz repetition rate. The highest output power was 41 mW with the micro pulse duration of 15 ns. The linewidth was measured to be less than 130 MHz.

A miniature fiber-optic temperature sensor based on a Fabry–Perot interferometer

International Nuclear Information System (INIS)

Rong, Qiangzhou; Sun, Hao; Qiao, Xueguang; Zhang, Jing; Hu, Manli; Feng, Zhongyao

2012-01-01

A miniature fiber Fabry–Perot interferometer (FFPI) for temperature measurement is proposed and demonstrated. The sensor consists of a section of single-mode fiber (SMF) tip coated with a thin film of polyvinyl alcohol (PVA) at the end of the fiber tip. A well-defined interference pattern is obtained as the result of the FFPI based on Fresnel reflection. The sensing head is extremely sensitive to ambient temperature, and provides a stable temperature sensitivity with a maximum value up to 173.5 pm °C −1 above 80 °C. This proposed sensor has advantages of low cost, ultra-compactness, a small degree of hysteresis and high stability. (paper)

Diode-pumped two-frequency lasers based on c-cut vanadate crystals

International Nuclear Information System (INIS)

Sirotkin, A A; Garnov, Sergei V; Zagumennyi, A I; Zavartsev, Yu D; Kutovoi, S A; Vlasov, V I; Shcherbakov, Ivan A

2009-01-01

The luminescent and lasing properties of the neo-dymium ion at the 4 F 3/2 - 4 I 11/2 transition in c-cut vanadate crystals (Nd:YVO 4 , Nd:GdVO 4 , and Nd:Gd 1-x Y x VO 4 ) are studied. Tuning of the laser radiation wavelength (Δλ = 5.4 nm) is demonstrated. Two-frequency laser schemes with the use of a Lyot filter, a Fabry-Perot etalon, and a Brewster prism as spectral selection elements are proposed and experimentally realised. Stable two-frequency lasing of a laser based on the c-cut Nd:GdVO 4 crystal was obtained in the cw, Q-switched (nanosecond pulses), and active acousto-optic mode-locked (picosecond pulses) regimes. (lasers)

Low frequency noise fiber delay stabilized laser with reduced sensitivity to acceleration

Science.gov (United States)

Argence, B.; Clivati, C.; Dournaux, J.-L.; Holleville, D.; Faure, B.; Lemonde, P.; Santarelli, G.

2017-11-01

Lasers with sub-hertz line-width and fractional frequency instability around 1×10-15 for 0.1 s to 10 s averaging time are currently realized by locking onto an ultra-stable Fabry-Perot cavity using the Pound-Drever-Hall method. This powerful method requires tight alignment of free space optical components, precise polarization adjustment and spatial mode matching. To circumvent these issues, we use an all-fiber Michelson interferometer with a long fiber spool as a frequency reference and a heterodyne detection technique with a fibered acousto optical modulator (AOM)1. At low Fourier frequencies, the frequency noise of our system is mainly limited by mechanical vibrations, an issue that has already been explored in the field of optoelectronic oscillators.2,3,4

FabryScan: a screening tool for early detection of Fabry disease

NARCIS (Netherlands)

Arning, Kathrin; Naleschinski, Dennis; Maag, Rainer; Biegstraaten, Marieke; Kropp, Peter; Lorenzen, Jürgen; Hollak, Carla E. M.; van Schaik, Ivo N.; Harten, Pontus; Zeuner, Rainald A.; Binder, Andreas; Baron, Ralf

2012-01-01

Fabry disease, an X-linked lipid storage disorder, is associated early morbidity and mortality. Since enzyme replacement therapy is available, accurate detection of unrecognized cases is important. Characteristic early symptoms are recurrent episodes of burning and lancinating pain in the distal

Embedded fiber optic ultrasonic sensors and generators

Science.gov (United States)

Dorighi, John F.; Krishnaswamy, Sridhar; Achenbach, Jan D.

1995-04-01

Ultrasonic sensors and generators based on fiber-optic systems are described. It is shown that intrinsic fiber optic Fabry-Perot ultrasound sensors that are embedded in a structure can be stabilized by actively tuning the laser frequency. The need for this method of stabilization is demonstrated by detecting piezoelectric transducer-generated ultrasonic pulses in the presence of low frequency dynamic strains that are intentionally induced to cause sensor drift. The actively stabilized embedded fiber optic Fabry-Perot sensor is also shown to have sufficient sensitivity to detect ultrasound that is generated in the interior of a structure by means of a high-power optical fiber that pipes energy from a pulsed laser to an embedded generator of ultrasound.

Affinement spectral dans les lasers à colorants pulsés.

Science.gov (United States)

Flamant, P

1978-03-15

Spectral narrowing in pulsed dye lasers is studied theoretically. Fabry-Perot etalons, gratings, and prisms are considered as tuning elements. Each one is characterized by a new parameter: the spectral width associated with a round trip in the laser cavity. Numerical examples show that depending on cavity parameters it is either the round-trip spectral width or the width due to beam divergence which limits the bandwidth of the laser emission. Instantaneous spectral narrowing is found to be proportional to the square root of the time elapsed after the laser onset when a Fabry-Perot etalon or grating is used. When a prism is set in the laser cavity the instantaneous narrowing is proportional to time.

The variable finesse locking technique

International Nuclear Information System (INIS)

Acernese, F; Al-Shourbagy, M

2006-01-01

Virgo is a power recycled Michelson interferometer, with 3 km long Fabry-Perot cavities in the arms. The locking of the interferometer has been obtained with an original lock acquisition technique. The main idea is to lock the instrument away from its working point. Lock is obtained by misaligning the power recycling mirror and detuning the Michelson from the dark fringe. In this way, a good fraction of light escapes through the antisymmetric port and the power build-up inside the recycling cavity is extremely low. The benefit is that all the degrees of freedom are controlled when they are almost decoupled, and the linewidth of the recycling cavity is large. The interferometer is then adiabatically brought on to the dark fringe. This technique is referred to as variable finesse, since the recycling cavity is considered as a variable finesse Fabry-Perot. This technique has been widely tested and allows us to reach the dark fringe in few minutes, in an essentially deterministic way

Miniature all-silica optical fiber pressure sensor with an ultrathin uniform diaphragm.

Science.gov (United States)

Wang, Wenhui; Wu, Nan; Tian, Ye; Niezrecki, Christopher; Wang, Xingwei

2010-04-26

This paper presents an all-silica miniature optical fiber pressure/acoustic sensor based on the Fabry-Perot (FP) interferometric principle. The endface of the etched optical fiber tip and silica thin diaphragm on it form the FP structure. The uniform and thin silica diaphragm was fabricated by etching away the silicon substrate from a commercial silicon wafer that has a thermal oxide layer. The thin film was directly thermally bonded to the endface of the optical fiber thus creating the Fabry-Perot cavity. Thin films with a thickness from 1microm to 3microm have been bonded successfully. The sensor shows good linearity and hysteresis during measurement. A sensor with 0.75 microm-thick diaphragm thinned by post silica etching was demonstrated to have a sensitivity of 11 nm/kPa. The new sensor has great potential to be used as a non-intrusive pressure sensor in a variety of sensing applications.

The Kyoto mechanisms and technological innovation

International Nuclear Information System (INIS)

Lund, Henrik

2006-01-01

Climate change response, including the implementation of the Kyoto targets as the first step, calls for technological innovation of future sustainable energy systems. Based on the Danish case, this paper evaluates the type of technological change necessary. During a period of 30 years, Denmark managed to stabilize primary energy supply, and CO 2 emissions decreased by 10%, during a period of 20 years. However, after the introduction of the Kyoto Mechanisms, Denmark has changed its strategy. Instead of continuing the domestic CO 2 emission controls, Denmark plans to buy CO 2 reductions in other countries. Consequently, the innovative technological development has changed. This paper evaluates the character of such change and makes preliminary recommendations for policies to encourage the use of the Kyoto Mechanisms as an acceleration of the necessary technological innovation. (author)

Is Kyoto Fatally Flawed? An Analysis with MacGEM

International Nuclear Information System (INIS)

Eyckmans, J.; Van Regemorter, D.; Van Steenberghe, V.

2002-06-01

In this paper we present some numerical simulations with the MacGEM model to evaluate the consequences of the recent Marrakesh agreements and the defection of the USA for the Kyoto Protocol. MacGEM is a global marginal abatement cost model for carbon emissions from fossil fuel use based on the GEM-E3-World general equilibrium. Nonparticipation of the USA causes the equilibrium carbon price in Annex B countries to fall by approximately 50% since an important share of permit demand falls out. Carbon sinks enhancement activities enable Parties to fulfil their reduction commitment at lower compliance costs and cause the equilibrium permit price to decrease by 40%. Finally, it is shown that the former Soviet Union and central European countries have substantial monopoly power in the Kyoto carbon permit market. We conclude that the recent accords have eroded completely the Kyoto Protocol's emission targets but that they have the merit to have saved the international climate change negotiation framework

Laser frequency stabilization and control of optical cavities with suspended mirrors for the VIRGO interferometric detector of gravitational waves

International Nuclear Information System (INIS)

Barsuglia, Matteo

1999-01-01

The VIRGO detector is an interferometer with 3 km Fabry-Perot cavities in the arms. It is aimed at the detection of gravitational radiation emitted by astrophysical sources. This thesis comprises two independent parts. The first part is devoted to the laser frequency stabilization. In the second one we present a study of a suspended cavity. We determine the impact of laser frequency fluctuations on the overall VIRGO sensitivity. We study the frequency stabilization of the interferometer considered as an ultra-stable standard and we evaluate the noise pertaining to different signals taken into consideration. A strategy of control is discussed. We then study the VIRGO mode-cleaner prototype, a 30 m suspended triangular cavity, for which we have developed a control in order to keep it locked. Finally, we characterize this cavity in terms of mode spectra, finesse and mechanical transfer functions. (author)

MEMS-based microspectrometer technologies for NIR and MIR wavelengths

International Nuclear Information System (INIS)

Schuler, Leo P; Milne, Jason S; Dell, John M; Faraone, Lorenzo

2009-01-01

Commercially manufactured near-infrared (NIR) instruments became available about 50 years ago. While they have been designed for laboratory use in a controlled environment and boast high performance, they are generally bulky, fragile and maintenance intensive, and therefore expensive to purchase and maintain. Micromachining is a powerful technique to fabricate micromechanical parts such as integrated circuits. It was perfected in the 1980s and led to the invention of micro electro mechanical systems (MEMSs). The three characteristic features of MEMS fabrication technologies are miniaturization, multiplicity and microelectronics. Combined, these features allow the batch production of compact and rugged devices with integrated intelligence. In order to build more compact, more rugged and less expensive NIR instruments, MEMS technology has been successfully integrated into a range of new devices. In the first part of this paper we discuss the UWA MEMS-based Fabry-Perot spectrometer, its design and issues to be solved. MEMS-based Fabry-Perot filters primarily isolate certain wavelengths by sweeping across an incident spectrum and the resulting monochromatic signal is detected by a broadband detector. In the second part, we discuss other microspectrometers including other Fabry-Perot spectrometer designs, time multiplexing devices and mixed time/space multiplexing devices. (topical review)

Climate change ratification of the Kyoto Protocol : clearing the air on the debate

International Nuclear Information System (INIS)

2002-01-01

The Kyoto Protocol on Climate Change would commit Canada to limit emissions of greenhouse gases to 6 per cent below 1990 levels by 2008-2012. The Canadian Chamber of Commerce has outlined the following 3 key prerequisites that the federal government should and will have in place before any decision on ratification is made: (1) a detailed plan for achieving the Kyoto reductions, (2) a detailed analysis of environmental and economic impacts associated with Kyoto implementation, and (3) consultations with all stakeholder and the Canadian public once the plan has been released. Currently, Canadian businesses are taking voluntary actions to reduce industrial sector emissions through programs such as the Canadian Industry Program for Energy Conservation. Between 1990 and 1999, industrial sector emissions fell by 6 per cent. However, it was emphasized that despite these efforts, the gap between Canada's Kyoto target and its current greenhouse gas emissions continues to grow because of population and economic growth and rising exports. At the current rate of growth, it is estimated that meeting the Kyoto target could cost the economy up to $30 billion in 2010. The paper also discusses the implementation of key flexibility mechanisms such as carbon sinks, Joint Implementation, the Clean Development Mechanism and credits for export of cleaner energy to the United States, a non-Kyoto country. It is argued that ratification of Kyoto could hurt investments and impact jobs in Canada by making Canadian industries uncompetitive relative to their American counterparts. It is emphasized that full participation by the Canadian public is required in adapting to major lifestyle changes to reduce the use of fossil fuels and other sources of greenhouse gases. In conclusion, the Canadian Chamber of Commerce does not believe that the Kyoto Protocol is the most effective and efficient way of moving forward on the climate change issue and recommends that the federal government develop a made

Enzyme Replacement Therapy for Fabry Disease

Directory of Open Access Journals (Sweden)

Maria Dolores Sanchez-Niño PhD

2016-11-01

Full Text Available Fabry disease is a rare X-linked disease caused by the deficiency of α-galactosidase that leads to the accumulation of abnormal glycolipid. Untreated patients develop potentially lethal complications by age 30 to 50 years. Enzyme replacement therapy is the current standard of therapy for Fabry disease. Two formulations of recombinant human α-galactosidase A (agalsidase are available in most markets: agalsidase-α and agalsidase-β, allowing a choice of therapy. However, the US Food and Drug Administration rejected the application for commercialization of agalsidase-α. The main difference between the 2 enzymes is the dose. The label dose for agalsidase-α is 0.2 mg/kg/2 weeks, while the dose for agalsidase-β is 1.0 mg/kg/2 weeks. Recent evidence suggests a dose-dependent effect of enzyme replacement therapy and agalsidase-β is 1.0 mg/kg/2 weeks, which has been shown to reduce the occurrence of hard end points (severe renal and cardiac events, stroke, and death. In addition, patients with Fabry disease who have developed tissue injury should receive coadjuvant tissue protective therapy, together with enzyme replacement therapy, to limit nonspecific progression of the tissue injury. It is likely that in the near future, additional oral drugs become available to treat Fabry disease, such as chaperones or substrate reduction therapy.

Global post-Kyoto scenario analyses at PSI

Energy Technology Data Exchange (ETDEWEB)

Kypreos, S [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

1999-08-01

Scenario analyses are described here using the Global MARKAL-Macro Trade (GMMT) model to study the economic implications of the Kyoto Protocol to the UN Convention on Climate change. Some conclusions are derived in terms of efficient implementations of the post-Kyoto extensions of the Protocol. (author) 2 figs., 5 refs.

Global post-Kyoto scenario analyses at PSI

International Nuclear Information System (INIS)

Kypreos, S.

1999-01-01

Scenario analyses are described here using the Global MARKAL-Macro Trade (GMMT) model to study the economic implications of the Kyoto Protocol to the UN Convention on Climate change. Some conclusions are derived in terms of efficient implementations of the post-Kyoto extensions of the Protocol. (author) 2 figs., 5 refs

Fabrication of 3D SiO x structures using patterned PMMA sacrificial layer

Science.gov (United States)

Li, Zhiqin; Xiang, Quan; Zheng, Mengjie; Bi, Kaixi; Chen, Yiqin; Chen, Keqiu; Duan, Huigao

2018-02-01

Three-dimensional (3D) nanofabrication based on electron-beam lithography (EBL) has drawn wide attention for various applications with its high patterning resolution and design flexibility. In this work, we present a bilayer EBL process to obtain 3D freestanding SiO x structures via the release of the bottom sacrificial layer. This new kind of bilayer process enables us to define various 3D freestanding SiO x structures with high resolution and low edge roughness. As a proof of concept for applications, metal-coated freestanding SiO x microplates with an underlying air gap were fabricated to form asymmetric Fabry-Perot resonators, which can be utilized for colorimetric refractive index sensing and thus also have application potential for biochemical detection, anti-counterfeiting and smart active nano-optical devices.

From Kyoto to Copenhagen: the carbon markets expansion

International Nuclear Information System (INIS)

Alberola, Emilie; Fages, Emmanuel

2009-01-01

The article examines the development of carbon markets in the world. Such markets are the main economic instrument of the international climate policy established by the Kyoto Protocol in 1997 and are being implemented by most industrialized countries. They are experimented by Europe since 2005 for industrial facilities and since 2008 by industrialized countries under Kyoto. The development of carbon markets will likely continue beyond 2012, when the Kyoto Protocol expires. Their expansion will be largely determined by the future international climate policy to be negotiated in Copenhagen in December 2009 and by the commitment of the largest economies like the United States. The authors describe the emergence of carbon markets, their basic principles and the experience of Kyoto and European markets. Then, they deal with the expected developments beyond 2012

Response of women with Fabry disease to enzyme replacement therapy: comparison with men, using data from FOS--the Fabry Outcome Survey

NARCIS (Netherlands)

Hughes, Derralynn A.; Barba Romero, Miguel-Ángel; Hollak, Carla E. M.; Giugliani, Roberto; Deegan, Patrick B.

2011-01-01

Fabry disease (α-galactosidase A deficiency) is an X-linked disorder. Women who are heterozygous for disease-causing mutations often manifest signs and symptoms of Fabry disease, but most studies of the effects of enzyme replacement therapy (ERT) have included only men. To date, no direct comparison

Affective and cognitive behavior in the alpha-galactosidase A deficient mouse model of Fabry disease.

Directory of Open Access Journals (Sweden)

Lukas Hofmann

Full Text Available Fabry disease is an X-linked inherited lysosomal storage disorder with intracellular accumulation of globotriaosylceramide (Gb3 due to α-galactosidase A (α-Gal A deficiency. Fabry patients frequently report of anxiety, depression, and impaired cognitive function. We characterized affective and cognitive phenotype of male mice with α-Gal A deficiency (Fabry KO and compared results with those of age-matched male wildtype (WT littermates. Young (3 months and old (≥ 18 months mice were tested in the naïve state and after i.pl. injection of complete Freund`s adjuvant (CFA as an inflammatory pain model. We used the elevated plus maze (EPM, the light-dark box (LDB and the open field test (OF to investigate anxiety-like behavior. The forced swim test (FST and Morris water maze (MWM were applied to assess depressive-like and learning behavior. The EPM test revealed no intergroup difference for anxiety-like behavior in naïve young and old Fabry KO mice compared to WT littermates, except for longer time spent in open arms of the EPM for young WT mice compared to young Fabry KO mice (p<0.05. After CFA injection, young Fabry KO mice showed increased anxiety-like behavior compared to young WT littermates (p<0.05 and naïve young Fabry KO mice (p<0.05 in the EPM as reflected by shorter time spent in EPM open arms. There were no relevant differences in the LDB and the OF test, except for longer time spent in the center zone of the OF by young WT mice compared to young Fabry KO mice (p<0.05. Complementary to this, depression-like and learning behavior were not different between genotypes and age-groups, except for the expectedly lower memory performance in older age-groups compared to young mice. Our results indicate that genetic influences on affective and cognitive symptoms in FD may be of subordinate relevance, drawing attention to potential influences of environmental and epigenetic factors.

The Massive Compound Cofre de Perote Shield Volcano: a Volcanological Oddity in the Eastern Mexican Volcanic Belt

Science.gov (United States)

Siebert, L.; Carrasco-Nunez, G.; Diaz-Castellon, R.; Rodriguez, J. L.

2007-12-01

Cofre de Perote volcano anchors the northern end of the easternmost of several volcanic chains orthogonal to the E-W trend of the Mexican Volcanic Belt (MVB). Its structure, geochemistry, and volcanic history diverge significantly from that of the large dominantly andesitic stratovolcanoes that have been the major focus of research efforts in the MVB. Andesitic-trachyandesitic to dacitic-trachydacitic effusive activity has predominated at Cofre de Perote, forming a massive low-angle compound shield volcano that dwarfs the more typical smaller shield volcanoes of the central and western MVB. The 4282-m-high volcano overlooking Xalapa, the capital city of the State of Veracruz, has a diameter of about 30 km and rises more than 3000 m above the coastal plain to the east. Repeated edifice collapse has left massive horseshoe-shaped scarps that truncate the eastern side of the edifice. Five major evolutionary stages characterize the growth of this compound volcano: 1) emplacement of a multiple-vent dome complex forming the basal structure of Cofre de Perote around 1.9-1.3 Ma; 2) construction of the basal part of the compound shield volcano from at least two main upper-edifice vents at about 400 ka; 3) effusion of the summit dome-like lavas through multiple vents at ca. 240 ka; 4) eruption of a large number of geochemically diverse, alkaline and calc-alkaline Pleistocene-to-Holocene monogenetic cones (likely related to regional volcanism) through the flanks of the Cofre de Perote edifice; 5) late-stage, large-volume edifice collapse on at least two occasions (ca. 40 ka and ca. 10 ka), producing long-runout debris avalanches that traveled to the east. An undated tephra layer from Cofre de Perote overlies deposits likely of the youngest collapse. Cofre de Perote is one of several volcanoes in the roughly N-S-trending chain that has undergone major edifice collapse. As with Citlaltepetl (Pico de Orizaba) and Las Cumbres volcanoes, Cofre de Perote was constructed at the

Survey of environmental radiation dose rates in Kyoto and Shiga prefectures, Japan

International Nuclear Information System (INIS)

Minamia, Kazuyuki; Shimo, Michikuni; Oka, Mitsuaki; Ejiri, Kazutaka; Sugino, Masato; Minato, Susumu; Hosoda, Masahiro; Yamada, Junya; Fukushi, Masahiro

2008-01-01

We have measured environmental radiation dose rates in several Prefectures, such as Ai chi Prefecture, Gifu Prefecture, and Mie Prefecture, in central Japan. Recently, we measured the environmental radiation dose rates in Kyoto and Shiga Prefectures that are also located in central Japan with a car-borne survey system. At the time of measurement, Kyoto Prefecture (area: 4,613 km 2 ) had a total of 36 districts, and Shiga Prefecture (area: 3,387 km 2 ) a total of 26. Terrestrial gamma ray dose rates and secondary cosmic ray dose rates were measured by a 2 inches ψ x 2 inches NaI(Tl) scintillation counter and a handy-type altimeter (GPS eTrex Legend by Gamin), respectively. The following factors were taken into consideration the shielding effect of the car body, the effect of the road pavement, radon progeny borne by precipitation, and increases in tunnels and near the walls. Terrestrial gamma ray dose rates in Kyoto and Shiga Prefectures were estimated to be 51.7 ± 6.0 n Gy/h (district average: 52.4 ± 4.7 n Gy/h), 52.2 ± 10.5 n Gy/h (district average: 51.9 ± 8.1 n Gy/h), respectively. Secondary cosmic ray dose rates in Kyoto and Shiga Prefectures were 30.0 ± 0.6 n Gy/h (district average: 29.9 ±0.3 n Gy/h), 30.1 ± 0.3 n Gy/h (district average: 30.0 ± 0.2 n Gy/h), respectively. The environmental radiation dose rates due to the sum dose rates of terrestrial gamma ray and secondary cosmic ray in Kyoto and Shiga Prefectures were 81.7 ± 6.2 n Gy/h (district average: 82.3 ± 4.8 n Gy/h), 82.3 ± 10.6 n Gy/h (district average: 82.0 ± 8.1 n Gy/h), respectively. We confirmed that the environmental radiation dose rates in Kyoto and Shiga Prefectures mainly depended on the change of the terrestrial gamma ray dose rates, since the secondary cosmic ray dose rates had little change. Therefore, radiation dose-rate maps of the terrestrial gamma rays as well as maps of the environmental radiation dose-rate were drawn. (author)

Past and Future of the Kyoto Protocol. Final report

International Nuclear Information System (INIS)

Wijen, F.; Zoeteman, K.

2004-01-01

The present report reflects findings from a study on the realization of and prospects for the Kyoto Protocol. The purpose of the study was (1) to obtain insights into the factors that enabled the realization of the Kyoto Protocol, in particular the interactions among major parties involved; (2) to assess the future opportunities and threats of the Kyoto Protocol, in particular against the backdrop of an increasingly globalised world. The study was conducted from February up to December 2003 by (a) reviewing the literature, especially publications on the negotiation history of the Kyoto process, the social interactions enabling the realization of the Protocol, analyses of strengths and weaknesses, and future climate regimes; (b) conducting a series of interviews with representatives from government, academia, non-governmental organisations, and business, who have been - directly or indirectly - involved in the Kyoto process; (c) internal discussions,brainstorming and analysing the Protocol's strengths and weaknesses, possible future scenarios (including policy options), and the management of a possible failure of the Kyoto Protocol. The present report reflects and integrates the different sources. The first section deals with the past and the present. It discusses how the Kyoto Protocol could be realized despite the divergent interests, reflects on its architecture, and analyses major strengths and weaknesses. In the second section, we present possible future scenarios. We explore how different combinations of domestic and international commitment provide possible realities that national government may face when crafting climate policy. The third section provides an in-depth analysis of the possible event that the Kyoto Protocol fails. We discuss its definition and policy implications. The final section is reserved for overall conclusions and policy recommendations

A Radio-Frequency-over-Fiber link for large-array radio astronomy applications

International Nuclear Information System (INIS)

Mena, J; Bandura, K; Cliche, J-F; Dobbs, M; Gilbert, A; Tang, Q Y

2013-01-01

A prototype 425-850 MHz Radio-Frequency-over-Fiber (RFoF) link for the Canadian Hydrogen Intensity Mapping Experiment (CHIME) is presented. The design is based on a directly modulated Fabry-Perot (FP) laser, operating at ambient temperature, and a single-mode fiber. The dynamic performance, gain stability, and phase stability of the RFoF link are characterized. Tests on a two-element interferometer built at the Dominion Radio Astrophysical Observatory for CHIME prototyping demonstrate that RFoF can be successfully used as a cost-effective solution for analog signal transport on the CHIME telescope and other large-array radio astronomy applications

Surface modes at metallic an photonic crystal interfaces

Energy Technology Data Exchange (ETDEWEB)

Dai, Weitao [Iowa State Univ., Ames, IA (United States)

2009-01-01

on this picture, they deduced naturally that when surface plasmons momentum-matching condition is satisfied, the surface plasmons are excited sufficiently and the transmission reaches its peak. I present a new theory from first principles to explain EOT through one-dimensional periodic subwavelength metallic slits in this thesis. This theory can also be extended to 2D hole arrays. I define the incident wavelengths that satisfy the momentum-matching condition as surface resonant wavelengths. I proved analytically that the transmission is actually zero at the surface resonant wavelengths. The correct logic is: When the momentum-matching condition is satisfied, the surface plasmons excited by each slit interfere constructively with each other, the total surface plasmons will go to infinity. But the law of nature forbids the infinity. The only solution is the surface plasmon excited by one slit is zero and all the energy is reflected. In my theory, the term corresponding to surface plasmons appear explicitly in the equations. So it confirms the importance of surface plasmons without any doubt. The theory divides the transmission process into two steps: energy collection process along the input surface and the propagation process in the slits. In the first process, the surface plasmons collect the energy along the input surface and carry them to the slits. This process happens efficiently at any wavelength other than the surface resonant wavelengths. So EOT can happen at almost any wavelength. After the energy enter the slits, the Fabry-Perot interference between the input and output surface decides how much energy is emitted from the slits. So the EOT wavelengths are decided by the Fabry-Perot resonances. I also use my theory to explain the data in literatures. The transmission spectra through 1D slits or 2D hole arrays in literatures agree with my theory very well. The new theory can explain a lot of experimental results published recently, such as the transmission

Kyoto global consensus report on Helicobacter pylori gastritis

NARCIS (Netherlands)

K. Sugano (Kentaro); J. Tack (Jan); E.J. Kuipers (Ernst); D.Y. Graham (David Y.); E. El-Omar; S. Miura (Soichiro); K. Haruma (Ken); M. Asaka (Masahiro); N. Uemura (Naomi); P. Malfertheiner

2015-01-01

textabstractObjective To present results of the Kyoto Global Consensus Meeting, which was convened to develop global consensus on (1) classification of chronic gastritis and duodenitis, (2) clinical distinction of dyspepsia caused by Helicobacter pylori from functional dyspepsia, (3) appropriate

Prevalence of Fabry disease in young patients with cryptogenic ischemic stroke.

Science.gov (United States)

Dubuc, Véronique; Moore, David F; Gioia, Laura C; Saposnik, Gustavo; Selchen, Daniel; Lanthier, Sylvain

2013-11-01

A German study diagnosed 4% of young cryptogenic ischemic stroke patients with Fabry disease, an X-linked lysosomal storage disease caused by mutations in the alpha-galactosidase A (α-GAL-A) gene resulting in an accumulation of glycosphingolipids. A lower prevalence was found in other geographic regions. To determine the prevalence of Fabry disease in a Canadian population of young cryptogenic ischemic stroke patients. Patients with cryptogenic ischemic stroke at age 16-55 were retrospectively identified in our institutional stroke database and underwent a focused clinical evaluation. We sequenced the α-GAL-A gene and measured the levels of blood globotriaosylsphingosine in subjects with mutations of undetermined pathogenicity. Fabry disease was diagnosed in patients with pathogenic mutations or increased levels of blood globotriaosylsphingosine. Ninety-three of 100 study subjects had normal α-GAL-A gene polymorphisms. Seven had mutations of undetermined pathogenicity, including one with increased globotriaosylsphingosine (prevalence, 1%; 95% confidence interval, ischemic stroke presentation as the first clinical manifestation of Fabry disease. Both Fabry patients experienced recurrent ischemic stroke. Fabry disease accounts for a small proportion of young Canadians with cryptogenic ischemic stroke. Identification of Fabry biomarkers remains a research priority to delineate stroke patients disserving routine screening. Copyright © 2013 National Stroke Association. Published by Elsevier Inc. All rights reserved.

Substrate reduction augments the efficacy of enzyme therapy in a mouse model of Fabry disease.

Directory of Open Access Journals (Sweden)

John Marshall

Full Text Available Fabry disease is an X-linked glycosphingolipid storage disorder caused by a deficiency in the activity of the lysosomal hydrolase α-galactosidase A (α-gal. This deficiency results in accumulation of the glycosphingolipid globotriaosylceramide (GL-3 in lysosomes. Endothelial cell storage of GL-3 frequently leads to kidney dysfunction, cardiac and cerebrovascular disease. The current treatment for Fabry disease is through infusions of recombinant α-gal (enzyme-replacement therapy; ERT. Although ERT can markedly reduce the lysosomal burden of GL-3 in endothelial cells, variability is seen in the clearance from several other cell types. This suggests that alternative and adjuvant therapies may be desirable. Use of glucosylceramide synthase inhibitors to abate the biosynthesis of glycosphingolipids (substrate reduction therapy, SRT has been shown to be effective at reducing substrate levels in the related glycosphingolipidosis, Gaucher disease. Here, we show that such an inhibitor (eliglustat tartrate, Genz-112638 was effective at lowering GL-3 accumulation in a mouse model of Fabry disease. Relative efficacy of SRT and ERT at reducing GL-3 levels in Fabry mouse tissues differed with SRT being more effective in the kidney, and ERT more efficacious in the heart and liver. Combination therapy with ERT and SRT provided the most complete clearance of GL-3 from all the tissues. Furthermore, treatment normalized urine volume and uromodulin levels and significantly delayed the loss of a nociceptive response. The differential efficacies of SRT and ERT in the different tissues indicate that the combination approach is both additive and complementary suggesting the possibility of an improved therapeutic paradigm in the management of Fabry disease.

Magnetic resonance spectroscopy in patients with Fabry and Gaucher disease

Energy Technology Data Exchange (ETDEWEB)

Gruber, S., E-mail: stephan@nmr.at [Department of Radiology, MR-Centre of Excellence, Medical University of Vienna, Waehringer Guertel 18-20, A-1090 Vienna (Austria); Bogner, W. [Department of Radiology, MR-Centre of Excellence, Medical University of Vienna, Waehringer Guertel 18-20, A-1090 Vienna (Austria); Stadlbauer, A. [MR Physics Group, Department of Radiology, Landesklinikum St. Poelten (Austria); Krssak, M. [Department of Radiology, MR-Centre of Excellence, Medical University of Vienna, Waehringer Guertel 18-20, A-1090 Vienna (Austria); Bodamer, O. [Department of Pediatrics, Medical University of Vienna (Austria)

2011-08-15

Objective: Fabry and Gaucher diseases are rare progressive inherited disorders of glycosphingolipid metabolism that affect multiple organ systems. The aim of this study was to investigate evidence for metabolic changes in the central nervous system involvement using proton magnetic resonance spectroscopic imaging. Methods: Seven Fabry and eight Gaucher patients were included into this study. A two-dimensional, spectroscopic imaging method with an ultra-short echo-time of 11 ms was used at a 3 T whole body magnet. Absolute metabolic values were retrieved using internal water scaling. Results were compared, with sex- and age-matched controls. Results: In contrast to previous findings, absolute and relative metabolite values of N-acetyl-aspartate (NAA) or NAA/Creatine (Cr), Cr, Choline (Cho) or Cho/Cr and myo-Inositol (mI) or mI/Cr revealed no, differences between Fabry and Gaucher Type 1 (GD1) patients and controls. Average values were, 10.22, 6.32, 2.15 and 5.39 mMol/kg wet weight for NAA, Cr, Cho and mI, respectively. In this study, we found significantly decreasing NAA/Cho with increasing age in all three groups (Fabry, GD1, patients and healthy controls) (between 5 and 8% per decade). Conclusions: There were no changes of the quantified metabolites detected by MRS in normal appearing white matter. This study shows the importance of sex- and age-matched controls.

Magnetic resonance spectroscopy in patients with Fabry and Gaucher disease

International Nuclear Information System (INIS)

Gruber, S.; Bogner, W.; Stadlbauer, A.; Krssak, M.; Bodamer, O.

2011-01-01

Objective: Fabry and Gaucher diseases are rare progressive inherited disorders of glycosphingolipid metabolism that affect multiple organ systems. The aim of this study was to investigate evidence for metabolic changes in the central nervous system involvement using proton magnetic resonance spectroscopic imaging. Methods: Seven Fabry and eight Gaucher patients were included into this study. A two-dimensional, spectroscopic imaging method with an ultra-short echo-time of 11 ms was used at a 3 T whole body magnet. Absolute metabolic values were retrieved using internal water scaling. Results were compared, with sex- and age-matched controls. Results: In contrast to previous findings, absolute and relative metabolite values of N-acetyl-aspartate (NAA) or NAA/Creatine (Cr), Cr, Choline (Cho) or Cho/Cr and myo-Inositol (mI) or mI/Cr revealed no, differences between Fabry and Gaucher Type 1 (GD1) patients and controls. Average values were, 10.22, 6.32, 2.15 and 5.39 mMol/kg wet weight for NAA, Cr, Cho and mI, respectively. In this study, we found significantly decreasing NAA/Cho with increasing age in all three groups (Fabry, GD1, patients and healthy controls) (between 5 and 8% per decade). Conclusions: There were no changes of the quantified metabolites detected by MRS in normal appearing white matter. This study shows the importance of sex- and age-matched controls.

Fabry disease in children

DEFF Research Database (Denmark)

Borgwardt, Line Gutte; Feldt-Rasmussen, U; Rasmussen, Aase Krogh

2013-01-01

retrospective cohort study of 10 children (9-16 years at baseline), who underwent regular systematic investigations for 1-8 years after initiation of ERT with agalsidase-beta (Fabryzyme®, Genzyme). Ophthalmological, echocardiographic abnormalities and hypohidrosis were found at baseline and during the follow......Fabry disease is a rare, multiorgan disease. The most serious complications involve the kidney, brain and heart. This study aims to assess the effect of enzyme replacement therapy (ERT) using agalsidase-beta in children with Fabry disease. We carried out a nationwide, descriptive and observational......-up period. Serious kidney, heart or brain involvement had not developed at the last follow-up examination. For the majority of the patients improvements were found concerning headache, acroparaesthesias and gastrointestinal pain during the follow-up period. The level of energy and physical activity also...

Bulk phonon scattering in perturbed quasi-3D multichannel crystallographic waveguide

Energy Technology Data Exchange (ETDEWEB)

Rabia, M S [Laboratoire de Mecanique des Structures et Energetique, Departement de Genie Mecanique, Faculte du Genie de la Construction, Universite M. Mammeri, Tizi-Ouzou 15000 (Algeria)], E-mail: m2msr@yahoo.fr

2008-11-19

In the present paper, we concentrate on the influence of local defects on scattering properties of elastic waves in perturbed crystalline quasi-three-dimensional nanostructures in the harmonic approximation. Our model consists of three infinite atomic planes, assimilated into a perfect waveguide in which different distributions of scatterers (or defects) are inserted in the bulk. We have investigated phonon transmission and conductance for three bulk defect configurations. The numerical treatment of the problem, based on the Landauer approach, resorts to the matching method initially employed for the study of surface localized phonons and resonances. We present a detailed study of the defect-induced fluctuations in the transmission spectra. These fluctuations can be related to Fano resonances and Fabry-Perot oscillations. The first is due to the coupling between localized defect states and the perfect waveguide propagating modes whereas the latter results from the interference between incidental and reflected waves. Numerical results reveal the intimate relation between transmission spectra and localized impurity states and provide a basis for the understanding of conductance spectroscopy experiments in disordered mesoscopic systems.

High-Risk Screening for Fabry Disease: Analysis by Tandem Mass Spectrometry of Globotriaosylceramide (Gb3 ) in Urine Collected on Filter Paper.

Science.gov (United States)

Auray-Blais, Christiane; Lavoie, Pamela; Boutin, Michel; Abaoui, Mona

2017-04-06

Fabry disease is a complex, panethnic lysosomal storage disorder. It is characterized by the accumulation of glycosphingolipids in tissues, organs, the vascular endothelium, and biological fluids. The reported incidence in different populations is quite variable, ranging from 1:1400 to 1:117,000. Its complexity lies in the marked genotypic and phenotypic heterogeneity. Despite the fact that it is an X-linked disease, more than 600 mutations affect both males and females. In fact, some females may be affected as severely as males. The purpose of this protocol is to focus on the high-risk screening of patients who might have Fabry disease using a simple, rapid, non-invasive high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) method for urinary globotriaosylceramide (Gb 3 ) analysis. Urine filter paper samples are easily collected at home by patients and sent by regular mail. This method has been successfully used for high-risk screening of patients with ophthalmologic manifestations and in an on-going study for high-risk screening of Fabry disease in patients with chronic kidney diseases. © 2017 by John Wiley & Sons, Inc. Copyright © 2017 John Wiley & Sons, Inc.

355nm Photon-Recycled Fringe Imager for HSRL, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — The proposed work is to develop a high-efficiency aircraft-qualified Fabry-Perot-based interferometer for the High Spectral Resolution LIDAR (HSRL). Through this...

Optical metrology techniques for dimensional stability measurements

NARCIS (Netherlands)

Ellis, Jonathan David

2010-01-01

This thesis work is optical metrology techniques to determine material stability. In addition to displacement interferometry, topics such as periodic nonlinearity, Fabry-Perot interferometry, refractometry, and laser stabilization are covered.

Real-time trace gas sensor using a multimode diode laser and multiple-line integrated cavity enhanced absorption spectroscopy.

Science.gov (United States)

Karpf, Andreas; Rao, Gottipaty N

2015-07-01

We describe and demonstrate a highly sensitive trace gas sensor based on a simplified design that is capable of measuring sub-ppb concentrations of NO2 in tens of milliseconds. The sensor makes use of a relatively inexpensive Fabry-Perot diode laser to conduct off-axis cavity enhanced spectroscopy. The broad frequency range of a multimode Fabry-Perot diode laser spans a large number of absorption lines, thereby removing the need for a single-frequency tunable laser source. The use of cavity enhanced absorption spectroscopy enhances the sensitivity of the sensor by providing a pathlength on the order of 1 km in a small volume. Off-axis alignment excites a large number of cavity modes simultaneously, thereby reducing the sensor's susceptibility to vibration. Multiple-line integrated absorption spectroscopy (where one integrates the absorption spectra over a large number of rovibronic transitions of the molecular species) further improves the sensitivity of detection. Relatively high laser power (∼400  mW) is used to compensate for the low coupling efficiency of a broad linewidth laser to the optical cavity. The approach was demonstrated using a 407 nm diode laser to detect trace quantities of NO2 in zero air. Sensitivities of 750 ppt, 110 ppt, and 65 ppt were achieved using integration times of 50 ms, 5 s, and 20 s respectively.

An embeddable optical strain gauge based on a buckled beam.

Science.gov (United States)

Du, Yang; Chen, Yizheng; Zhu, Chen; Zhuang, Yiyang; Huang, Jie

2017-11-01

We report, for the first time, a low cost, compact, and novel mechanically designed extrinsic Fabry-Perot interferometer (EFPI)-based optical fiber sensor with a strain amplification mechanism for strain measurement. The fundamental design principle includes a buckled beam with a coated gold layer, mounted on two grips. A Fabry-Perot cavity is produced between the buckled beam and the endface of a single mode fiber (SMF). A ceramic ferrule is applied for supporting and orienting the SMF. The principal sensor elements are packaged and protected by two designed metal shells. The midpoint of the buckled beam will experience a deflection vertically when the beam is subjected to a horizontally/axially compressive displacement. It has been found that the vertical deflection of the beam at midpoint can be 6-17 times larger than the horizontal/axial displacement, which forms the basis of a strain amplification mechanism. The user-configurable buckling beam geometry-based strain amplification mechanism enables the strain sensor to achieve a wide range of strain measurement sensitivities. The designed EFPI was used to monitor shrinkage of a square brick of mortar. The strain was measured during the drying/curing stage. We envision that it could be a good strain sensor to be embedded in civil materials/structures under a harsh environment for a prolonged period of time.

An embeddable optical strain gauge based on a buckled beam

Science.gov (United States)

Du, Yang; Chen, Yizheng; Zhu, Chen; Zhuang, Yiyang; Huang, Jie

2017-11-01

We report, for the first time, a low cost, compact, and novel mechanically designed extrinsic Fabry-Perot interferometer (EFPI)-based optical fiber sensor with a strain amplification mechanism for strain measurement. The fundamental design principle includes a buckled beam with a coated gold layer, mounted on two grips. A Fabry-Perot cavity is produced between the buckled beam and the endface of a single mode fiber (SMF). A ceramic ferrule is applied for supporting and orienting the SMF. The principal sensor elements are packaged and protected by two designed metal shells. The midpoint of the buckled beam will experience a deflection vertically when the beam is subjected to a horizontally/axially compressive displacement. It has been found that the vertical deflection of the beam at midpoint can be 6-17 times larger than the horizontal/axial displacement, which forms the basis of a strain amplification mechanism. The user-configurable buckling beam geometry-based strain amplification mechanism enables the strain sensor to achieve a wide range of strain measurement sensitivities. The designed EFPI was used to monitor shrinkage of a square brick of mortar. The strain was measured during the drying/curing stage. We envision that it could be a good strain sensor to be embedded in civil materials/structures under a harsh environment for a prolonged period of time.

A 15-Year Perspective of the Fabry Outcome Survey

Directory of Open Access Journals (Sweden)

Roberto Giugliani MD, PhD

2016-09-01

Full Text Available The Fabry Outcome Survey (FOS is an international long-term observational registry sponsored by Shire for patients diagnosed with Fabry disease who are receiving or are candidates for therapy with agalsidase alfa (agalα. Established in 2001, FOS provides long-term data on agalα safety/efficacy and collects data on the natural history of Fabry disease, with the aim of improving clinical management. The FOS publications have helped establish prognostic and severity scores, defined the incidence of specific disease variants and implications for clinical management, described clinical manifestations in special populations, confirmed the high prevalence of cardiac morbidity, and demonstrated correlations between ocular changes and Fabry disease severity. These FOS data represent a rich resource with utility not only for description of natural history/therapeutic effects but also for exploratory hypothesis testing and generation of tools for diagnosis/management, with the potential to improve future patient outcomes.

The Kyoto mechanisms and technological innovation

DEFF Research Database (Denmark)

Lund, Henrik

2006-01-01

Climate change response, including the implementation of the Kyoto targets as the first step, calls for technological innovation of future sustainable energy systems. Based on the Danish case, this paper evaluates the type of technological change necessary. During a period of 30 years, Denmark...... countries. Consequently, the innovative technological development has changed. This paper evaluates the character of such change and makes preliminary recommendations for policies to encourage the use of the Kyoto Mechanisms as an acceleration of the necessary technological innovation....

Avascular necrosis of bilateral femoral heads in a patient with Fabry's disease.

LENUS (Irish Health Repository)

O'Neill, Francis

2012-07-13

The underlying cause of avascular necrosis (AVN) of the femoral head is often not apparent. We report the case of a 26 year old builder with a four month history of bilateral hip pain, and a diagnosis of bilateral femoral head avascular necrosis. Fabry\\'s disease was identified as the probable cause. Since 2001, enzyme replacement therapy for Fabry\\'s disease has become available, with a potential to influence the disease process, and this is of potential importance to clinicians treating AVN.

Kyoto : implications for utility regulation

International Nuclear Information System (INIS)

Dunsky, P.

2003-01-01

The author provided a historical perspective of energy use and the role of carbon in the western hemisphere by displaying a series of graphs showing carbon intensity of energy, carbon emissions from energy, and the long path to green power. The 1990s represented a decade of progress. Almost three times as much wind capacity as nuclear capacity was added worldwide in 2001. The main challenge for the 21st century will be to bring under-developed countries into the fold while perpetuating the economic and human progress of the twentieth century. It was emphasized that environmental damage caused by utilities must be reversed. The contemporary context for the Kyoto Protocol was reviewed. Canada's commitment under the Kyoto Protocol is to reduce greenhouse gas emissions by 6 per cent below 1990 levels. The challenge for utility regulators to meet this commitment was examined. The costs are not entirely excessive. Some of the regulatory issues were discussed, namely revising a broad rate making framework, cost recovery and others. The Kyoto compliance plan was also reviewed with reference to internal options, external options, identification of regulatory barriers, and consideration of greenhouse gas credit markets. figs

Contribution of inflammatory pathways to Fabry disease pathogenesis.

Science.gov (United States)

Rozenfeld, Paula; Feriozzi, Sandro

2017-11-01

Lysosomal storage diseases are usually considered to be pathologies in which the passive deposition of unwanted materials leads to functional changes in lysosomes. Lysosomal deposition of unmetabolized glycolipid substrates stimulates the activation of pathogenic cascades, including immunological processes, and particularly the activation of inflammation. In lysosomal storage diseases, the inflammatory response is continuously being activated because the stimulus cannot be eliminated. Consequently, inflammation becomes a chronic process. Lysosomes play a role in many steps of the immune response. Leukocyte perturbation and over-expression of immune molecules have been reported in Fabry disease. Innate immunity is activated by signals originating from dendritic cells via interactions between toll-like receptors and globotriaosylceramide (Gb3) and/or globotriaosylsphingosine (lyso-Gb3). Evidence indicates that these glycolipids can activate toll-like receptors, thus triggering inflammation and fibrosis cascades. In the kidney, Gb3 deposition is associated with the increased release of transforming growth factor beta and with epithelial-to-mesenchymal cell transition, leading to the over-expression of pro-fibrotic molecules and to renal fibrosis. Interstitial fibrosis is also a typical feature of heart involvement in Fabry disease. Endomyocardial biopsies show infiltration of lymphocytes and macrophages, suggesting a role for inflammation in causing tissue damage. Inflammation is present in all tissues and may be associated with other potentially pathologic processes such as apoptosis, impaired autophagy, and increases in pro-oxidative molecules, which could all contribute synergistically to tissue damage. In Fabry disease, the activation of chronic inflammation over time leads to organ damage. Therefore, enzyme replacement therapy must be started early, before this process becomes irreversible. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights

Fabry disease in light of recent review

International Nuclear Information System (INIS)

Uyama, Eiichiro

2008-01-01

Fabry disease is a lysosomal storage disorder that is caused by mutations in the gene encoding α-galactosidase A on Xq22.1. Typically hemizygous male patients exhibit classic phenotypes such as angiokeratoma, acroparesthesias, episodic pain ''crises,'' hypohidrosis, and whorl-shaped corneal opacities from childhood. However, during adulthood, they gradually develop kidney failure, heart disease, and strokes resulting in early death between 40 to 50 years of age. However, recent studies have indicated a high prevalence of disabling clinical symptoms in heterozygous females patients. Patients having the cardiac variant of Fabry's disease exhibit only left ventricular hypertrophy, while patients having the renal variant exhibit only kidney failure. Individuals affected by these variants show higher residual enzyme activity of α-galactosidase A than individuals affected by the classic form of Fabry's disease due to missense mutations of the GLA gene. The cerebrovascular involvement in Fabry disease is not rare in both adult hemizygotes and heterozygotes. Infarctions caused by the occlusions of small vessels involving mostly the vertebrobasilar region in approximately two-thirds of the cases, and that is associated with the deposition glycosphingolipids including GL-3 in the walls of these vessels. In Caucasian patients, elongated, ectatic, and tortuous vertebral and basilar arteries are frequently observed on MR angiography (MRA)s. Life-threatening megadolichobasilar anomaly with thrombosis has been identified in a large Hungarian family in which the family members share L16P mutation. On performing MRI, an increased signal intensity was observed in the pulvinar in T 1 -weighted images; this is the characteristic so-called ''pulvinar sign''. Enzyme replacement therapy has been approved in Japan since 2004 and 2007 for agalsidase β and agalsidase α, respectively. This treatment modestly improves the small-fiber neuropathy, hypohidrosis, hypertrophic cardiomyopathy

Enhancement of fiber-optic low-coherence Fabry-Pérot interferometer with ZnO ALD films

Science.gov (United States)

Hirsch, Marzena; Listewnik, Paulina; Jedrzejewska-Szczerska, Małgorzata

2018-04-01

In this paper investigation of the enhanced fiber-optic low coherence Fabry-Pérot interferometer with zinc oxide (ZnO) film deposited by atomic layer deposition (ALD) was presented. Model of the interferometer, which was constructed of single-mode optical fiber with applied ZnO ALD films, was built. The interferometer was also examined by means of experiment. Measurements were performed for both reflective and transmission modes, using wavelengths of 1300 nm and 1500 nm. The measurements with the air cavity showed the best performance in terms of a visibility of the interference signal can be achieved for small cavity lengths ( 50μm) in both configurations. Combined with the enhancement of reflectance of the interferometer mirrors due to the ALD film, proposed construction could be successfully applied in refractive index (RI) sensor that can operate with improved visibility of the signal even in 1.3-1.5 RI range as well as with small volume samples, as shown by the modeling.

Development of High Spectral Resolution Technique for Registration Quasielastic Light Scattering Spectra Including Rayleigh and Brillouin Scattering as a Diagnostic Tool in Materials Characterization

National Research Council Canada - National Science Library

Bairamov, Bakhysh

2004-01-01

...: As detailed in an on-line proposal the contractor will: 1) develop and build an optical device, fitted to a Fabry-Perot interferometer, to perform high-resolution quasieleastic light scattering spectroscopy; 2...

Surface-Emitting Distributed Feedback Terahertz Quantum-Cascade Lasers in Metal-Metal Waveguides

Science.gov (United States)

Kumar, Sushil; Williams, Benjamin S.; Qin, Qi; Lee, Alan W. M.; Hu, Qing; Reno, John L.

2007-01-01

Single-mode surface-emitting distributed feedback terahertz quantumcascade lasers operating around 2.9 THz are developed in metal-metal waveguides. A combination of techniques including precise control of phase of reflection at the facets, and u e of metal on the sidewalls to eliminate higher-order lateral modes allow robust single-mode operation over a range of approximately 0.35 THz. Single-lobed far-field radiation pattern is obtained using a pi phase-shift in center of the second-order Bragg grating. A grating device operating at 2.93 THz lased up to 149 K in pulsed mode and a temperature tuning of 19 .7 GHz was observed from 5 K to 147 K. The same device lased up to 78 K in continuous-wave (cw) mode emitting more than 6 m W of cw power at 5 K. ln general, maximum temperature of pulsed operation for grating devices was within a few Kelvin of that of multi-mode Fabry-Perot ridge lasers

Submission to the British Columbia government on the Kyoto Protocol

International Nuclear Information System (INIS)

2002-09-01

The Business Council provided its comments concerning the Kyoto Protocol and climate change to the government of British Columbia, recommending that a clear position be established quickly on the matter. The adopted position should also be disseminated broadly to allow stake holders sufficient time to prepare for the upcoming meetings of the Joint Ministers and First Ministers. The federal government has announced that the decision on whether to ratify the Kyoto Protocol will be made before the end of 2002, and this decision will have numerous effects on the people of British Columbia, businesses, workers, and consumers alike. The Business Council of British Columbia believes that the unique interests of the province can best be protected by a proactive approach. Actions plans are being prepared by several of the other provinces and territories, who have already stated their position concerning the Kyoto Protocol. The long-term risks of climate change for British Columbia have not been determined nor have the elements of a provincial approach. The following elements should be included in British Columbia's position on the Kyoto Protocol, according to the Business Council of British Columbia: (1) a credible and cost-effective implementation plan that does not unduly burden the province and other jurisdictions must be developed before Canada decides to ratify the Protocol. British Columbia should go on the record stating it does not support the ratification of the Kyoto Protocol in its present form. (2) the province should advocate for a national approach to climate change that can be achieved within a reasonable time frame, reflects the long-term nature of the problem, and is in agreement with the economic development objectives of British Columbia, (3) a plan detailing how the province intends to deal with the growth of greenhouse gas emissions should supplement and support the position of the province on the Kyoto Protocol. Consumers and business should be engaged

Kyoto PLUS: Efficient global emission trade for an effective future climate policy; Kyoto PLUS: Effizienter globaler Emissionshandel fuer eine zukuenftig wirksame Weltklimapolitik

Energy Technology Data Exchange (ETDEWEB)

Wicke, L. [Inst. fuer Umwelt-Management (IfUM) an der ESCP-EAP, Technische Univ. Berlin (Germany)

2007-08-15

The majority of climate protection experts believe that the Kyoto Protocol in its present version provides a basis for preventing the climate change from taking on disastrous dimensions. In the meantime however a mainstream of opinion has developed which advocates the establishment of a functioning global climate protection system for the post-Kyoto phase. Kyoto Plus, a global climate certification system, is a concept developed by the author of three expert opinions for the state of Baden-Wuerttemberg which takes the principles of the Kyoto Protocol a step forward while striving to eliminate its weaknesses and which has matured sufficiently to be put into practice. Systems of this or a similar kind could enable Germany to make a decisive additional contribution to global climate protection, as the author stated at the BT Hearing on 23 May 2007.

Acoustic resonances in two-dimensional radial sonic crystal shells

Energy Technology Data Exchange (ETDEWEB)

Torrent, Daniel; Sanchez-Dehesa, Jose, E-mail: jsdehesa@upvnet.upv.e [Wave Phenomena Group, Departamento de Ingenieria Electronica, Universidad Politecnica de Valencia, C/Camino de Vera s.n., E-46022 Valencia (Spain)

2010-07-15

Radial sonic crystals (RSC) are fluidlike structures infinitely periodic along the radial direction that verify the Bloch theorem and are possible only if certain specially designed acoustic metamaterials with mass density anisotropy can be engineered (see Torrent and Sanchez-Dehesa 2009 Phys. Rev. Lett. 103 064301). A comprehensive analysis of two-dimensional (2D) RSC shells is reported here. A given shell is in fact a circular slab with a central cavity. These finite crystal structures contain Fabry-Perot-like resonances and modes strongly localized at the central cavity. Semi-analytical expressions are developed to obtain the quality factors of the different resonances, their symmetry features and their excitation properties. The results reported here are completely general and can be extended to equivalent 3D spherical shells and to their photonic counterparts.

Clean Development Mechanism: Core of Kyoto Mechanism

Energy Technology Data Exchange (ETDEWEB)

Lee, Myung Kyun [United Nations Environment Programme (Denmark)

2000-06-01

Kyoto protocol is a foundation for achieving an ultimate goal of UNFCCC, which is to stabilizing greenhouse gas concentration in the air. The clean development system is a core element for successful implementation of Kyoto protocol with other Kyoto mechanisms. While UNFCCC requires a new paradigm changing to sustainable development considering demand and future environment from the past supply-oriented resource consumption, the clean development system will be used as a means of successful establishment of a new paradigm in 21st century. As environmental problem is integrated with economic problem and each country is thriving for securing its own economic benefit in the issue of environmental conservation, Korea should do its best to have both of global environmental conservation and economic benefit for its own. 1 tab.

Setting the stage: Outcome from Kyoto

International Nuclear Information System (INIS)

Manning, D.

1998-01-01

The commitment of the upstream oil and gas industry to implement actions to help Canadians become more efficient in their use of energy was discussed. The goals of the Rio Framework convention revolved around achieving greenhouse gas emissions reductions in the least costly manner. The industrial sector responded to that challenge through voluntary efforts to reduce greenhouse gases. However, from an industry perspective, the VCR (voluntary challenge registry) performance was inconsistent. While the upstream oil and gas industry participated aggressively, other industrial sectors, particularly the transportation sector, failed to participate. Progress was too slow and too late. The Third Conference of the Parties in Kyoto, resulted in a binding commitment of between 20 and 25 per cent per annum reduction for Canada. Emissions trading among developed countries is also included in the Kyoto Protocols. The speaker considered the reduction commitment of 20 to 25 per cent for Canada unrealistic, and suggested that the Kyoto protocol may be flawed, if only because so many of the details have not been spelled out. The importance of the roles of the federal and provincial governments in enforcing their consultative processes was emphasized. In the view of this speaker and that of the Canadian Association of Petroleum Producers, the biggest disappointments coming out of Kyoto, was the failure to gain meaningful involvement from the developing world. A global effort to reduce emissions cannot be achieved without the participation of the developing countries

Croatia energy planning and Kyoto Protocol

International Nuclear Information System (INIS)

Duic, Neven; Juretic, Franjo; Zeljko, Mladen; Bogdan, Z.

2005-01-01

Croatia as an Annex I country of the UN Framework Convention on Climate Change and a country that has pledged in the Annex B of the Kyoto Protocol to reduce its GHG emissions by 5% will have to envisage a new energy strategy. Compared to the energy consumption collapse in some transitional countries, Croatia has passed through a relatively short-term reduction of GHG emissions since 1990 because of higher energy efficiency of its pretransition economy. It is expected that in case of baseline scenario, it will breach the Kyoto target in 2003. Several scenarios of power generation are compared from the point of view of GHG emissions. The cost-effective scenario expects a mixture of coal and gas fired power plants to be built to satisfy the new demand and to replace the old power plants that are being decommissioned. More Kyoto friendly scenario envisages forcing the compliance with the Protocol with measures only in power generation sector by the construction of mainly zero emission generating capacity in the future, while decommissioning the old plants as planned, and is compared to the others from the GHG emissions point of view. The conclusion is that by measures tackling only power generation, it will not be possible to keep GHG emission under the Kyoto target level. The case of including the emissions from Croatian owned power plants in former Yugoslavia is also discussed

Biological dosimetry intercomparison exercise: an evaluation of Triage and routine mode results by robust methods

International Nuclear Information System (INIS)

Di Giorgio, M.; Vallerga, M.B.; Radl, A.; Taja, M.R.; Barquinero, J.F.; Seoane, A.; De Luca, J.; Guerrero Carvajal, Y.C.; Stuck Oliveira, M.S.; Valdivia, P.; García Lima, O.; Lamadrid, A.; González Mesa, J.; Romero Aguilera, I.; Mandina Cardoso, T.; Arceo Maldonado, C.; Espinoza, M.E.; Martínez López, W.; Lloyd, D.C.; Méndez Acuña, L.; Di Tomaso, M.V.; Roy, L.; Lindholm, C.; Romm, H.; Güçlü, I.

2011-01-01

Well-defined protocols and quality management standards are indispensable for biological dosimetry laboratories. Participation in periodic proficiency testing by interlaboratory comparisons is also required. This harmonization is essential if a cooperative network is used to respond to a mass casualty event. Here we present an international intercomparison based on dicentric chromosome analysis for dose assessment performed in the framework of the IAEA Regional Latin American RLA/9/054 Project. The exercise involved 14 laboratories, 8 from Latin America and 6 from Europe. The performance of each laboratory and the reproducibility of the exercise were evaluated using robust methods described in ISO standards. The study was based on the analysis of slides from samples irradiated with 0.75 (DI) and 2.5 Gy (DII). Laboratories were required to score the frequency of dicentrics and convert them to estimated doses, using their own dose-effect curves, after the analysis of 50 or 100 cells (triage mode) and after conventional scoring of 500 cells or 100 dicentrics. In the conventional scoring, at both doses, all reported frequencies were considered as satisfactory, and two reported doses were considered as questionable. The analysis of the data dispersion among the dicentric frequencies and among doses indicated a better reproducibility for estimated doses (15.6% for DI and 8.8% for DII) than for frequencies (24.4% for DI and 11.4% for DII), expressed by the coefficient of variation. In the two triage modes, although robust analysis classified some reported frequencies or doses as unsatisfactory or questionable, all estimated doses were in agreement with the accepted error of ±0.5 Gy. However, at the DI dose and for 50 scored cells, 5 out of the 14 reported confidence intervals that included zero dose and could be interpreted as false negatives. This improved with 100 cells, where only one confidence interval included zero dose. At the DII dose, all estimations fell within

Polymer waveguide Bragg grating Fabry–Perot filter using a nanoimprinting technique

International Nuclear Information System (INIS)

Binfeng, Yun; Guohua, Hu; Yiping, Cui

2014-01-01

A narrow band waveguide Fabry–Perot filter at 1550 nm, which is composed of two polymer waveguide Bragg gratings as reflectors, is presented. By using conventional lithography, a low-loss polymer channel waveguide was fabricated, and the submicron Bragg grating structure was transferred onto the waveguide surface using a nanoimprinting technique. The transmission spectrum of the device was measured, and the results show that there is a very narrow transmission peak, with a 3 dB bandwidth of 0.011 nm in the 0.38 nm rejection band of the waveguide Bragg grating. A quality factor of Q ≈ 1.41 × 10 5 is achieved. The insertion loss and the extinction ratio of the Fabry–Perot filter are about −12.5 dB and 17 dB, respectively. In addition, the measured transmission spectrum is in excellent accordance with the numerical simulation. (paper)

Carbon Sequestered, Carbon Displaced and the Kyoto Context

International Nuclear Information System (INIS)

Marland, G.; Schlamadinger, B.

1999-01-01

The integrated system that embraces forest management, forest products, and land-use change impacts the global carbon cycle - and hence the net emission of the greenhouse gas carbon dioxide - in four fundamental ways. Carbon is stored in living and dead biomass, carbon is stored in wood products and landfills, forest products substitute in the market place for products made from other materials, and forest harvests can be used wholly or partially to displace fossil fuels in the energy sector. Implementation of the Kyoto Protocol to the United Nations Framework Convention on Climate Change would result in the creation of international markets for carbon dioxide emissions credits, but the current Kyoto text does not treat all carbon identically. We have developed a carbon accounting model, GORCAM, to examine a variety of scenarios for land management and the production of forest products. In this paper we explore, for two simple scenarios of forest management, the carbon flows that occur and how these might be accounted for under the Kyoto text. The Kyoto protocol raises questions about what activities can result in emissions credits, which carbon reservoirs will be counted, who will receive the credits, and how much credit will be available? The Kyoto Protocol would sometimes give credits for carbon sequestered, but it would always give credits when fossil-fuel carbon dioxide emissions are displaced

[Clinical and histological findings in Fabry nephropathy].

Science.gov (United States)

Pieruzzi, Federico; Salerno, Fabio; Di Giacomo, Antonella; Torti, Giacomo; Ferrario, Franco; Pagni, Fabio; Stella, Andrea

2013-01-01

Fabry disease is a complex pathology, requiring a multidisciplinar approach both in the diagnostic workout and in the management of therapy. Clinical criteria able to predict its morbidity have not yet been found. The wide variability of clinical signs and symptoms requires an individual approach based on the single patient, in order to achieve an optimal management. Enzyme replacement therapy (ERT) has been introduced in the clinical setting for over ten years, but its ability to change the course of the disease has not yet been clearly proved. Recently the hypothesis that ERT may be ineffective in patients with severe organ involvement has emerged. The clinical course of Fabry disease is usually slower in eterozygous women than emizygous men, but can be frequently associated to severe organ failure and premature death in both cases. In this review we discuss the histological aspects of Fabry nephropathy in relation to diagnosis, prognosis, therapy and its effectiveness.

Developing the Digital Kyoto Collection in Education and Research.

Science.gov (United States)

Hill, Mark Anthony

2018-04-16

The Kyoto embryo collection was begun in 1961 by Dr. Hideo Nishimura. The collection has been continuously developed and currently contains over 44,000 human normal and abnormal specimens. Beginning online in 1997, the internet provided an opportunity to make embryos from the collection widely available for research and educational purposes (http://tiny.cc/Embryo). These embryonic development resources have been continuously published and available from that time until today. Published in Japanese as an Atlas of Embryonic Development. Published online as the Kyoto Human Embryo Visualization Project (http://atlas.cac.med.kyoto-u.ac.jp) and also as the Human Embryo Atlas (http://tiny.cc/Human_Embryo_Atlas). Published now electronically as a digital eBook (http://tiny.cc/Kyoto_Collection_eBook). This new digital format allows incorporation of whole embryo and histology manipulable images, labels, and a linked glossary. New imaging modalities of magnetic resonance imaging (MRI) and episcopic fluorescence image capture (EFIC) can also be easily displayed as animations. For research, the collection specimens and histological sections have been extensively studied and published in several hundred papers, discussed here and elsewhere in this special edition. I will also describe how the Kyoto collection will now form a major partner of a new international embryology research group, the Digital Embryology Consortium (https://human-embryology.org). The digital Kyoto collection will be made available for remote researcher access, analysis, and comparison with other collections allowing new research and educational applications. This work was presented at the 40th Anniversary Commemoration Symposium of the Congenital Anomaly Research Center, Graduate School of Medicine, Kyoto University, Japan, November, 2015. Anat Rec, 2018. © 2018 Wiley Periodicals, Inc. © 2018 Wiley Periodicals, Inc.

Globalization, transportation and Kyoto; Globalisatie, transport en Kyoto

Energy Technology Data Exchange (ETDEWEB)

Rodenburg, C.A.; Ubbels, B. [Afdeling Ruimtelijke Economie, Vrije Universiteit, Amsterdam (Netherlands); Nijkamp, P. [Economische Faculteit, Vrije Universiteit, Amsterdam (Netherlands)

2000-12-08

Globalization of the economy will probably coincide with more transport, as a result of which the environmental burden will increase. Thus, the Kyoto standards will be difficult to realize. Based on four economic scenarios with different levels of globalization insight is gained into the possible consequences of future developments (economic development, investment, consumption, (regional) specializations, and trade up to 2020) in the transportation sector, focusing on the Netherlands. Those developments have been made concrete by means of the Worldscan model, developed by the Netherlands Bureau for Economic Policy Analysis (CPB). 8 refs.

Observations of Superwinds in Dwarf Galaxies

Science.gov (United States)

Marlowe, A. T.; Heckman, T. M.; Wyse, R.; Schommer, R.

1993-12-01

Dwarf galaxies are important in developing our understanding of the formation and evolution of galaxies, and of the structure in the universe. The concept of supernova-driven mass outflows is a vital ingredient in theories of the structure and evolution of dwarfs galaxies. We have begun a detailed multi-waveband search for outflows in starbursting dwarf galaxies, and have obtained Fabry-Perot images and Echelle spectra of 20 nearby actively-star-forming dwarf galaxies. In about half the sample, the Fabry-Perot Hα images show loops and filaments with sizes of one to a few kpc. The Echelle spectra taken through the loops and filaments show kinematics consistent with expanding bubble-like structures. We describe these data, and present seven dwarfs in our sample that have the strongest evidence of outflows.

Ocean fertilization, carbon credits and the Kyoto Protocol

Science.gov (United States)

Westley, M. B.; Gnanadesikan, A.

2008-12-01

Commercial interest in ocean fertilization as a carbon sequestration tool was excited by the December 1997 agreement of the Kyoto Protocol to the United Nations Convention on Climate Change. The Protocol commits industrialized countries to caps on net greenhouse gas emissions and allows for various flexible mechanisms to achieve these caps in the most economically efficient manner possible, including trade in carbon credits from projects that reduce emissions or enhance sinks. The carbon market was valued at 64 billion in 2007, with the bulk of the trading (50 billion) taking place in the highly regulated European Union Emission Trading Scheme, which deals primarily in emission allowances in the energy sector. A much smaller amount, worth $265 million, was traded in the largely unregulated "voluntary" market (Capoor and Ambrosi 2008). As the voluntary market grows, so do calls for its regulation, with several efforts underway to set rules and standards for the sale of voluntary carbon credits using the Kyoto Protocol as a starting point. Four US-based companies and an Australian company currently seek to develop ocean fertilization technologies for the generation of carbon credits. We review these plans through the lens of the Kyoto Protocol and its flexible mechanisms, and examine whether and how ocean fertilization could generate tradable carbon credits. We note that at present, ocean sinks are not included in the Kyoto Protocol, and that furthermore, the Kyoto Protocol only addresses sources and sinks of greenhouse gases within national boundaries, making open-ocean fertilization projects a jurisdictional challenge. We discuss the negotiating history behind the limited inclusion of land use, land use change and forestry in the Kyoto Protocol and the controversy and eventual compromise concerning methodologies for terrestrial carbon accounting. We conclude that current technologies for measuring and monitoring carbon sequestration following ocean fertilization

NAFTA's shadow hangs over Kyoto's implementation

International Nuclear Information System (INIS)

Hornsby, D.J.; Summerlee, A.J.S.; Woodside, K.B.

2007-01-01

The Canadian government recently stated that it will not meet its Kyoto targets by the end of the first period in 2012, and instead proposed a twofold solution to reduce greenhouse gas emissions. The solutions involve the development of a Clean Air Act that will seek a 50 per cent reduction in emissions by 2050; and, participation in negotiations to determine the next steps for the Kyoto Protocol, post-2012. It was noted that as a ratified member of the Kyoto Protocol, Canada is still legally obligated to achieve its reduction requirements. However, as a co-signatory of the North American Free-Trade Agreement (NAFTA), Canada may be impeded from introducing and maintaining GHG reducing initiative since there are elements of NAFTA which may be used to block efforts that are considered discriminatory to trade. Chapter 11 of NAFTA assigns rights to Canadian, American and Mexican private investors to promote investment, ensure equal treatment and protect their investments against discrimination by NAFTA governments other than their own. These rights may challenge independent action by member states to reduce environmental risks. The authors emphasized that in order to avoid the possibility of legal challenges through Chapter 11 of NAFTA, it is important for the Canadian government to address various aspects of the flexibility mechanisms in the Kyoto Protocol. Three of these mechanisms were designed to reduce the financial burden and technological capacity issues associated with mitigating GHG emissions. These include emissions trading system, clean development mechanism, and joint implementation. The authors presented some policy recommendations to avoid future conflict. 26 refs

Active cancellation of residual amplitude modulation in a frequency-modulation based Fabry-Perot interferometer.

Science.gov (United States)

Yu, Yinan; Wang, Yicheng; Pratt, Jon R

2016-03-01

Residual amplitude modulation (RAM) is one of the most common noise sources known to degrade the sensitivity of frequency modulation spectroscopy. RAM can arise as a result of the temperature dependent birefringence of the modulator crystal, which causes the orientation of the crystal's optical axis to shift with respect to the polarization of the incident light with temperature. In the fiber-based optical interferometer used on the National Institute of Standards and Technology calculable capacitor, RAM degrades the measured laser frequency stability and correlates with the environmental temperature fluctuations. We have demonstrated a simple approach that cancels out excessive RAM due to polarization mismatch between the light and the optical axis of the crystal. The approach allows us to measure the frequency noise of a heterodyne beat between two lasers individually locked to different resonant modes of a cavity with an accuracy better than 0.5 ppm, which meets the requirement to further determine the longitudinal mode number of the cavity length. Also, this approach has substantially mitigated the temperature dependency of the measurements of the cavity length and consequently the capacitance.

Two-dimensional 'photon fluid': effective photon-photon interaction and physical realizations

International Nuclear Information System (INIS)

Chiao, R Y; Hansson, T H; Leinaas, J M; Viefers, S

2004-01-01

We describe a recently developed effective theory for atom-mediated photon-photon interactions in a two-dimensional 'photon fluid' confined to a Fabry-Perot resonator. The photons in the lowest longitudinal cavity mode will appear as massive bosons interacting via a renormalized delta-function potential with a strength determined by physical parameters such as the density of atoms and the detuning of the photons relative to the resonance frequency of the atoms. We discuss novel quantum phenomena for photons, such as Bose-Einstein condensation and bound state formation, as well as possible experimental scenarios based on Rydberg atoms in a microwave cavity, or alkali atoms in an optical cavity

Zeno dynamics in wave-packet diffraction spreading

Energy Technology Data Exchange (ETDEWEB)

Porras, Miguel A. [Departamento de Fisica Aplicada, Universidad Politecnica de Madrid, Rios Rosas 21, ES-28003 Madrid (Spain); Luis, Alfredo; Gonzalo, Isabel [Departamento de Optica, Facultad de Ciencias Fisicas, Universidad Complutense, ES-28040 Madrid (Spain); Sanz, Angel S. [Instituto de Fisica Fundamental-CSIC, Serrano 123, ES-28006 Madrid (Spain)

2011-11-15

We analyze a simple and feasible practical scheme displaying Zeno, anti-Zeno, and inverse-Zeno effects in the observation of wave-packet spreading caused by free evolution. The scheme is valid both in spatial diffraction of classical optical waves and in time diffraction of a quantum wave packet. In the optical realization, diffraction spreading is observed by placing slits between a light source and a light-power detector. We show that the occurrence of Zeno or anti-Zeno effects depends just on the frequency of observations between the source and detector. These effects are seen to be related to the diffraction mode theory in Fabry-Perot resonators.

G 2.4 + 1.4: a supernova remnant or ring nebula around a peculiar star

International Nuclear Information System (INIS)

Johnson, H.M.

1975-01-01

G2.4+1.4 is a probable nonthermal radio source and an optical nebula which appears to be a supernova remnant (SNR). It also contains an O vi sequence star of great excitation. We present new radiofrequency continuum and (nil) H 92α observations, optical spectroscopy, and Fabry-Perot scanner observations of the nebula. The object distance (5 kpc), origin of gas kinematics (SNR expansion), and mode of excitation of the gas (photoexcitation and/or shock wave) remain uncertain. We discuss the possible roles of the O vi star as ''runaway'' in a SNR, as a source of photoexcitation, and as an ejector of a ''counterfeit'' SNR

Flat acoustic lens by acoustic grating with curled slits

KAUST Repository

Peng, Pai; Xiao, Bingmu; Wu, Ying

2014-01-01

and well predicted by the theory. We demonstrate that despite the large impedance mismatch between the acoustic lens and the matrix, the intensity at the focal point is still high due to Fabry-Perot resonance.

Exploring the ancillary benefits of the Kyoto Protocol for air pollution in Europe

International Nuclear Information System (INIS)

Vuuren, D.P. van; Cofala, J.; Eerens, H.E.; Oostenrijk, R.; Heyes, C.; Klimont, Z.; Elzen, M.G.J. den; Amann, M.

2006-01-01

An integrated approach to climate change and regional air pollution can harvest considerable ancillary benefits in terms of environmental impacts and costs. This is because both problems are caused to a large extent by the same activity (fossil fuel combustion). Substantial ancillary benefits were found for regional air pollution (SO 2 , NO x , VOC and particulate matter) of implementing the Kyoto Protocol (intended to control greenhouse gas emissions) in Europe. For instance, while three different scenarios on Kyoto implementation were found to reduce European CO 2 emissions by 4-7%, they also reduced European emissions of SO 2 by 5-14% compared with a no Kyoto policies case. The magnitude of ancillary benefits depends on how flexible mechanisms and surplus emission allowances are used in meeting the Kyoto targets. The total cost savings for implementing current policies for regional air pollution of the Kyoto Protocol are of an order of 2.5-7 billion Euro. In all cases, this is in the order of half the costs of the climate policy (4-12 billion Euro). Using flexible mechanisms reduces emissions of air pollutants for Europe as a whole even further than domestic implementation (e.g. 10-14% versus 5% for SO 2 emissions), but the reductions are shifted from Western Europe to Central and Eastern Europe and Russia. The use of surplus emission allowances to achieve the Kyoto targets decreases the ancillary benefits, in particular for the latter group of countries (e.g. unprotected area against acidification increases from 1.3 to 1.7 million ha)

Kyoto University-National Taiwan University International Symposium "Social Cognitive Biology on Representation of Environment

OpenAIRE

Saiki, Jun

2016-01-01

Sponsored by Kyoto University, National Taiwan University; Cosponsored by Unit for Advanced Studies of the Human Mind, Kyoto University, Kokoro Research Center, Kyoto University, Supported by Supporting Program for InteRaction-based Initiative Team Studies (SPIRITS), Kyoto University

Management of radioactive liquid and solid wastes at the Research Reactor Institute, Kyoto University, (3)

International Nuclear Information System (INIS)

Tsutsui, Tenson; Shimoura, K.; Koyama, A.

1977-11-01

In this report, the management of radioactive liquid and solid wastes at the Research Reactor Institute, Kyoto University during past 6 years, from April in 1971 to March in 1977 are reviewed. (auth.)

Real-time dynamic calibration of a tunable frequency laser source using a Fabry-Pérot interferometer

Energy Technology Data Exchange (ETDEWEB)

Mandula, Gábor, E-mail: mandula.gabor@wigner.mta.hu; Kis, Zsolt; Lengyel, Krisztián [Wigner Research Centre for Physics of the Hungarian Academy of Sciences, Konkoly-Thege Miklós út 29-33, H-1121 Budapest (Hungary)

2015-12-15

We report on a method for real-time dynamic calibration of a tunable external cavity diode laser by using a partially mode-matched plano-concave Fabry-Pérot interferometer in reflection geometry. Wide range laser frequency scanning is carried out by piezo-driven tilting of a diffractive grating playing the role of a frequency selective mirror in the laser cavity. The grating tilting system has a considerable mechanical inertness, so static laser frequency calibration leads to false results. The proposed real-time dynamic calibration based on the identification of primary- and Gouy-effect type secondary interference peaks with known frequency and temporal history can be used for a wide scanning range (from 0.2 GHz to more than 1 GHz). A concave spherical mirror with a radius of R = 100 cm and a plain 1% transmitting mirror was used as a Fabry-Pérot interferometer with various resonator lengths to investigate and demonstrate real-time calibration procedures for two kinds of laser frequency scanning functions.

Taking advantage of the Kyoto mechanisms in the natural gas industry; Benefices des mecanismes de Kyoto pour l'industrie du gaz naturel

Energy Technology Data Exchange (ETDEWEB)

Janssen, J. [Institute for Economy and the environment at the University of St. Gallen, IWOe-HSG (Switzerland)

2000-07-01

The Kyoto Protocol has laid the basis of global markets for greenhouse gas emission reductions. By means of the Kyoto Mechanisms Joint Implementation, the Clean Development Mechanism and International Emissions Trading it will be possible to produce abroad and trade internationally the greenhouse gas emission reductions needed to satisfy cost-efficiently the respective demand of industrialized countries. The paper analyses options available in the natural gas sector for realizing Joint Implementation and Clean Development Mechanism projects. Furthermore, it examines strategies that might be economically viable for companies operating in the natural gas sector for taking advantage of the Kyoto Mechanisms. (author)

Changes in Ionic Conductance Signature of Nociceptive Neurons Underlying Fabry Disease Phenotype

Science.gov (United States)

Namer, Barbara; Ørstavik, Kirstin; Schmidt, Roland; Mair, Norbert; Kleggetveit, Inge Petter; Zeidler, Maximillian; Martha, Theresa; Jorum, Ellen; Schmelz, Martin; Kalpachidou, Theodora; Kress, Michaela; Langeslag, Michiel

2017-01-01

The first symptom arising in many Fabry patients is neuropathic pain due to changes in small myelinated and unmyelinated fibers in the periphery, which is subsequently followed by a loss of sensory perception. Here we studied changes in the peripheral nervous system of Fabry patients and a Fabry mouse model induced by deletion of α-galactosidase A (Gla−/0). The skin innervation of Gla−/0 mice resembles that of the human Fabry patients. In Fabry diseased humans and Gla−/0 mice, we observed similar sensory abnormalities, which were also observed in nerve fiber recordings in both patients and mice. Electrophysiological recordings of cultured Gla−/0 nociceptors revealed that the conductance of voltage-gated Na+ and Ca2+ currents was decreased in Gla−/0 nociceptors, whereas the activation of voltage-gated K+ currents was at more depolarized potentials. Conclusively, we have observed that reduced sensory perception due to small-fiber degeneration coincides with altered electrophysiological properties of sensory neurons. PMID:28769867

Changes in Ionic Conductance Signature of Nociceptive Neurons Underlying Fabry Disease Phenotype

Directory of Open Access Journals (Sweden)

Barbara Namer

2017-07-01

Full Text Available The first symptom arising in many Fabry patients is neuropathic pain due to changes in small myelinated and unmyelinated fibers in the periphery, which is subsequently followed by a loss of sensory perception. Here we studied changes in the peripheral nervous system of Fabry patients and a Fabry mouse model induced by deletion of α-galactosidase A (Gla−/0. The skin innervation of Gla−/0 mice resembles that of the human Fabry patients. In Fabry diseased humans and Gla−/0 mice, we observed similar sensory abnormalities, which were also observed in nerve fiber recordings in both patients and mice. Electrophysiological recordings of cultured Gla−/0 nociceptors revealed that the conductance of voltage-gated Na+ and Ca2+ currents was decreased in Gla−/0 nociceptors, whereas the activation of voltage-gated K+ currents was at more depolarized potentials. Conclusively, we have observed that reduced sensory perception due to small-fiber degeneration coincides with altered electrophysiological properties of sensory neurons.

Long-term enzyme replacement therapy is associated with reduced proteinuria and preserved proximal tubular function in women with Fabry disease

DEFF Research Database (Denmark)

Prabakaran, Thaneas; Birn, Henrik; Bibby, Bo M

2014-01-01

dysfunction in women with Fabry disease treated with ERT. METHODS: A retrospective, single centre, cohort study evaluated the long-term association between ERT, albuminuria and eGFR in 13 women with Fabry disease and mild renal involvement. In particular, we analysed the changes in the proteinuric profile...... to end-stage renal failure. In women with Fabry disease, accumulation of GL-3 in the glomerular podocytes and other renal cells induces progressive, proteinuric nephropathy, but not as severe as in men. Enzyme replacement therapy (ERT) with recombinant α-Gal A reduces cellular GL-3 deposits in podocytes...... in albuminuria was paralleled by a decrease in both glomerular and tubular urine protein markers. CONCLUSIONS: The data indicate that long-term ERT is associated with a reduction in albuminuria and glomerular and tubular urinary protein markers in women with Fabry disease and mild renal manifestations....

Estimating the size of the potential market for the Kyoto flexibility mechanisms

NARCIS (Netherlands)

Zhang, Zhong Xiang

1999-01-01

The Kyoto Protocol incorporates emissions trading, joint implementation and the clean development mechanism to help Annex I countries to meet their Kyoto targets at a lower overall cost. This paper aims to estimate the size of the potential market for all three flexibility mechanisms under the Kyoto

The marbles of Kyoto

International Nuclear Information System (INIS)

Jeucken, M.H.A.

2000-01-01

Reduction of greenhouse gases can result in considerable costs and benefits for businesses. Financial institutes (e.g. banking and assurance companies) can develop and provide financial products to support industry and businesses which have to meet environmental regulations as set in the Kyoto Protocol and national environmental regulations. 6 refs

Micro-structured optical fiber sensor for simultaneous measurement of temperature and refractive index

Science.gov (United States)

Liu, Ying-gang; Liu, Xin; Ma, Cheng-ju; Zhou, Yu-min

2018-03-01

Through using micro-machining method for optical fiber sensor, a kind of miniature, compact and composite structural all-fiber sensor is presented. Based on manufacturing two micro-holes with certain distance in ordinary single-mode fiber Bragg grating (FBG) by excimer laser processing technique, we fabricate a dual Fabry-Perot-FBG (FP-FBG) composite fiber interferometric sensor, which can be used in simultaneous measurement for liquid's refractive index (RI) and temperature change. Due to every micro-hole and the dual micro-holes in fiber acting as different Fabry-Perot (FP) cavities, this kind of sensor has not only different RI sensitivities but also different temperature sensitivities, which are corresponding to the wavelength shifts of the fine interference fringes and spectral envelope, respectively. The experimental results show that the spectral wavelength shift keep better linear response for temperature and RI change, so that we can select the higher temperature and RI sensitivities as well as the analyzed sensitivities of FBG to utilize them for constituting a sensitivity coefficients matrix. Finally, the variations of liquid's temperature and RI are detected effectively, and the resolutions can reach to 0.1 °C and 1.0 ×10-5 RIU. These characteristics are what other single-type sensors don't have, so that this kind of all-fiber dual FP-FBG composite fiber interferometric sensor can be used in extremely tiny liquid environment for measuring different physical quantities simultaneously.

Determination of an optimized Alq3 layer thickness in organic light-emitting diodes by using microcavity effects

International Nuclear Information System (INIS)

Jung, Boo-Young; Hwangbo, Chang-Kwon

2006-01-01

In this paper, an optical model of an organic light-emitting diode (OLED) based on the optical thin film theory is derived to calculate the output intensity of a small-molecule OLED. Two types of Alq 3 -based OLEDs are designed using the optical model and deposited to compare with the designed OLEDs. The optical model shows that the radiance of the OLED can be affected by the Fabry-Perot multiple beam interference effect, the two-beam interference effect, and the spontaneous emission spectrum of the emitting material. The measured spectral characteristics for the two types of OLEDs are found to be in good agreement with the simulation. The result suggests that the proposed optical model can be used for optimizing the architecture of small-molecule OLEDs.

Fabry disease and early stroke

DEFF Research Database (Denmark)

Feldt-Rasmussen, U

2011-01-01

Fabry disease, an X-linked lysosomal storage disorder, results from deficient activity of the enzyme a-galactosidase A. Affected males with the classic phoenotype have acroparaesthesias, hypohidrosis, and corneal opacities in childhood and develop renal failure, cardiac hypertrophy or strokes in ...

Fabry disease and early stroke

DEFF Research Database (Denmark)

Feldt-Rasmussen, U

2011-01-01

Fabry disease, an X-linked lysosomal storage disorder, results from deficient activity of the enzyme α-galactosidase A. Affected males with the classic phoenotype have acroparaesthesias, hypohidrosis, and corneal opacities in childhood and develop renal failure, cardiac hypertrophy or strokes in ...

Value of the CHA2DS2-VASc score and Fabry-specific score for predicting new-onset or recurrent stroke/TIA in Fabry disease patients without atrial fibrillation.

Science.gov (United States)

Liu, Dan; Hu, Kai; Schmidt, Marie; Müntze, Jonas; Maniuc, Octavian; Gensler, Daniel; Oder, Daniel; Salinger, Tim; Weidemann, Frank; Ertl, Georg; Frantz, Stefan; Wanner, Christoph; Nordbeck, Peter

2018-05-24

To evaluate potential risk factors for stroke or transient ischemic attacks (TIA) and to test the feasibility and efficacy of a Fabry-specific stroke risk score in Fabry disease (FD) patients without atrial fibrillation (AF). FD patients often experience cerebrovascular events (stroke/TIA) at young age. 159 genetically confirmed FD patients without AF (aged 40 ± 14 years, 42.1% male) were included, and risk factors for stroke/TIA events were determined. All patients were followed up over a median period of 60 (quartiles 35-90) months. The pre-defined primary outcomes included new-onset or recurrent stroke/TIA and all-cause death. Prior stroke/TIA (HR 19.97, P TIA in FD patients without AF. A Fabry-specific score was established based on above defined risk factors, proving somehow superior to the CHA 2 DS 2 -VASc score in predicting new-onset or recurrent stroke/TIA in this cohort (AUC 0.87 vs. 0.75, P = .199). Prior stroke/TIA, angiokeratoma, renal dysfunction, left ventricular hypertrophy, and global systolic dysfunction are independent risk factors for new-onset or recurrent stroke/TIA in FD patients without AF. It is feasible to predict new or recurrent cerebral events with the Fabry-specific score based on the above defined risk factors. Future studies are warranted to test if FD patients with high risk for new-onset or recurrent stroke/TIA, as defined by the Fabry-specific score (≥ 2 points), might benefit from antithrombotic therapy. Clinical trial registration HEAL-FABRY (evaluation of HEArt invoLvement in patients with FABRY disease, NCT03362164).

Autonomic skin responses in females with Fabry disease

DEFF Research Database (Denmark)

Møller, Anette Torvin; Bach, Flemming W.; Feldt-Rasmussen, Ulla

2009-01-01

Fabry disease is a genetic lysosomal disorder with dysfunction of the lysosomal enzyme alpha-galactosidase A causing accumulation of glycolipids in multiple organs including the nervous system and with neuropathy as a prominent manifestation. Neurological symptoms include pain and autonomic...... dysfunction. This study examined peripheral autonomic nerve function in 19 female patients with Fabry disease and 19 sex and age-matched controls by measuring (1) sweat production following acetylcholine challenge; (2) the sympathetically mediated vasoconstrictor responses to inspiratory gasp, stress...

Screening Fabry's disease in chronic kidney disease patients not on dialysis: a multicenter study.

Science.gov (United States)

Yeniçerioğlu, Yavuz; Akdam, Hakan; Dursun, Belda; Alp, Alper; Sağlam Eyiler, Funda; Akın, Davut; Gün, Yelda; Hüddam, Bülent; Batmazoğlu, Mehmet; Gibyeli Genek, Dilek; Pirinççi, Serhat; Ersoy, İsmail Rıfkı; Üzüm, Atilla; Soypaçacı, Zeki; Tanrısev, Mehmet; Çolak, Hülya; Demiral Sezer, Sibel; Bozkurt, Gökay; Akyıldız, Utku Oğan; Akyüz Ünsal, Ayşe İpek; Ünübol, Mustafa; Uslu, Meltem; Eryılmaz, Ufuk; Günel, Ceren; Meteoğlu, İbrahim; Yavaşoğlu, İrfan; Ünsal, Alparslan; Akar, Harun; Okyay, Pınar

2017-11-01

Fabry's disease is an X-linked inherited, rare, progressive, lysosomal storage disorder, affecting multiple organs due to the deficient activity of α-galactosidase A (α-Gal A) enzyme. The prevalence has been reported to be 0.15-1% in hemodialysis patients; however, the information on the prevalence in chronic kidney disease not on dialysis is lacking. This study aimed to determine the prevalence of Fabry's disease in chronic kidney disease. The patients older than 18 years, enclosing KDIGO 2012 chronic kidney disease definitions, not on dialysis, were enrolled. Dried blood spots on Guthrie papers were used to analyze α-Gal A enzyme and genetic analysis was performed in individuals with enzyme activity ≤1.2 μmol/L/h. A total of 1453 chronic kidney disease patients not on dialysis from seven clinics in Turkey were screened. The mean age of the study population was 59.3 ± 15.9 years. 45.6% of patients were female. The creatinine clearance of 77.3% of patients was below 60 mL/min/1.73 m 2 , 8.4% had proteinuria, and 2.5% had isolated microscopic hematuria. The mean value of patients' α-Gal A enzyme was detected as 2.93 ± 1.92 μmol/L/h. 152 patients had low levels of α-Gal A enzyme activity (≤1.2 μmol/L/h). In mutation analysis, A143T and D313Y variants were disclosed in three male patients. The prevalence of Fabry's disease in chronic kidney disease not on dialysis was found to be 0.2% (0.4% in male, 0.0% in female). Fabry's disease should be considered in the differential diagnosis of chronic kidney disease with unknown etiology even in the absence of symptoms and signs suggestive of Fabry's disease.

A polarisation modulation scheme for measuring vacuum magnetic birefringence with static fields

Energy Technology Data Exchange (ETDEWEB)

Zavattini, G.; Ejlli, A. [Universita di Ferrara, Dipt. di Fisica e Scienze della Terra (Italy); INFN, Sezione di Ferrara (Italy); Della Valle, F. [Universita di Trieste, Dipt. di Fisica, Trieste (Italy); INFN, Sezione di Trieste, TS (Italy); Ruoso, G. [INFN, Lab. Nazionali di Legnaro (Italy)

2016-05-15

A novel polarisation modulation scheme for polarimeters based on Fabry-Perot cavities is presented. The application to the measurement of the magnetic birefringence of vacuum with the HERA superconducting magnets in the ALPS-II configuration is discussed. (orig.)

Ultrafast all-optical clock recovery based on phase-only linear optical filtering

DEFF Research Database (Denmark)

Maram, Reza; Kong, Deming; Galili, Michael

2014-01-01

We report on a novel technique for all-optical clock recovery from RZ OOK data based on phase-only filtering, significantly enhancing the recovered clock quality and energy-efficiency compared to the use of a Fabry-Perot filter....

Growth of GaN micro/nanolaser arrays by chemical vapor deposition.

Science.gov (United States)

Liu, Haitao; Zhang, Hanlu; Dong, Lin; Zhang, Yingjiu; Pan, Caofeng

2016-09-02

Optically pumped ultraviolet lasing at room temperature based on GaN microwire arrays with Fabry-Perot cavities is demonstrated. GaN microwires have been grown perpendicularly on c-GaN/sapphire substrates through simple catalyst-free chemical vapor deposition. The GaN microwires are [0001] oriented single-crystal structures with hexagonal cross sections, each with a diameter of ∼1 μm and a length of ∼15 μm. A possible growth mechanism of the vertical GaN microwire arrays is proposed. Furthermore, we report room-temperature lasing in optically pumped GaN microwire arrays based on the Fabry-Perot cavity. Photoluminescence spectra exhibit lasing typically at 372 nm with an excitation threshold of 410 kW cm(-2). The result indicates that these aligned GaN microwire arrays may offer promising prospects for ultraviolet-emitting micro/nanodevices.

A new method for testing Newton's gravitational law

International Nuclear Information System (INIS)

Schurr, J.; Klein, N.; Meyer, H.; Piel, H.; Walesch, H.

1991-01-01

A new experimental method is reported for determining the gravitational force of a laboratory test mass on a Fabry-Perot microwave resonator. The resonator consists of two Fabry-Perot mirrors suspended as pendulums. Changes of 2·10 -11 m in the pendulum separation can be resolved as a shift of the resonance frequency of the resonator. This limit corresponds to an acceleration of 7·10 -11 m s -2 of one mirror with respect to the other. In a first experiment, the gravitational acceleration generated by a 125 kg test mass was measured as a function of distance in the range of 10 to 15 cm and tested Newton's gravitational law with an accuracy of 1%. No deviation is found. Furthermore, the gravitational constant G is determined with similar precision. (author) 5 refs., 2 figs

Fiber cavities with integrated mode matching optics.

Science.gov (United States)

Gulati, Gurpreet Kaur; Takahashi, Hiroki; Podoliak, Nina; Horak, Peter; Keller, Matthias

2017-07-17

In fiber based Fabry-Pérot Cavities (FFPCs), limited spatial mode matching between the cavity mode and input/output modes has been the main hindrance for many applications. We have demonstrated a versatile mode matching method for FFPCs. Our novel design employs an assembly of a graded-index and large core multimode fiber directly spliced to a single mode fiber. This all-fiber assembly transforms the propagating mode of the single mode fiber to match with the mode of a FFPC. As a result, we have measured a mode matching of 90% for a cavity length of ~400 μm. This is a significant improvement compared to conventional FFPCs coupled with just a single mode fiber, especially at long cavity lengths. Adjusting the parameters of the assembly, the fundamental cavity mode can be matched with the mode of almost any single mode fiber, making this approach highly versatile and integrable.

Remote Sensing and the Kyoto Protocol: A Workshop Summary

Science.gov (United States)

Rosenqvist, Ake; Imhoff, Marc; Milne, Anthony; Dobson, Craig

2000-01-01

The Kyoto Protocol to the United Nations Framework Convention on Climate Change contains quantified, legally binding commitments to limit or reduce greenhouse gas emissions to 1990 levels and allows carbon emissions to be balanced by carbon sinks represented by vegetation. The issue of using vegetation cover as an emission offset raises a debate about the adequacy of current remote sensing systems and data archives to both assess carbon stocks/sinks at 1990 levels, and monitor the current and future global status of those stocks. These concerns and the potential ratification of the Protocol among participating countries is stimulating policy debates and underscoring a need for the exchange of information between the international legal community and the remote sensing community. On October 20-22 1999, two working groups of the International Society for Photogrammetry and Remote Sensing (ISPRS) joined with the University of Michigan (Michigan, USA) to convene discussions on how remote sensing technology could contribute to the information requirements raised by implementation of, and compliance with, the Kyoto Protocol. The meeting originated as a joint effort between the Global Monitoring Working Group and the Radar Applications Working Group in Commission VII of the ISPRS, co-sponsored by the University of Michigan. Tile meeting was attended by representatives from national government agencies and international organizations and academic institutions. Some of the key themes addressed were: (1) legal aspects of transnational remote sensing in the context of the Kyoto Protocol; (2) a review of the current and future and remote sensing technologies that could be applied to the Kyoto Protocol; (3) identification of areas where additional research is needed in order to advance and align remote sensing technology with the requirements and expectations of the Protocol; and 94) the bureaucratic and research management approaches needed to align the remote sensing

Near-infrared tunable laser diode spectroscopy: an easy way for gas sensing

Science.gov (United States)

Larive, Marc; Henriot, V.

1997-05-01

A gas sensor using optical spectrometry and dedicated to a specific gas is studied. It should be able to operate out of laboratories with a very long life and a low maintenance requirement. It is based on TLDS (tunable laser diode spectroscopy) and uses a standard Perot-Fabry laser diode already developed for telecommunications. The mode selection is realized by a passband filter and the wavelength tuning is performed via the diode temperature or its injection current. A PIN photodiode is used for detection, however a rough photoacoustic solution is intended for the future. Absorptions as low as 3.10-3 are detected with this rough system and a limit detection of 10-3 is available with a signal to noise ratio of unity. Experiments have shown that this system is strongly selective for the specified gas (currently the methane). A simulation has been performed which very well fits the experiment and allows us to extrapolate the performances of the system for other gases.

Down to earth in Kyoto?

International Nuclear Information System (INIS)

Gielen, A.; Bollen, J.

1997-01-01

The proposals of the European Union (EU) and the US government for the negotiations at the climatic change conference in Kyoto, Japan, December 1997, are compared. The EU-proposal appears to have more support, but the US-proposal is more effective

A 2004 view of the Kyoto Protocol

International Nuclear Information System (INIS)

Singer, F.

2004-01-01

It may not be a household word, but by now the Kyoto Protocol has become a well-known political slogan. It is either ''fundamentally flawed'' (George W. Bush) or it is essential for saving the climate and humanity (Al Gore). There seems to be no in between. The Kyoto Protocol is a treaty to limit (i.e., ration) the use of energy to satisfy the concerns of environmental groups and other believers in global warming catastrophes. This group includes not only certified kooks but also such notables as former Treasury Secretary Paul O'Neill and Sir David King, chief scientific adviser to Her Majesty's government who equates the threat of warming with that of international terrorism. But Kyoto is quite ineffective, that is, it cannot really affect climate or even change the composition of the atmosphere. It is costly. And it is probably also defunct. Where did this treaty come from? Why is it being adopted by some countries but not by others? And what is its likely future?

Slovenia and Kyoto Obligation

International Nuclear Information System (INIS)

Tirsek, A.; Jevsek, F.; Plavcak, V.-P.

1998-01-01

The paper gives the possibilities of emission reduction as an obligation from Kyoto Protocol. The Slovenia environmental and energy strategies are regulated to implement the agreement to reduce the emissions of greenhouse gases by 8% to the year 2012 as regard the basic year 1986 in energy, transportation, industrial and other sectors, especially focused on electric power sector. (author)

Synchronization scenario of two distant mutually coupled semiconductor lasers

DEFF Research Database (Denmark)

Mulet, Josep; Mirasso, Claudio; Heil, Tilmann

2004-01-01

We present numerical and experimental investigations of the synchronization of the coupling-induced instabilities in two distant mutually coupled semiconductor lasers. In our experiments, two similar Fabry-Perot lasers are coupled via their coherent optical fields. Our theoretical framework is ba...

Amplitude calibration of 2D mechanical resonators by nonlinear optical transduction

NARCIS (Netherlands)

Dolleman, R.J.; Davidovikj, D.; van der Zant, H.S.J.; Steeneken, P.G.

2017-01-01

Contactless characterization of mechanical resonances using Fabry-Perot interferometry is a powerful tool to study the mechanical and dynamical properties of atomically thin membranes. However, amplitude calibration is often not performed or only possible by making assumptions on the device

Determination of the thermospheric neutral wind from incoherent scatter radar measurements

International Nuclear Information System (INIS)

Haeggstroem, I.; Murdin, J.; Rees, D.

1984-11-01

Measurements made by the EISCAT UHF incoherent scatter radar are used to derive thermospheric winds. The derived wind is compared to Fabry-Perot interferometer measurements of the neutral wind made simultaneously. The uncertainties in the radar derived wind are discussed. (author)

The characteristic of the building damage from historical large earthquakes in Kyoto

Science.gov (United States)

Nishiyama, Akihito

2016-04-01

The Kyoto city, which is located in the northern part of Kyoto basin in Japan, has a long history of >1,200 years since the city was initially constructed. The city has been a populated area with many buildings and the center of the politics, economy and culture in Japan for nearly 1,000 years. Some of these buildings are now subscribed as the world's cultural heritage. The Kyoto city has experienced six damaging large earthquakes during the historical period: i.e., in 976, 1185, 1449, 1596, 1662, and 1830. Among these, the last three earthquakes which caused severe damage in Kyoto occurred during the period in which the urban area had expanded. These earthquakes are considered to be inland earthquakes which occurred around the Kyoto basin. The damage distribution in Kyoto from historical large earthquakes is strongly controlled by ground condition and earthquakes resistance of buildings rather than distance from estimated source fault. Therefore, it is necessary to consider not only the strength of ground shaking but also the condition of building such as elapsed years since the construction or last repair in order to more accurately and reliably estimate seismic intensity distribution from historical earthquakes in Kyoto. The obtained seismic intensity map would be helpful for reducing and mitigating disaster from future large earthquakes.

Time of Anderson-Fabry Disease Detection and Cardiovascular Presentation

Directory of Open Access Journals (Sweden)

K. Selthofer-Relatic

2018-01-01

Full Text Available Background. Anderson-Fabry disease is an X-linked inherited disease, which manifests in a different manner depending on gender and genotype. Making a working diagnosis of Anderson-Fabry disease is difficult because of several reasons: (a that it is a multiorgan disease with wide variety of phenotypes, (b different timelines of presentation, (c gender differences, and (d possible coexistence with other comorbidities. Late-onset/cardiac type of presentation with minimal involvement of other organs can additionally make diagnosis difficult. Aim. To describe different cardiac manifestations at different time points in the course of the disease: (1 72-year-old female (echocardiography detection, heterozygote, significant left and mild right ventricular hypertrophy; (2 62-year-old male (echocardiography detection, hemizygote, left ventricular hypertrophy, implanted cardiac pacemaker, a performed percutaneous coronary intervention after myocardial infarction, degenerative medium degree aortic valve stenosis; (3 45-year-old female (asymptomatic/family screening, heterozygote, thickened mitral papillary muscle, mild left ventricular hypertrophy, first degree diastolic dysfunction; and (4 75-year-old female (symptomatic/family screening, heterozygote, cardiomyopathy with reduced left ventricular ejection fraction after heart surgery (mitral valve annuloplasty and plastic repair of the tricuspid valve. Conclusion. All patients have Anderson-Fabry disease but with different clinical presentations depending on the gender, the type of mutation, and the time of detection. All these features can make the patients’ profiles unique and delay the time of detection.

Mutational analysis of the GLA gene in Mexican families with Fabry ...

Indian Academy of Sciences (India)

PRONAF CP 32315, Ciudad Juárez, Chihuahua, México. Abstract. Fabry disease (FD) is a lysosomal storage disorder, which develops due to a deficiency in the hydrolytic enzyme, α-galactosidase A (α-Gal A). Alpha-Gal A hydrolyzes glycosphingolipid globotriaosylceramide (Gb3), and an α-Gal A deficiency leads to Gb3 ...

Cardiac involvement in genotype-positive Fabry disease patients assessed by cardiovascular MR.

Science.gov (United States)

Kozor, Rebecca; Grieve, Stuart M; Tchan, Michel C; Callaghan, Fraser; Hamilton-Craig, Christian; Denaro, Charles; Moon, James C; Figtree, Gemma A

2016-02-15

Cardiac magnetic resonance (CMR) has the potential to provide early detection of cardiac involvement in Fabry disease. We aimed to gain further insight into this by assessing a cohort of Fabry patients using CMR. Fifty genotype-positive Fabry subjects (age 45±2 years; 50% male) referred for CMR and 39 matched controls (age 40±2 years; 59% male) were recruited. Patients had a mean Mainz severity score index of 15±2 (range 0-46), reflecting an overall mild degree of disease severity. Compared with controls, Fabry subjects had a 34% greater left ventricular mass (LVM) index (82±5 vs 61±2 g/m(2), p=0.001) and had a significantly greater papillary muscle contribution to total LVM (13±1 vs 6±0.5%, pgadolinium enhancement (LGE) was present in 15 Fabry subjects (9/21 males and 6/23 females). The most common site for LGE was the basal inferolateral wall (93%, 14/15). There was a positive association between LVM index and LGE. Despite this, there were two males and three females with no LVH that displayed LGE. Of Fabry subjects who were not on enzyme replacement therapy at enrolment (n=28), six were reclassified as having cardiac involvement (four LVH-negative/LGE-positive, one LVH-positive/LGE-positive and one LVH-positive/LGE-negative). CMR was able to detect cardiac involvement in 48% of this Fabry cohort, despite the overall mild disease phenotype of the cohort. Of those not on ERT, 21% were reclassified as having cardiac involvement allowing improved risk stratification and targeting of therapy. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

Fabry disease: Four case reports of meningioma and a review of the literature on other malignancies

Directory of Open Access Journals (Sweden)

Beth L. Thurberg, MD, PhD

2017-06-01

Full Text Available Fabry disease (FD is an X-linked lysosomal storage disorder caused by loss of function mutations in the GLA gene at Xq22 with subsequent functional deficiency of alpha-galactosidase A, resulting in the accumulation of globotriaosylceramide (GL-3 or Gb3 in multiple cells types throughout the body. As with other rare metabolic disorders, little is known about the incidence of malignancies in these populations and the relationship to the underlying disease, if any. We report the occurrence of meningioma in four female patients with Fabry disease. Two of the cases are from the same family and shared the same GLA mutation. All four patients underwent surgical excision of their tumor. High resolution light microscopy and electron microscopy examination of one case revealed extensive involvement of tumor cells and associated blood vessels by GL-3 accumulation. Because of the small number of Fabry-associated cancer cases reported in the literature, questions about a possible link between lysosomal storage disorders and the development of malignancy remain open.

Domo arigato Kyoto: Four key lessons from the Kyoto Protocol for a new agreement in Paris 2015. Climate Brief no. 35

International Nuclear Information System (INIS)

Morel, Romain; Shishlov, Igor; Bellassen, Valentin

2014-05-01

The results from the first commitment period of the Kyoto Protocol (KP) show that developed countries fulfilled their commitments through varied strategies. However, the Kyoto protocol did not manage to stabilize global GHG concentrations; furthermore its direct impact on domestic emissions reductions is unclear. Nevertheless, the KP has likely paved the way for a low-carbon transition by establishing international standards on emissions monitoring and on emission reductions projects. Yet, domestic policies - especially the EU ETS - are the main driver of emissions reductions and the principal catalyzers of private finance flows. A new, more effective, agreement would therefore need to expand its coverage, and take down the specter of 'internationally binding' emission reductions commitments in order to focus on MRV requirements. Similar to Kyoto, a Paris outcome could take the form of a framework agreement setting up requirements and mechanisms with subsequent implementing agreements expected by 2020. (authors)

Prevalence of Fabry Disease and Outcomes in Young Canadian Patients With Cryptogenic Ischemic Cerebrovascular Events.

Science.gov (United States)

Lanthier, Sylvain; Saposnik, Gustavo; Lebovic, Gerald; Pope, Karen; Selchen, Daniel; Moore, David F

2017-07-01

Previous studies reported Fabry disease in 0% to 4% of young patients with cryptogenic ischemic stroke (IS). We sought to determine the prevalence of Fabry and outcomes among young Canadians with cryptogenic IS or transient ischemic attack (TIA). We prospectively enrolled individuals aged 18 to 55 with IS or speech or motor TIA, and no cause identified despite predetermined investigation. α-galactosidase-A gene was sequenced for Fabry diagnosis. National Institutes of Health Stroke Scale score was measured at presentation to quantify stroke severity. Modified Rankin Scale determined functional outcomes ≤7 days after presentation and 6 months later. We enrolled 365 patients with IS and 32 with TIA. α-galactosidase-A sequencing identified a single carrier of a genetic variant of unknown significance (p.R118C) and no well-recognized pathogenic variants. Mean National Institutes of Health Stroke Scale score was 3.1. Proportion of patients with modified Rankin Scale of 0 to 2 was 70.7% at ≤7 days and 87.4% at 6 months. National Institutes of Health Stroke Scale score at presentation and diabetes mellitus predicted 6-month modified Rankin Scale. Thirteen patients experienced 5 recurrent IS and 9 TIA during follow-up. No patient died. Most patients (98.7%) returned home. Among previous workers, 43% had residual working limitations. In this Canadian cohort of patients with cryptogenic IS or TIA, the prevalence of Fabry was 0.3% if p.R118C variant is considered as pathogenic. This suggests that more cost-effective methods should be applied for diagnosis of Fabry rather than systematic genetic screening in this population. Overall, cryptogenic IS in young adults is associated with favorable outcomes. © 2017 American Heart Association, Inc.

Kyotos helte og skurke

DEFF Research Database (Denmark)

Svendsen, Gert Tinggaard

1998-01-01

USA blev på Kyoto-konferencen i december kritiseret af energi- og miljøminister Svend Auken for at ville tjene på et globalt CO2-marked. Men håndhæves dette effektivt af FN, kommer det alle til gode. Et globalt CO2-marked kan blive et banebrydende styringsmiddel, som kan løse globale miljøproblem...

Altered dynamics of a lipid raft associated protein in a kidney model of Fabry disease.

Science.gov (United States)

Labilloy, Anatália; Youker, Robert T; Bruns, Jennifer R; Kukic, Ira; Kiselyov, Kirill; Halfter, Willi; Finegold, David; do Monte, Semiramis Jamil Hadad; Weisz, Ora A

2014-02-01

Accumulation of globotriaosylceramide (Gb3) and other neutral glycosphingolipids with galactosyl residues is the hallmark of Fabry disease, a lysosomal storage disorder caused by deficiency of the enzyme alpha-galactosidase A (α-gal A). These lipids are incorporated into the plasma membrane and intracellular membranes, with a preference for lipid rafts. Disruption of raft mediated cell processes is implicated in the pathogenesis of several human diseases, but little is known about the effects of the accumulation of glycosphingolipids on raft dynamics in the context of Fabry disease. Using siRNA technology, we have generated a polarized renal epithelial cell model of Fabry disease in Madin-Darby canine kidney cells. These cells present increased levels of Gb3 and enlarged lysosomes, and progressively accumulate zebra bodies. The polarized delivery of both raft-associated and raft-independent proteins was unaffected by α-gal A knockdown, suggesting that accumulation of Gb3 does not disrupt biosynthetic trafficking pathways. To assess the effect of α-gal A silencing on lipid raft dynamics, we employed number and brightness (N&B) analysis to measure the oligomeric status and mobility of the model glycosylphosphatidylinositol (GPI)-anchored protein GFP-GPI. We observed a significant increase in the oligomeric size of antibody-induced clusters of GFP-GPI at the plasma membrane of α-gal A silenced cells compared with control cells. Our results suggest that the interaction of GFP-GPI with lipid rafts may be altered in the presence of accumulated Gb3. The implications of our results with respect to the pathogenesis of Fabry disease are discussed. © 2013 Elsevier Inc. All rights reserved.

Kosten en gevolgen bij de toepassing van de Kyoto Mechanismen

NARCIS (Netherlands)

Moor AOG de; Bollen JC; MNV

2001-01-01

Unrestricted use of the Kyoto Mechanisms yields substantial cost savings on the implementation of the Kyoto Protocol. Annex-I emission trading can cut compliance costs by more than a third while global trading can further reduce costs to a fraction of the amount without emission trading. In absolute

Fabry disease mimicking hypertrophic cardiomyopathy: genetic screening needed for establishing the diagnosis in women

DEFF Research Database (Denmark)

Havndrup, Ole; Christiansen, Michael; Stoevring, Birgitte

2010-01-01

AIMS: Fabry disease, an X-linked storage disorder caused by defective lysosomal enzyme alpha-galactosidase A activity, may resemble sarcomere-gene-associated hypertrophic cardiomyopathy (HCM). The 'cardiac variant' of Fabry disease which only affects the heart may be missed unless specifically te...... therapy, supports systematic testing for Fabry disease. Enzyme measurements are sufficient in men, but genetic testing is needed in women....

Light beam control by refractive index change in a modified purple membrane; Hen`i shimaku no kussetsuritsu henka wo riyoshita hikari bimu seigyo

Energy Technology Data Exchange (ETDEWEB)

Takei, H.; Shimizu, N. [Hitachi Ltd., Tokyo (Japan)

1996-04-01

A purple membrane extracted from bacterial halobacterium salinarium is a membrane prepared by two-dimensionally crystallizing bacteriorhodopsin (bR) which is a photo-sensitive protein. When retinal chromophore in the bR absorbs photons, isomerization occurs, so that light cycle of bR comprising a light intermediate of different absorption spectrum occurs. Since this purple membrane has a high stability and a high repetition durability, a study of the application of the same to a rewritable holographic recording medium has been made in recent years. This paper describes an example in which the refractive index variation of a purple membrane the optical characteristics of which varies due to variation is applied to light beam control. The paper introduces a Fabry-Perot resonator as an optical element capable of carrying out light control by utilizing refractive index variation. The paper further describes the possibility of materialization of an optical logic comprising a combination of light-irradiation refractive index variation and a Fabry-Perot resonator and having nonlinear input/output characteristics such as the bistablity owing to the feedback effect in the resonator. 7 refs., 3 figs.

A fiber-optic strain measurement and quench localization system for use in superconducting accelerator dipole magnets

NARCIS (Netherlands)

van Oort, J.M.; Scanlan, Ronald M.; ten Kate, Herman H.J.

1995-01-01

A novel fiber-optic measurement system for superconducting accelerator magnets is described. The principal component is an extrinsic Fabry-Perot interferometer to determine localized strain and stress in coil windings. The system can be used either as a sensitive relative strain measurement system

Electron Interference in Ballistic Graphene Nanoconstrictions

DEFF Research Database (Denmark)

Baringhaus, Jens; Settnes, Mikkel; Aprojanz, Johannes

2016-01-01

We realize nanometer size constrictions in ballistic graphene nanoribbons grown on sidewalls of SiC mesa structures. The high quality of our devices allows the observation of a number of electronic quantum interference phenomena. The transmissions of Fabry-Perot-like resonances are probed...

LSPR and Interferometric Sensor Modalities Combined Using a Double-Clad Optical Fiber.

Science.gov (United States)

Muri, Harald Ian; Bano, Andon; Hjelme, Dag Roar

2018-01-11

We report on characterization of an optical fiber-based multi-parameter sensor concept combining localized surface plasmon resonance (LSPR) signal and interferometric sensing using a double-clad optical fiber. The sensor consists of a micro-Fabry-Perot in the form of a hemispherical stimuli-responsive hydrogel with immobilized gold nanorods on the facet of a cleaved double-clad optical fiber. The swelling degree of the hydrogel is measured interferometrically using the single-mode inner core, while the LSPR signal is measured using the multi-mode inner cladding. The quality of the interferometric signal is comparable to previous work on hydrogel micro-Fabry-Perot sensors despite having gold nanorods immobilized in the hydrogel. We characterize the effect of hydrogel swelling and variation of bulk solution refractive index on the LSPR peak wavelength. The results show that pH-induced hydrogel swelling causes only weak redshifts of the longitudinal LSPR mode, while increased bulk refractive index using glycerol and sucrose causes large blueshifts. The redshifts are likely due to reduced plasmon coupling of the side-by-side configuration as the interparticle distance increases with increasing swelling. The blueshifts with increasing bulk refractive index are likely due to alteration of the surface electronic structure of the gold nanorods donated by the anionic polymer network and glycerol or sucrose solutions. The recombination of biotin-streptavidin on gold nanorods in hydrogel showed a 7.6 nm redshift of the longitudinal LSPR. The LSPR response of biotin-streptavidin recombination is due to the change in local refractive index (RI), which is possible to discriminate from the LSPR response due to changes in bulk RI. In spite of the large LSPR shifts due to bulk refractive index, we show, using biotin-functionalized gold nanorods binding to streptavidin, that LSPR signal from gold nanorods embedded in the anionic hydrogel can be used for label-free biosensing. These

LSPR and Interferometric Sensor Modalities Combined Using a Double-Clad Optical Fiber

Directory of Open Access Journals (Sweden)

Harald Ian Muri

2018-01-01

Full Text Available We report on characterization of an optical fiber-based multi-parameter sensor concept combining localized surface plasmon resonance (LSPR signal and interferometric sensing using a double-clad optical fiber. The sensor consists of a micro-Fabry-Perot in the form of a hemispherical stimuli-responsive hydrogel with immobilized gold nanorods on the facet of a cleaved double-clad optical fiber. The swelling degree of the hydrogel is measured interferometrically using the single-mode inner core, while the LSPR signal is measured using the multi-mode inner cladding. The quality of the interferometric signal is comparable to previous work on hydrogel micro-Fabry-Perot sensors despite having gold nanorods immobilized in the hydrogel. We characterize the effect of hydrogel swelling and variation of bulk solution refractive index on the LSPR peak wavelength. The results show that pH-induced hydrogel swelling causes only weak redshifts of the longitudinal LSPR mode, while increased bulk refractive index using glycerol and sucrose causes large blueshifts. The redshifts are likely due to reduced plasmon coupling of the side-by-side configuration as the interparticle distance increases with increasing swelling. The blueshifts with increasing bulk refractive index are likely due to alteration of the surface electronic structure of the gold nanorods donated by the anionic polymer network and glycerol or sucrose solutions. The recombination of biotin-streptavidin on gold nanorods in hydrogel showed a 7.6 nm redshift of the longitudinal LSPR. The LSPR response of biotin-streptavidin recombination is due to the change in local refractive index (RI, which is possible to discriminate from the LSPR response due to changes in bulk RI. In spite of the large LSPR shifts due to bulk refractive index, we show, using biotin-functionalized gold nanorods binding to streptavidin, that LSPR signal from gold nanorods embedded in the anionic hydrogel can be used for label

The Kyoto meeting has given a clear signal. The 3rd conference of signatory states to the UN Framework Convention on Climate Change: Current situation, negotiation dynamics, results; Kyoto-Gipfel hat deutliches Signal gesetzt. Die 3. VSK zur KRK: Ausgangslage, Verhandlungsdynamik, Ergebnis

Energy Technology Data Exchange (ETDEWEB)

Lamprecht, F.

1998-01-01

This third meeting of the Parties to the UN Framework Convention on Climate Change, held from 1-10 December 1997 in Kyoto/Japan, on which high expectations had been placed, just as on the Berlin meeting two years ago, has certainly not come up to expectations, but still agreed upon a Protocol that can be called an important signpost in international policy for protection of the environment. The envisaged greenhouse gas reduction by 5.2 per cent (of 1990 emissions) laid down in the Protocol, to be achieved by the industrialized countries either individually or by Joint Implementation over the period from 2008 until 2012, is a positive result considering the present situation. Although the agreed cutback falls short of the figures given by climate experts (who demand at least a 20% reduction by the year 2005), the obligation of the USA, the worldwide biggest emitter of greenhouse gases, to achieve a mandatory minimum cutback in emissions of 7% can be considered a big success. (orig./CB) [Deutsch] Auf der wie vor zwei Jahren in Berlin mit stark ueberzogenen Erwartungen ueberfrachteten 3. Vertragsstaatenkonferenz (VSK) zur Klimarahmenkonvention (KRK) vom 1.-10. Dezember 1997 in Kyoto/Japan ist ein zwar bescheidender, aber wichtiger Meilenstein der internationalen Umweltpoltik gesetzt worden. Die im Kyoto-Protokoll festgeschriebene, von den Industrielaendern individuell oder gemeinsam in der Periode 2008-2012 im Durchschnitt zu erzielende Treibhausgasreduktion von insgesamt 5,2% (Basis 1990) ist, gemessen an der Ausgangslage, positiv zu werten. Wenngleich damit die Forderung der Klimaforscher (mindestens 20%-Reduktion bis 2005) nicht erreicht wurde, muss die 7%-Minderungsverpflichtung des weltgroessten Treibhausgasemittenten USA als grosser Erfolg gesehen werden. (orig./RHM)

Energy utilization of induced pluripotent stem cell-derived cardiomyocyte in Fabry disease.

Science.gov (United States)

Chou, Shih-Jie; Yu, Wen-Chung; Chang, Yuh-Lih; Chen, Wen-Yeh; Chang, Wei-Chao; Chien, Yueh; Yen, Jiin-Cherng; Liu, Yung-Yang; Chen, Shih-Jen; Wang, Chien-Ying; Chen, Yu-Han; Niu, Dau-Ming; Lin, Shing-Jong; Chen, Jaw-Wen; Chiou, Shih-Hwa; Leu, Hsin-Bang

2017-04-01

Fabry disease (FD) is a lysosomal storage disease in which glycosphingolipids (GB3) accumulate in organs of the human body, leading to idiopathic hypertrophic cardiomyopathy and target organ damage. Its pathophysiology is still poorly understood. We aimed to generate patient-specific induced pluripotent stem cells (iPSC) from FD patients presenting cardiomyopathy to determine whether the model could recapitulate key features of the disease phenotype and to investigate the energy metabolism in Fabry disease. Peripheral blood mononuclear cells from a 30-year-old Chinese man with a diagnosis of Fabry disease, GLA gene (IVS4+919G>A) mutation were reprogrammed into iPSCs and differentiated into iPSC-CMs and energy metabolism was analyzed in iPSC-CMs. The FD-iPSC-CMs recapitulated numerous aspects of the FD phenotype including reduced GLA activity, cellular hypertrophy, GB3 accumulation and impaired contractility. Decreased energy metabolism with energy utilization shift to glycolysis was observed, but the decreased energy metabolism was not modified by enzyme rescue replacement (ERT) in FD-iPSCs-CMs. This model provided a promising in vitro model for the investigation of the underlying disease mechanism and development of novel therapeutic strategies for FD. This potential remedy for enhancing the energetic network and utility efficiency warrants further study to identify novel therapies for the disease. Copyright © 2017 Elsevier B.V. All rights reserved.

Anomalous broadening of the N2+ first negative band system

International Nuclear Information System (INIS)

Robben, F.; Cattolica, R.; Coe, D.; Talbot, L.

1976-01-01

Analysis of the fluorescence excited by a high energy electron beam has become a standard technique for measurement of density, rotational temperature of nitrogen, and translational temperature of helium and argon in rarefied gas dynamics. To obtain translational temperature the Doppler broadening of the fluorescence is determined by measuring the spectral line shape with a Fabry-Perot interferometer. To apply this technique to nitrogen a single rotational line must be selected from the band spectrum for analysis by the Fabry-Perot interferometer. As supported by extensive additional measurements, there is an anomalous broadening of the rotational lines of the N 2 + first negative band system with a width equivalent to about a 70 0 K translational temperature of nitrogen. It appears that the line width of approximately 0.03 cm -1 is an inherent property of this nitrogen band when excited by electron impact directly from the ground state

Fiber optic hydrophone

Science.gov (United States)

Kuzmenko, Paul J.; Davis, Donald T.

1994-01-01

A miniature fiber optic hydrophone based on the principles of a Fabry-Perot interferometer. The hydrophone, in one embodiment, includes a body having a shaped flexible bladder at one end which defines a volume containing air or suitable gas, and including a membrane disposed adjacent a vent. An optic fiber extends into the body with one end terminating in spaced relation to the membrane. Acoustic waves in the water that impinge on the bladder cause the pressure of the volume therein to vary causing the membrane to deflect and modulate the reflectivity of the Fabry-Perot cavity formed by the membrane surface and the cleaved end of the optical fiber disposed adjacent to the membrane. When the light is transmitted down the optical fiber, the reflected signal is amplitude modulated by the incident acoustic wave. Another embodiment utilizes a fluid filled volume within which the fiber optic extends.

Córnea verticilata - marcador clínico da doença de Fabry: relato de caso Cornea verticillata - a clinical marker of Fabry disease: case report

Directory of Open Access Journals (Sweden)

Cynthia Azeredo Cordeiro

2007-08-01

Full Text Available A doença de Fabry é erro inato do metabolismo dos glicoesfingolipídeos (GL, resultante da atividade deficiente da enzima alfa-galactosidase A (a-Gal, com herança ligada ao cromossomo X. O acúmulo progressivo de GL nos tecidos resulta nas manifestações clínicas da doença, mais evidentes em homens hemizigotos, e incluem angioqueratomas, acroparestesias, córnea verticilata, hipo-hidrose, envolvimento cardíaco, renal e manifestações cerebrovasculares. Foi realizada avaliação em família acometida pela doença, sendo dois pacientes do sexo feminino e três do sexo masculino. Todos os pacientes foram submetidos a anamnese, exame oftalmológico completo e dosagem da atividade da enzima a-Gal. O único achado clínico presente em todos foi a córnea verticilata. Isto demonstra o importante papel que o exame oftalmológico apresenta no diagnóstico da doença, já que as alterações oculares são tão características.Fabry's disease is a rare X-linked lisosomal storage disorder of glycosphingolipid (GL metabolism, caused by a deficiency of alpha-galactosidase A activity. The progressive accumulation of GL in tissues results in the clinical manifestations of the disease, that are more evident in hemizygous males, and include angiokeratomas, acroparesthesia, cornea verticillata, cardiac and kidney involvement, cerebrovascular manifestations. A family with Fabry's disease including 2 female patients and 3 male patients is reported. The patients were submitted to complete medical history, ophthalmological examination and alpha-galactosidase activity test. Cornea verticillata was a constant finding in all patients. This demonstrates the important role of the ophtalmological examination for the diagnosis of Fabry's disease since the eye findings are so characteristic of the disease.

The Project Based Mechanisms of the Kyoto Protocol. Credible Instruments or Challenges to the Integrity of the Kyoto Protocol?

Energy Technology Data Exchange (ETDEWEB)

Takeuchi Waldegren, Linn

2006-03-15

The project based mechanisms of the Kyoto Protocol are innovative instruments which allow projects to earn credits for reducing greenhouse gas (GHG) emissions. The credits can in turn be used by countries to reach their emissions targets according to the Kyoto Protocol. The Project based mechanisms are known as the Clean Development Mechanism (CDM) and the Joint Implementation (JI). If the project based mechanisms are to be effective policy instruments they must ensure the integrity of the Kyoto Protocol, and their ability to promote and prove real emission reductions is critical. The environmental credibility of the project based mechanisms will also ensure their ability to promote cost effectiveness. Key concepts in this context are environmental and project additionality, and their role and value for the project based mechanisms are analyzed. Environmental additionality is established by comparing a project's emissions to a baseline. The baseline's credibility is thus vital. The concept of project additionality is somewhat controversial, but is nonetheless of equal importance. The case studies of CDM approved methodologies (AMs) and proposed projects suggest that there are credibility issues that need to be addressed if the project based mechanisms are to promote real emissions reductions.

Photodetachment spectroscopy and microscopy; measurement of the photodetachment cross section of H- at 1064 nm by the observation of the asymptotic behaviour in the saturated regime

International Nuclear Information System (INIS)

Vandevraye, Mickael

2013-01-01

In this thesis, we initiate the demonstration, at a reduced scale, of the feasibility of the almost-complete laser photodetachment of negative hydrogen ion beams in a Fabry-Perot optical cavity for future neutral beam injectors for the heating of fusion power plants plasmas.We develop a new method to measure a photodetachment cross section, the knowledge of which at the exciting wavelength is needed to scale the Fabry-Perot cavity, based on the observation of the saturation in a pulsed lighting regime. The analytical calculus of the detachment signal growth produced while illuminating a negative ion beam with a Gaussian laser pulse bring out a mathematical constraint on the required flux to pass through the saturated regime. This constraint is the signature of the transition toward the saturation for all experiment carried out in Gaussian beam and for all linear light-matter interaction processes. With this method, we measure the photodetachment cross section of H - at 1064 nm - selected wavelength for future neutral beam injectors - in slight disagreement with theoretical predictions.To reduce the technological requirement on the Fabry-Perot cavity and the laser, we study Landau resonances which appear in the photodetachment spectrum. Locking the laser on one of these resonances would allow increasing the photodetachment probability at a given flux.We also present our phosphorus, selenium and tin electron affinity measurements carried out with the photodetachment microscope. The photodetachment microscopy experiment of phosphorus is the first one where the neutral atom is left in an excited term. (author) [fr

The costs and benefits of early action before Kyoto compliance

International Nuclear Information System (INIS)

Pan, Haoran; Regemorter, D. van

2004-01-01

Transaction costs have negative effects on emissions trading. Recent debates on the Kyoto Protocol have emphasized the potential threat of transaction costs to the implementation of emissions trading for the Protocol and consequently to the successful implementation of the Protocol. One way to suppress transaction costs is to use experience. In line with the EU Green Paper, we propose that an experimental early action before the Kyoto period could be helpful to reduce the transaction costs in emissions trading for the Kyoto compliance. However, because early action will incur additional costs, the final gain due to early action will be the cost-saving net of the costs of early action. This paper explores the relationship between the transaction costs in emissions trading and the early action effort to reduce transaction costs in the case of Kyoto Protocol. We find that in general early action can effectively offset transaction costs and thus are economically efficient. Only in the case of high transaction costs and constantly slow learning process, early action may become inefficient

The nature of the high-velocity gas in NGC 1275: first results with TAURUS-2 on the William Herschel telescope

International Nuclear Information System (INIS)

Unger, S.W.; Taylor, K.; Pedlar, A.; Ghataure, H.S.; Penston, M.V.; Robinson, A.

1990-01-01

Observations with a new imaging Fabry-Perot interferometer, TAURUS-2, show that there is a close spatial association between the two systems of emission-line gas in the active galaxy NGC 1275 (Perseus A, 3C84). It therefore seems likely that, as first suggested by previous authors, we are witnessing two galaxies in the process of colliding. We show that this hypothesis is consistent with all available observations of this object. (author)

Making it work: Kyoto, trade and politics : Executive summary

Energy Technology Data Exchange (ETDEWEB)

Urquhar, I.

2002-11-01

In this document, the author examines the constraints that would be placed on policy makers in the event of the implementation of the Kyoto Protocol, and how it would affect trade agreements and federalism in Canada. A description of the Protocol and the concessions (carbon sinks and international emissions trading) gained by Canada are presented at the beginning of the document. The author offers several conclusions that could disturb both proponents and opponents of the Kyoto Protocol. It is said that the implementation of Kyoto can take a route other than that of drastic domestic emissions reductions, and this position is explored in the second section. The author indicates that corporate competitiveness could be boosted by strict environmental regulations. A range of policies that could be adopted by Canada, as proposed by numerous organizations, are highlighted in the third section of the document. The point of the World Trade Organization and the constraints imposed are not necessarily preventing all types of actions. However, the author is of the opinion that the North America Free Trade Agreement represents a real threat to the implementation of the Kyoto Protocol. Finally, it is indicated that Canada requires a national electricity policy, where big hydro utilities and public investment have major roles to play.

Vortex-MEMS filters for wavelength-selective orbital-angular-momentum beam generation

DEFF Research Database (Denmark)

Paul, Sujoy; Lyubopytov, Vladimir; Schumann, Martin F.

2017-01-01

In this paper an on-chip device capable of wavelength-selective generation of vortex beams is demonstrated. The device is realized by integrating a spiral phase-plate onto a MEMS tunable Fabry-Perot filter. This vortex-MEMS filter, being capable of functioning simultaneously in wavelength...

Effect of optical waveguiding mechanism on the lasing action of chirped InAs/AlGaInAs/InP quantum dash lasers

KAUST Repository

Khan, Mohammed Zahed Mustafa; Ng, Tien Khee; Lee, C.-S.; Bhattacharya, P.; Ooi, Boon S.

2013-01-01

We report on the atypical emission dynamics of InAs/AlGaInAs/InP quantum dash (Qdash) lasers employing varying AlGaInAs barrier thickness (multilayer-chirped structure). The analysis is carried out via fabry-perot (FP) ridge (RW) and stripe

Precise length etalon controlled by stabilized frequency comb

Czech Academy of Sciences Publication Activity Database

Šmíd, Radek; Číp, Ondřej; Lazar, Josef

2008-01-01

Roč. 8, č. 5 (2008), Section 3: 114-117 ISSN 1335-8871 R&D Projects: GA AV ČR IAA200650504; GA MŠk(CZ) LC06007; GA MŠk 2C06012; GA AV ČR KAN311610701; GA MPO 2A-1TP1/127; GA MPO FT-TA3/133; GA ČR GA102/07/1179 Institutional research plan: CEZ:AV0Z20650511 Keywords : Fabry-Perot * interferometer * femtosecond * etalon Subject RIV: BH - Optics, Masers, Lasers

Cochleovestibular Manifestations in Fabry Disease

Directory of Open Access Journals (Sweden)

Alberto Ciceran MD

2016-09-01

Full Text Available Fabry disease is a rare, X-linked lysosomal storage disorder resulting from deficient α-galactosidase A activity and globotriaosylceramide accumulation throughout the body. This accumulation leads to various clinical disorders, including inner ear lesions, with sensorineural hearing loss and dizziness. Although hearing loss is recognized in these patients, its incidence and natural history have not been characterized. Hearing disorders develop mainly in adulthood, and tinnitus may be an earlier symptom in Fabry disease. A significant incidence of mid- and high-frequency sensorineural hearing loss in affected males is commonly reported, whereas in female carriers, it is much less frequent. In addition, a high incidence of vestibular disorders with dizziness and chronic instability is also observed in these patients. The few studies about the effects of enzyme replacement therapy (ERT on cochleovestibular symptoms show controversial results. Based on the model of densely stained material accumulation in the inner ear, stria vascularis cell, and organ damage, an early indication of ERT may prevent hearing loss due to the reduction in substrate accumulation.

The Kyoto conference: French perspective

International Nuclear Information System (INIS)

Orliange Philippe

1998-02-01

The present article approaches the problem of the climate change from a French perspective, describing the process that let the topic acquire importance in the national government level. Also, they stand out the difficulties generated in the negotiations of the Kyoto Protocol, because the opposing positions have United States and the European block

The Kyoto Protocol Is Cost-effective

Directory of Open Access Journals (Sweden)

Marino Gatto

2002-06-01

Full Text Available Despite recent advances, there is a high degree of uncertainty concerning the climate change that would result from increasing atmospheric greenhouse gas concentrations. Also, opponents of the Kyoto Protocol raised the key objection that reducing emissions would impose an unacceptable economic burden on businesses and consumers. Based on an analysis of alternative scenarios for electricity generation in Italy, we show that if the costs in terms of damage to human health, material goods, agriculture, and the environment caused by greenhouse gas emissions are included in the balance, the economic argument against Kyoto is untenable. Most importantly, the argument holds true even if we exclude global external costs (those due to global warming, and account for local external costs only (such as those due to acidic precipitation and lung diseases resulting from air pollution.

SPIRAL STRUCTURE OF M51 - DISTRIBUTION AND KINEMATICS OF THE ATOMIC AND IONIZED HYDROGEN

NARCIS (Netherlands)

TILANUS, RPJ; ALLEN, RJ

The atomic hydrogen (H I) and the H-alpha emission lines in the grand-design spiral galaxy M51 have been observed with the Westerbork Synthesis Radio Telescope and the TAURUS Fabry-Perot imaging spectrometer, respectively. Across the inner spiral arms significant tangential and radial velocity

The Prevalence of Fabry Disease in Patients with Chronic Kidney Disease in Turkey: The TURKFAB Study

Directory of Open Access Journals (Sweden)

Kultigin Turkmen

2016-12-01

Full Text Available Background/Aims: Fabry disease is a treatable cause of chronic kidney disease (CKD characterized by a genetic deficiency of α-galactosidase A. European Renal Best Practice (ERBP recommends screening for Fabry disease in CKD patients. However, this is based on expert opinion and there are no reports of the prevalence of Fabry disease in stage 1-5 CKD. Hence, we investigated the prevalence of Fabry disease in CKD patients not receiving renal replacement therapy. Methods: This prospective study assessed α-galactosidase activity in dried blood spots in 313 stage 1-5 CKD patients, 167 males, between ages of 18-70 years whose etiology of CKD was unknown and were not receiving renal replacement therapy. The diagnosis was confirmed by GLA gene mutation analysis. Results: Three (all males of 313 CKD patients (0.95% were diagnosed of Fabry disease, for a prevalence in males of 1.80%. Family screening identified 8 aditional Fabry patients with CKD. Of a total of 11 Fabry patients, 7 were male and started enzyme replacement therapy and 4 were female. The most frequent manifestations in male patients were fatigue (100%, tinnitus, vertigo, acroparesthesia, hypohidrosis, cornea verticillata and angiokeratoma (all 85%, heat intolerance (71%, and abdominal pain (57%. The most frequent manifestations in female patients were fatigue and cornea verticillata (50%, and tinnitus, vertigo and angiokeratoma (25%. Three patients had severe episodic abdominal pain attacks and proteinuria, and were misdiagnosed as familial Mediterranean fever. Conclusions: The prevalence of Fabry disease in selected CKD patients is in the range found among renal replacement therapy patients, but the disease is diagnosed at an earlier, treatable stage. These data support the ERBP recommendation to screen for Fabry disease in patients with CKD of unknown origin.

Solar Cycle Variation of Upper Thermospheric Temperature Over King Sejong Station, Antarctica

Science.gov (United States)

Chung, Jong-Kyun; Won, Young-In; Kim, Yong-Ha; Lee, Bang-Yong; Kim, Jhoon

2000-12-01

A ground Fabry-Perot interferometer has been used to measure atomic oxygen nightglow (OI 630.0 nm) from the thermosphere (about 250 km) at King Sejong station (KSS, geographic: 62.22oS, 301.25oE; geomagnetic: 50.65oS, 7.51oE), Antarctica. While numerous studies of the thermosphere have been performed on high latitude using ground-based Fabry-Perot interferometers, the thermospheric measurements in the Southern Hemisphere are relatively new and sparse. Therefore, the nightglow measurements at KSS play an important role in extending the thermospheric studies to the Southern Hemisphere. In this study, we investigated the effects of the geomagnetic and solar activities on the thermospheric neutral temperatures that have been observed at KSS in 1989 and 1997. The measured average temperatures are 1400 K in 1989 and 800 K in 1997, reflecting the influence of the solar activity. The measurements were compared with empirical models, MSIS-86 and semi-empirical model, VSH.

Solar Cycle Variation of Upper Thermospheric Temperature Over King Sejong Station, Antarctica

Directory of Open Access Journals (Sweden)

Jong-Kyun Chung

2000-12-01

Full Text Available A ground Fabry-Perot interferometer has been used to measure atomic oxygen nightglow (OI 630.0 nm from the thermosphere (about 250 km at King Sejong station (KSS, geographic: 62.22oS, 301.25oE; geomagnetic: 50.65oS, 7.51oE, Antarctica. While numerous studies of the thermosphere have been performed on high latitude using ground-based Fabry-Perot interferometers, the thermospheric measurements in the Southern Hemisphere are relatively new and sparse. Therefore, the nightglow measurements at KSS play an important role in extending the thermospheric studies to the Southern Hemisphere. In this study, we investigated the effects of the geomagnetic and solar activities on the thermospheric neutral temperatures that have been observed at KSS in 1989 and 1997. The measured average temperatures are 1400 K in 1989 and 800 K in 1997, reflecting the influence of the solar activity. The measurements were compared with empirical models, MSIS-86 and semi-empirical model, VSH.

Fiber-linked interferometric pressure sensor

Science.gov (United States)

Beheim, G.; Fritsch, K.; Poorman, R. N.

1987-01-01

A fiber-optic pressure sensor is described which uses a diaphragm to modulate the mirror separation of a Fabry-Perot cavity (the sensing cavity). A multimode optical fiber delivers broadband light to the sensing cavity and returns the spectrally modulated light which the cavity reflects. The sensor's output spectrum is analyzed using a tunable Fabry-Perot cavity (the reference cavity) to determine the mismatch in the mirror separations of the two cavities. An electronic servo control uses this result to cause the mirror separation of the reference cavity to equal that of the sensing cavity. The displacement of the pressure-sensing diaphragm is then obtained by measuring the capacitance of the reference cavity's metal-coated mirrors. Relative to other fiber-optic sensors, an important advantage of this instrument is its high immunity to the effects of variations in both the transmissivity of the fiber link and the wavelength of the optical source.

Tunable Fano Resonance in Asymmetric MIM Waveguide Structure.

Science.gov (United States)

Zhao, Xuefeng; Zhang, Zhidong; Yan, Shubin

2017-06-25

A plasmonic waveguide coupled system that uses a metal-insulator-metal (MIM) waveguide with two silver baffles and a coupled ring cavity is proposed in this study. The transmission properties of the plasmonic system were investigated using the finite element method. The simulation results show a Fano profile in the transmission spectrum, which was caused by the interaction of the broadband resonance of the Fabry-Perot (F-P) cavity and the narrow band resonance of the ring cavity. The Fabry-Perot (F-P) cavity in this case was formed by two silver baffles dividing the MIM waveguide. The maximum sensitivity of 718 nm/RIU and the maximum figure of merit of 4354 were achieved. Furthermore, the effects of the structural parameters of the F-P cavity and the ring cavity on the transmission properties of the plasmonic system were analyzed. The results can provide a guide for designing highly sensitive on-chip sensors based on surface plasmon polaritons.

Dual-wavelength passive and hybrid mode-locking of 3, 4.5 and 10 GHz InAs/InP(100) quantum dot lasers.

Science.gov (United States)

Tahvili, M S; Du, L; Heck, M J R; Nötzel, R; Smit, M K; Bente, E A J M

2012-03-26

We present an investigation of passive and hybrid mode-locking in Fabry-Pérot type two-section InAs/InP(100) quantum dot lasers that show dual wavelength operation. Over the whole current and voltage range for mode-locking of these lasers, the optical output spectra show two distinct lobes. The two lobes provide a coherent bandwidth and are verified to lead to two synchronized optical pulses. The generated optical pulses are elongated in time due to a chirp which shows opposite signs over the two spectral lobes. Self-induced mode-locking in the single-section laser shows that the dual-wavelength spectra correspond to emission from ground state. In the hybrid mode-locking regime, a map of locking range is presented by measuring the values of timing jitter for several values of power and frequency of the external electrical modulating signal. An overview of the systematic behavior of InAs/InP(100) quantum dot mode-locked lasers is presented as conclusion.

A Kinematic Link Between Boxy Bulges, Stellar Bars, and Nuclear Activity in NGC 3079 and NGC 4388

Science.gov (United States)

Veilleux, S.; Bland-Hawthrorn, J.; Cecil, Gerald

1999-01-01

We present direct kinematic evidence for bar streaming in two active galaxies with boxy stellar bulges. The Hawaii Imaging Fabry-Perot Interferometer was used on the Canada-France-Hawaii 3.6-m telescope and the University of Hawaii 2.2-m telescope to derive the two-dimensional velocity field of the line-emitting gas in the disks of the Sc galaxy NGC 3079 and the Sb galaxy NGC 4388. In contrast to previous work based on long-slit data, the detection of the bar potential from the Fabry-Perot data does not rely on the existence of inner Lindblad resonances or strong bar-induced shocks. Simple kinematic models which approximate the intrinsic gas orbits as nonintersecting, inclined elliptical annuli that conserve angular momentum characterize the observed velocity fields. In NGC 3079, bar streaming motions with moderately eccentric orbits (e = b/a approx. 0.7) aligned along PA = 130 deg. intrinsic to the disk (PA = 97 deg. on the sky) are detected out to R(sub b) = 3.6 kpc. The orbits become increasingly circular beyond that radius (e = 1 at R(sub d) approx. = 6 kpc). The best model for NGC 4388 includes highly eccentric orbits (e approx. 0.3) for R(sub) less than or equal to 1.5 kpc which are aligned along PA = 135 deg. intrinsic to the disk (PA = 100 deg. on the sky). The observed "spiral arms" are produced by having the orbits become increasingly circular from the ends of the bar to the edge of the disk (R(sub d) approx. = 5 kpc), and the intrinsic bar PA shifting from 135 deg. to 90 deg.. Box-shaped bulges in both NGC 3079 and NGC 4388 are confirmed using new near-infrared images to reduce dust obscuration. Morphological analysis of starlight in these galaxies is combined with the gas kinematics derived from the Fabry-Perot spectra to test evolutionary models of stellar bars that involve transitory boxy bulges, and to quantify the importance of such bars in fueling active nuclei. Our data support the evolutionary bar models, but fail to prove convincingly that the

Pain in Fabry Disease: Practical Recommendations for Diagnosis and Treatment.

Science.gov (United States)

Politei, Juan M; Bouhassira, Didier; Germain, Dominique P; Goizet, Cyril; Guerrero-Sola, Antonio; Hilz, Max J; Hutton, Elspeth J; Karaa, Amel; Liguori, Rocco; Üçeyler, Nurcan; Zeltzer, Lonnie K; Burlina, Alessandro

2016-07-01

Patients with Fabry disease (FD) characteristically develop peripheral neuropathy at an early age, with pain being a crucial symptom of underlying pathology. However, the diagnosis of pain is challenging due to the heterogeneous and nonspecific symptoms. Practical guidance on the diagnosis and management of pain in FD is needed. In 2014, experts met to discuss recent advances on this topic and update clinical guidance. Emerging disease-specific tools, including FabryScan, Fabry-specific Pediatric Health and Pain Questionnaire, and Würzburg Fabry Pain Questionnaire, and more general tools like the Total Symptom Score can aid diagnosis, characterization, and monitoring of pain in patients with FD. These tools can be complemented by more objective and quantifiable sensory testing. In male and female patients of any age, pain related to FD can be an early indication to start disease-specific enzyme replacement therapy before potentially irreversible organ damage to the kidneys, heart, or brain occurs. To improve treatment outcomes, pain should be diagnosed early in unrecognized or newly identified FD patients. Treatment should include: (a) enzyme replacement therapy controlling the progression of underlying pathology; (b) adjunctive, symptomatic pain management with analgesics for chronic neuropathic and acute nociceptive, and inflammatory or mixed pain; and (c) lifestyle modifications. © 2016 The Authors. CNS Neuroscience & Therapeutics published by John Wiley & Sons Ltd.

Lipid profile in adult patients with Fabry disease - Ten-year follow up

Directory of Open Access Journals (Sweden)

Karolina M. Stepien

2017-12-01

Conclusion: Adult patients with Fabry disease have remarkably elevated HDL-cholesterol and as a result, elevated total cholesterol. It is possible that elevated HDL-cholesterol has a cardioprotective effect in patients with this condition. Long term ERT does not have a significant impact on lipid profile in female and male population with Fabry disease.

Kyoto protocol and Nepal's energy sector

International Nuclear Information System (INIS)

Pokharel, Shaligram

2007-01-01

Nepal has recently ratified Kyoto Protocol, which considers justifiable use of resources to limit or reduce the emission of gases that contribute to green house gas inventory in the atmosphere. Nepal's per capita green gas (GHG) emission from energy use is insignificant. However, it is important for Nepal to adopt environmentally friendly energy options based on local resources like hydropower and biomass. Nepal can benefit from the provisions of clean development mechanism (CDM) under the Kyoto Protocol of the United Nations Framework Convention on Climate Change (UNFCC) or carbon funds being promoted by various organizations in order to obtain funding for new projects that reduce GHG emissions (ER). Funding can be generated through Carbon trading in international market as well. In this paper, the country's current contribution to GHG due to energy consumption is evaluated. Options for promoting more sustainable and environmentally friendly projects have also been discussed

Influence of outdoor advertisement colors on psychological evaluation of townscape in Kyoto

Science.gov (United States)

Onishi, Ayumi; Ishida, Taiichiro; Katsuya, Yoshiko

2002-06-01

Outdoor advertisements must be one of the major factors that affect our psychological impression for townscapes. They often conflict with propr color environments in cities particularly in historic cities like Kyoto. In this study we investigated how outdoor advertisements influenced our visual evaluation of townscapes in Kyoto. In recent years, a new regulation for outdoor advertisements came into operation in Kyoto and some of the advertisements have been replaced or removed gradually. We examined psychological evaluation for the townscapes before and after their changes. In the experiment, subjects evaluated 'visual harmony,' 'visual busyness,' 'visual comfort' and 'suitability to Kyoto' of townscapes projected on a screen. The results indicated that the evaluation of 'visual busyness' significantly decreased with the amount of the advertisements. The relations between the advertisements and the psychological evaluation of the townscape are discussed.

The Kyoto mechanisms and the diffusion of renewable energy technologies in the BRICS

International Nuclear Information System (INIS)

Bodas Freitas, Isabel Maria; Dantas, Eva; Iizuka, Michiko

2012-01-01

This paper examines whether the Kyoto mechanisms have stimulated the diffusion of renewable energy technologies in the BRICS, i.e. Brazil, Russian, India China and South Africa. We examine the patterns of diffusion of renewable energy technologies in the BRICS, the factors associated with their diffusion, and the incentives provided by the Kyoto mechanisms. Preliminary analysis suggests that the Kyoto mechanisms may be supporting the spread of existing technologies, regardless if such technologies are still closely tied to environmental un-sustainability, rather than the development and diffusion of more sustainable variants of renewable energy technologies. This raises questions about the incentives provided by the Kyoto mechanisms for the diffusion of cleaner variants of renewable energy technologies in the absence of indigenous technological efforts and capabilities in sustainable variants, and national policy initiatives to attract and build on Kyoto mechanism projects. We provide an empirical analysis using aggregated national data from the World Development Indicators, the International Energy Agency, the United Nations Framework Convention on Climate Change and secondary sources. - Highlights: ► The Kyoto mechanisms may be supporting the diffusion of existing technologies. ► They may not be supporting the diffusion of sustainable renewable energy technologies. ► In the absence of appropriate capabilities and policies further diffusion is limited.

Application of the Kyoto Mechanisms in Finland's climate policy. Report of the Finnish Committee on the Kyoto mechanisms

International Nuclear Information System (INIS)

2001-01-01

By the flexible mechanisms under the Kyoto Protocol are meant project-specific Joint Implementation, JI, intended for emissions reduction in the industrialised countries and the Clean Development Mechanism, CDM, designed for emissions reduction in the developing countries. Joint Implementation Projects can be found particularly in the economies-in-transition The flexible mechanisms under the Protocol also include Emissions Trading, ET, which States - and according to the view of several parties, enterprises, too - can conduct subject to rules to be later agreed upon in connection with emissions rights The international climate negotiations on the Kyoto Protocol and on drafting more detailed rules on the use of the mechanisms are still pending. In fact, the Working Group thinks that the uncertainties so far connected with the flexible mechanisms will lead to a situation in which the national climate policy must, at this stage, be primarily based on domestic reduction measures. Even if Finland were prepared to meet her climate policy obligations through domestic measures, there is, in the Working Group's opinion, skill reason to continue the preparations for the possibilities of using the Kyoto flexible mechanisms, too. The prime goal of the flexible mechanisms is an internationally cost-efficient climate policy, which creates the preconditions for the gradual tightening of emission limitations in a manner that will hinder economic and other societal activity as little as possible. Thus the flexible mechanisms can become more important during later commitment periods. According to model calculations, using the mechanisms would probably be inexpensive compared to the domestic emission reduction measures. It seems that the international markets for assigned amount units obtained through the use of the mechanisms would be big enough in view of the relatively limited immediate needs of the Finnish Climate Policy. The larger the group of countries and operators trading in

Hydro in the Kyoto era

International Nuclear Information System (INIS)

Bourdon, M.-C.

2003-01-01

Quebec has the best performance in North America in terms of greenhouse gas (GHG) emissions. Unlike neighbouring provinces and states which rely heavily on coal for power generation, Quebec generates 96 per cent of its electricity from hydroelectric power. However, no new dams have been built in the past decade in Quebec due to land disputes with Aboriginal communities and general distrust among many ecologists. It takes about 12 years for a hydroelectric project to come to fruition. For that reason, and in order to capitalize on energy market opportunities, Hydro-Quebec is seriously considering expanding its generating capability beyond the needs of Quebec consumers, with gas-fired thermal generating stations. Environmental groups claim that the proposal to build the Suroit combined-cycle facility near the United States border destroys Quebec's efforts to honour the Kyoto Protocol. Economists argue that it is entirely in the spirit of Kyoto if exports of hydroelectricity or natural gas from Canada to the United States leads to less use of oil or coal. But one energy modeling expert at INRS-Energie et Materiaux claims that Quebec has a moral obligation to develop hydroelectricity for its own use as well as for export purposes, noting that any country with the good fortune to have renewable forms of energy, such as wind and hydro, should develop them to lower world GHG emissions. Quebec has many opportunities to sell hydroelectricity even while domestic demand grows. Hydroelectricity from Quebec should interest some states that have adopted their own GHG reduction standards, despite the U.S. government's refusal to ratify Kyoto. It should also interest Ontario and the Maritimes because they will be trying to reduce emissions from their thermal plants. The current situation does not favour the Kyoto Protocol. Exports of electricity from Quebec have dropped because no new dams have been built in recent years and gas-fired plants are looking more attractive to power

Arm-length stabilisation for interferometric gravitational-wave detectors using frequency-doubled auxiliary lasers

OpenAIRE

Mullavey, Adam J.; Slagmolen, Bram J. J.; Miller, John; Evans, Matthew; Fritschel, Peter; Sigg, Daniel; Waldman, Sam J.; Shaddock, Daniel A.; McClelland, David E.

2011-01-01

Residual motion of the arm cavity mirrors is expected to prove one of the principal impediments to systematic lock acquisition in advanced gravitational-wave interferometers. We present a technique which overcomes this problem by employing auxiliary lasers at twice the fundamental measurement frequency to pre-stabilise the arm cavities’ lengths. Applying this approach, we reduce the apparent length noise of a 1.3 m long, independently suspended Fabry-Perot cavity to 30 pm rms and successfully...

Early Renal Involvement in a Girl with Classic Fabry Disease.

Science.gov (United States)

Perretta, Fernando; Antongiovanni, Norberto; Jaurretche, Sebastián

2017-01-01

Fabry disease is an X-linked lysosomal storage disorder resulting from the deficiency or absence of the enzyme alpha galactosidase A; this defect leads to the systemic accumulation of globotriaosylceramide and its metabolites. Organic involvement in men is well known, but in women it is controversial, mainly due to the random X-chromosome inactivation in each of their cells (Lyon hypothesis). This would explain why women (heterozygotes) present a wide variability in the severity of their phenotype. The manifestations are multisystemic and begin in early childhood, reaching a severe compromise in adulthood. Typical acroparesthesia in hands and feet, gastrointestinal symptoms, angiokeratomas, dyshidrosis, hearing loss, arrhythmias, hypertrophic cardiomyopathy, cerebrovascular accidents, and renal failure can be observed. Nephropathy is one of the major complications of Fabry disease. Glomerular and vascular changes are present before progression to overt proteinuria and decreased glomerular filtration rate, even in pediatric patients. A case of incipient renal involvement in a girl with classic Fabry disease is reported.

Shock loading characteristics of Zr and Ti metals using dual beam velocimeter

Energy Technology Data Exchange (ETDEWEB)

Saxena, A. K., E-mail: a-saxena@barc.gov.in; Kaushik, T. C.; Gupta, Satish C. [Applied Physics Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400 085 (India)

2015-08-21

The characteristics of titanium and zirconium metal foils under shock loading have been studied up to 16 GPa and 12 GPa pressure, respectively, using portable electric gun setup as projectile launcher. In these experiments, the capabilities of a single Fabry-Perot velocimeter have been enhanced by implementing it in dual beam mode to record the two velocity profiles on a single streak camera. The measured equation of state data for both the metals have been found to be well in agreement with the reported Hugoniot, within experimental accuracies. A phase transition from α to ω phase has been detected near to 11.4 GPa for titanium and 8.2 GPa for zirconium in the rising part of target-glass interface velocity profile.

An extraordinary transmission analogue for enhancing microwave antenna performance

Directory of Open Access Journals (Sweden)

Sarin V. Pushpakaran

2015-10-01

Full Text Available The theory of diffraction limit proposed by H.A Bethe limits the total power transfer through a subwavelength hole. Researchers all over the world have gone through different techniques for boosting the transmission through subwavelength holes resulting in the Extraordinary Transmission (EOT behavior. We examine computationally and experimentally the concept of EOT nature in the microwave range for enhancing radiation performance of a stacked dipole antenna working in the S band. It is shown that the front to back ratio of the antenna is considerably enhanced without affecting the impedance matching performance of the design. The computational analysis based on Finite Difference Time Domain (FDTD method reveals that the excitation of Fabry-Perot resonant modes on the slots is responsible for performance enhancement.

A spatio-kinematic study of the interaction of the planetary nebula NGC 246 with the interstellar medium

NARCIS (Netherlands)

Muthu, C; Anandarao, BG; Pottasch, [No Value

Spatio-Kinematic observations were made on NGC 246 in the [OIII] 5007 Angstrom line using an Imaging Fabry-Perot Spectrometer. Evidence for the deceleration effect was found in the leading edge of the nebular shell, possibly due to its interaction with the interstellar medium. Further, we show that

Where photons meet phonons

NARCIS (Netherlands)

Buters, F.M.

2017-01-01

We investigate how radiation pressure can be used to influence the mechanical motion of a micro-mirror suspended from springs. This trampoline resonator is part of an optical Fabry-Perot cavity. By tuning the laser frequency with respect to the optical resonance, we are able to optically cool the

Voltage adjusting characteristics in terahertz transmission through Fabry-Pérot-based metamaterials

Directory of Open Access Journals (Sweden)

Jun Luo

2015-10-01

Full Text Available Metallic electric split-ring resonators (SRRs with featured size in micrometer scale, which are connected by thin metal wires, are patterned to form a periodically distributed planar array. The arrayed metallic SRRs are fabricated on an n-doped gallium arsenide (n-GaAs layer grown directly over a semi-insulating gallium arsenide (SI-GaAs wafer. The patterned metal microstructures and n-GaAs layer construct a Schottky diode, which can support an external voltage applied to modify the device properties. The developed architectures present typical functional metamaterial characters, and thus is proposed to reveal voltage adjusting characteristics in the transmission of terahertz waves at normal incidence. We also demonstrate the terahertz transmission characteristics of the voltage controlled Fabry-Pérot-based metamaterial device, which is composed of arrayed metallic SRRs. To date, many metamaterials developed in earlier works have been used to regulate the transmission amplitude or phase at specific frequencies in terahertz wavelength range, which are mainly dominated by the inductance-capacitance (LC resonance mechanism. However, in our work, the external voltage controlled metamaterial device is developed, and the extraordinary transmission regulation characteristics based on both the Fabry-Pérot (FP resonance and relatively weak surface plasmon polariton (SPP resonance in 0.025-1.5 THz range, are presented. Our research therefore shows a potential application of the dual-mode-resonance-based metamaterial for improving terahertz transmission regulation.

PEMBIAYAAN RESTRUKTURISASI INDUSTRI BUS PERKOTAAN SESUAI DENGAN KERANGKA KERJA PROTOKOL KYOTO (Funding for Industrial Restructuring Urban Bus Industry following Kyoto Protocol

Directory of Open Access Journals (Sweden)

Danang Parikesit

2002-07-01

Full Text Available ABSTRAK Sektor transportasi, khususnya sektor angkutan umum telah lama disadari sebagai kontributor utama emisi gas rumah kaca (Green House Gases Emissions. Investasi pada angkutan umum perkotaan sangat dibutuhkan walaupun pembiayaan yang konvensional sering sulit dilakukan karena tingginya tingkat investasi dan prioritas pemerintah saat ini. Angkutan perkotaan juga dilihat sebagai daerah kekuasaan sektor swasta yang membuat pemerintah sulit untuk mengeluarkan uang publik. Ratifikasi Kyoto Protocol telah memberi jalan untuk mengembangkan alternatif pembiayaan untuk pembangunan yang berkelanjutan. Clean Development Mechanism pada Kyoto Protocol telah membuka kesempatan bagi otoritas angkutan umum perkotaan dengan menggunakan prinsip carbon trading. Sumber daya untuk menerapkan proyek angkutan umum perkotaan dengan CDM sangat esensial. Pekerjaan di masa datang harus diarahkan untuk mempelajari metodologi dalam mengkombinasi soft measures dan melaksanakan proyek secara optimal. Pembiayaan dengan sistem CDM ini telah dimulai di Yogyakarta dengan judul The Green House Gases Emission Reduction Program for Urban Buses in Yogyakarta atau Program Penurunan Emisi Gas Rumah Kaca untuk Bus Perkotaan di Yogyakarta. Sebuah aliansi dengan nama YUPTA (Yogyakarta Urban Public Transport Alliance telah dibentuk yang terdiri dari 3 lembaga yaitu Dinas Perhubungan Propinsi DIY, Pusat Studi Transportasi dan Logistik (PUSTRAL UGM dan Koperasi Pengusaha Angkutan Kota Yogyakarta (KOPATA.   ABSTRACT Transportation sector, especially public transportation, has been known as the main contributor to the green house hases emission. Investment to urban public transportation is needed but conventional funding is often difficult to be obtained because of the high investment level and the present government priority. Urban transportation is also seen as a private sector domain making the government difficult to use public fund. Kyoto protocol ratification has opened the way to

An all-optical fiber optic photoacoustic transducer

Science.gov (United States)

Thathachary, Supriya V.; Motameni, Cameron; Ashkenazi, Shai

2018-02-01

A highly sensitive fiber-optic Fabry-Perot photoacoustic transducer is proposed in this work. The transducer will consist of separate transmit and receive fibers. The receiver will be composed of a Fabry-Perot Ultrasound sensor with a selfwritten waveguide with all-optical ultrasound detection with high sensitivity. In previous work, we have shown an increase in resonator Q-factor from 1900 to 3200 for a simulated Fabry-Perot ultrasound detector of 45 μm thickness upon including a waveguide to limit lateral power losses. Subsequently, we demonstrated a prototype device with 30nm gold mirrors and a cavity composed of the photosensitive polymer Benzocyclobutene. This 80 µm thick device showed an improvement in its Q-factor from 2500 to 5200 after a selfaligned waveguide was written into the cavity using UV exposure. Current work uses a significantly faster fabrication technique using a combination of UV-cured epoxies for the cavity medium, and the waveguide within it. This reduces the fabrication time from several hours to a few minutes, and significantly lowers the cost of fabrication. We use a dip-coating technique to deposit the polymer layer. Future work will include the use of Dielectric Bragg mirrors in place of gold to achieve better reflectivity, thereby further improving the Q-factor of the device. The complete transducer presents an ideal solution for intravascular imaging in cases where tissue differentiation is desirable, an important feature in interventional procedures where arterial perforation is a risk. The final design proposed comprises the transducer within a guidewire to guide interventions for Chronic Total Occlusions, a disease state for which there are currently no invasive imaging options.

Implementing the Kyoto Protocol. The role of environmental agreements

Energy Technology Data Exchange (ETDEWEB)

Torvanger, Asbjoern; Skodvin, Tora

1999-09-01

This report examines under what circumstances voluntary agreements to curb greenhouse gas emissions could be an attractive policy option from the government`s perspective. The report begins by defining the term Environmental Agreement (EA) and then explores EAs in three steps: (1) Advantages and disadvantages of EAs compared to other policy tools (direct regulation, taxes and tradable permits), based on theoretical studies and experience from practical use, (2) The potential of EAs as an international policy tool, either in a bilateral or regional setting, (3) The attractiveness of EAs to implement the Kyoto Protocol, and the relation to joint implementation and international emissions trading. The main conclusions are: (1) Experience from OECD countries suggests that EAs are most attractive as a supplement to traditional command and control, or to market-based policy tools. (2) Skillful design of EAs can improve their efficiency. (3) Bilateral EAs is an interesting policy option to regulate pollution from other countries. (4) Regional EAs are rare but could have important advantages. (5) EAs can play a role in a soft transition stage from traditional command and control to domestic emission trading, and further on to a Kyoto Protocol regime of emission trading and joint implementation. 52 refs., 2 figs., 2 tabs.

What can we learn from the endogeneization of the technical progress in GEM - E3? The case of the Kyoto protocol; Que pouvons nous apprendre de l'endogeneisation du progres technique dans GEM - E3? le cas du protocole de Kyoto

Energy Technology Data Exchange (ETDEWEB)

Fougeyrollas, A.; Le Mouel, P.; Zagame, P

2007-07-01

This project aims to study how the evaluation of the policies of fight against the greenhouse effect gases emission studied at an european scale, in the framework of the Kyoto agreements, is modified when the applied model, of general equilibrium takes into account the behavior of endogenous growth described by the new theories. More specially, the authors calibrated a production module with endogenous growth properties in the model GEM-E3. The new developed module show the costs reduction of policies of greenhouse effect gases emission limitation for France and Europe. (A.L.B.)

The Kyoto Agreement: Trade and Design

DEFF Research Database (Denmark)

Svendsen, Gert Tinggaard

1999-01-01

The Kyoto Agreement from 1997 allows trade of CO2 emission quotas between the 38 industrialized countries which have committed themselves to an emission ceiling. However, it does not define how this potential trade system should be designed. The intention was to clarify these matters during the 1...

Estimating the size of the potential market for the Kyoto flexibility mechanisms

NARCIS (Netherlands)

Zhang, Z.X.

2000-01-01

The Kyoto Protocol incorporates three flexibility mechanisms to help Annex I countries to meet their Kyoto targets at a lower overall cost. This paper aims to estimate the size of the potential market for all three mechanisms over the first commitment period. Based on the national communications

High-Resolution Spectroscopy of the Lunar Sodium Exosphere

Science.gov (United States)

Mierkiewicz, E. J.; Oliversen, R. J.; Roesler, F. L.; Lupie, O. L.

2014-01-01

We have applied high-resolution Fabry-Perot spectroscopy to the study of the lunar sodium exosphere for the study of exospheric effective temperature and velocity variations. Observing from the National Solar Observatory McMath-Pierce Telescope, we used a dual-etalon Fabry-Perot spectrometer with a resolving power of 180,000 to measure line widths and Doppler shifts of the sodium D2 (5889.95 Å) emission line. Our field of view was 360 km, and measurements were made in equatorial and polar regions from 500 km to 3500 km off the limb. Data were obtained from full moon to 3 days following full moon (waning phase) in March 2009. Measured Doppler line widths within 1100 km of the sunlit east and south lunar limbs for observations between 5 and 40 deg lunar phase imply effective temperatures ranging between 3260 +/- 190 and 1000 +/- 135 K. Preliminary line center analysis indicates velocity displacements between different locations off the lunar limb ranging between 100 and 600 m/s from the lunar rest velocity with a precision of +/-20 to +/-50 m/s depending on brightness. Based on the success of these exploratory observations, an extensive program has been initiated that is expected to constrain lunar atmospheric and surface-process modeling and help quantify source and escape mechanisms.

3-D Printed Anti-Reflection Structures for the Terahertz Region

Science.gov (United States)

Bomba, Jarosław; Suszek, Jarosław; Makowski, Michał; Sobczyk, Artur; Sypek, Maciej

2018-01-01

Terahertz radiation has a growing number of applications in material characterization, where spectral fingerprinting and diffractive effects are the carriers of information. On the other hand, electromagnetic waves in the range of millimeters exhibit strong unwanted specular reflections, resulting in uncontrolled interferences. This problem is especially disturbing in the goniometric time-domain spectroscopy (TDS) configuration, where angular distribution of the field modified by the sample is altered by unwanted reflections. For this reason, low-cost anti-reflection layers are desired. Here, we present a simple way of designing and manufacturing one-sided and two-sided anti-reflection polyamide layers for the THz range. The structures were fabricated using 3-D printers based on selective laser sintering. We demonstrate experimentally in the goniometric time-domain spectroscopy the significant reduction of wavelength-dependent oscillations in Fabry-Perot configuration in the range between 0.1 and 0.3 THz. We also examine the influence of the anti-reflection layers on the distribution of THz energy in reflected, transmitted, and diffracted fields.

Cost estimation of Kyoto Protocol

International Nuclear Information System (INIS)

Di Giulio, Enzo

2005-01-01

This article proposes a reflection on important aspects in the costs determination performance of Kyoto Protocol. The evaluation of the main models evidence possible impacts on the economies. A key role in the determination of the cost is represented by the relative hypothesis to emission trading and the projects CDM-JI and from the political capacity at the cost negative or equal to zero [it

Hybrid grating reflectors: Origin of ultrabroad stopband

DEFF Research Database (Denmark)

Park, Gyeong Cheol; Taghizadeh, Alireza; Chung, Il-Sug

2016-01-01

Hybrid grating (HG) reflectors with a high-refractive-index cap layer added onto a high contrast grating (HCG) provide a high reflectance close to 100% over a broader wavelength range than HCGs. The combination of a cap layer and a grating layer brings a strong Fabry-Perot (FP) resonance as well ...

Three-dimensional face shape in Fabry disease

NARCIS (Netherlands)

Cox-Brinkman, Josanne; Vedder, Anouk; Hollak, Carla; Richfield, Linda; Mehta, Atul; Orteu, Kate; Wijburg, Frits; Hammond, Peter

2007-01-01

Facial dysmorphology is an important feature in several lysosomal storage disorders. Although in Fabry disease facial dysmorphism is not a prominent sign, minor facial abnormalities have been previously reported. By analysing three-dimensional images of faces, we quantified facial dysmorphology in a

Two roads to Kyoto: more or less

Energy Technology Data Exchange (ETDEWEB)

Stanford, J. [Canadian Auto Workers Union (Canada)

2003-01-01

According to this author, in implementing the Kyoto Protocol Canadians are faced with two alternatives: one is consuming less, driving less, and turning down the thermostat, the other is to follow the route of using energy more efficiently, which would allow us to continue to do what we like to do, including driving and staying warm in the winter. The author contends that the federal government's plan relies too heavily on moral suasion, guilt-tripping consumers into reducing their driving and reducing their GHG emissions by turning down their thermostats. The method more likely to succeed would be to encourage fuel-efficient technologies, providing incentives to promote the early commercial production in Canada of low-emission vehicles, along with tax incentives and mandatory market penetration targets. Sensible measures to push automakers to continue improving the average fuel efficiency of new vehicles, shaping and regulating the auto industry to speed up the development of hybrid fuel vehicles and other technological innovations such as continuously variable transmissions, variable valve control and direct injection technologies in engines would also advance the cause of energy efficiency. Regulations regarding motor vehicle recycling, other policies to promote steel recycling, incentives, including higher gasoline taxes, and measures which would mesh with a broader strategy to help Canadians to meet their own Kyoto challenges, are also badly needed. The right decisions on these matters will determine whether ratifying the Kyoto Protocol will be beneficial or detrimental to the Canadian economy.

Optofluidic Microlasers based on Femtosecond Micromachining Technology

Directory of Open Access Journals (Sweden)

Simoni F.

2017-08-01

Full Text Available We present the different optofluidic lasers which have been realized using the Femtosecond Micromachining technique to fabricate the monolithic optofluidic structures in glass chips. We show how the great flexibility of this 3D technique allows getting different kind of optical cavities. The most recent devices fabricated by this technique as ring shaped and Fabry-Perot resonators show excellent emission performances.We also point out how the addition of the inkjet printing technique provides further opportunities in realizing optofluidic chips.

Fabry disease, respiratory symptoms, and airway limitation

DEFF Research Database (Denmark)

Svensson, Camilla Kara; Feldt-Rasmussen, Ulla; Backer, Vibeke

2015-01-01

. The remaining 27 articles were relevant for this review. RESULTS: The current literature concerning lung manifestations describes various respiratory symptoms such as dyspnoea or shortness of breath, wheezing, and dry cough. These symptoms are often related to cardiac involvement in Fabry disease as respiratory...

Reduction of globotriaosylceramide in Fabry disease mice by substrate deprivation.

Science.gov (United States)

Abe, A; Gregory, S; Lee, L; Killen, P D; Brady, R O; Kulkarni, A; Shayman, J A

2000-06-01

We used a potent inhibitor of glucosylceramide synthase to test whether substrate deprivation could lower globotriaosylceramide levels in alpha-galactosidase A (alpha-gal A) knockout mice, a model of Fabry disease. C57BL/6 mice treated twice daily for 3 days with D-threo-1-ethylendioxyphenyl-2-palmitoylamino-3-pyrrolidi no-propanol (D-t-EtDO-P4) showed a concentration-dependent decrement in glucosylceramide levels in kidney, liver, and spleen. A single intraperitoneal injection of D-t-EtDO-P4 resulted in a 55% reduction in renal glucosylceramide, consistent with rapid renal glucosylceramide metabolism. A concentration-dependent decrement in renal and hepatic globotriaosylceramide levels was observed in alpha-Gal A(-) males treated for 4 weeks with D-t-EtDO-P4. When 8-week-old alpha-Gal A(-) males were treated for 8 weeks with 10 mg/kg twice daily, renal globotriaosylceramide fell to below starting levels, consistent with an alpha-galactosidase A-independent salvage pathway for globotriaosylceramide degradation. Complications observed with another glucosylceramide synthase inhibitor, N-butyldeoxynojirimycin, including weight loss and acellularity of lymphatic organs, were not observed with D-t-EtDO-P4. These data suggest that Fabry disease may be amenable to substrate deprivation therapy.

The Kyoto Protocol. An economic appraisal

International Nuclear Information System (INIS)

Grubb, M.

2000-05-01

This paper examines the overall economics of the Kyoto Protocol on climate change, in three main parts. The first part explores the structure of the Protocol and how this matches against classical economic criteria of an 'optimal' climate change agreement. This discussion also considers the nature of and reasons for shortcomings, and the prospects for its evolution. Given the various flexibilities in the agreement, the Kyoto Protocol is far more economically efficient in its structure than any previous global environmental agreement. The central conclusion is that, from an economic perspective, the Protocol's structure for industrialised country commitments is as good as could reasonably be expected. The second part of the paper explores more closely the economics of the commitments themselves and how they combine with the various flexibilities, briefly reviewing the available literature and using a simple spreadsheet model of how the commitments might combine with trading mechanisms under a range of assumptions. Flexibility is intrinsic and necessary, but it is argued that the allocations to Russia and Ukraine in particular mean that unlimited flexibility could render the Protocol's commitments weaker in their impacts than is economically desirable to address climate change. It is argued that, should this prove to be the case, access to the large surplus in the transition economies could be used as a control valve to limit the costs of the Protocol to within acceptable limits. Finally, the paper considers the issues of developing country involvement in the Kyoto Protocol, and the Protocol's longer-term impact and evolution, including its impact on technological evolution and dissemination and the evolution of future commitments. It is argued that taking account of such issues critically affects views of the Protocol

Kinematics of the ionized gas around the quasar MR 2251-178

NARCIS (Netherlands)

Mulder, P.S.; Valentijn, E. A.

O III forbidden line observations of the nearby quasar MR 2251-178 were made with the Taurus II imaging Fabry-Perot instrument. The line emission around the quasar is found to consist of several regions of high surface brightness located in two half-cones with an opening angle of about 37 deg

The Kyoto University tandem upgrading project

International Nuclear Information System (INIS)

Nakamura, Masanobu; Shimoura, Susumu; Takimoto, Kiyohiko; Sakaguchi, Harutaka; Kobayashi, Shinsaku

1988-01-01

A brief description on the Kyoto University tandem upgrading project. The project consists of replacing the old 5 MV tandem Van de Graaff by an 8UDH pelletron. The old pressure vessel and beam lines are used again without significant modification. The project is planned to be completed at the end of 1989. (orig.)

Fossil fuels: Kyoto initiatives and opportunities. Part 1

International Nuclear Information System (INIS)

Pinelli, G.; Zerlia, T.

2008-01-01

GHG emission in the upstream step of fossil fuel chains could give an environmental as well as economic opportunity for traditional sectors. This study deepens the matter showing an increasing number of initiative over the last few years taken both the involved sectors and by various stake holders (public and private subjects) within the Kyoto flexible mechanism (CDM and JI) or linked to voluntary national or at a global level actions. The above undertakings give evidence for an increased interest and an actual activity dealing with GHG reduction whose results play an evident and positive role for the environment too. Part 1. of this study deals with fossil fuel actions within the Kyoto protocol mechanism. Part 2. will show international and national voluntary initiative [it

Screening for Fabry's disease in young patients with ischemic stroke in a Chinese population.

Science.gov (United States)

Song, Xiaowei; Xue, Sufang; Zhao, Jingyan; Wu, Jian

2017-04-01

Fabry disease is an X-linked lysosomal storage disorder frequently associated with cerebrovascular disease. Data regarding Fabry disease and ischemic stroke has been lacking in China. In this study, we investigated the prevalence of Fabry disease and the distribution of the alpha-galactosidase A (α-GalA) gene - GLA mutations in young stroke patients in the Chinese population and its association with stroke subtypes. A total of 357 ischemic stroke patients admitted to Xuanwu Hospital of Capital Medical University, aged 18-55 years old, including 293 patients with cerebral infarction and 64 patients with transient ischemic attack, were enrolled in this study. Mutations in the GLA gene were screened by Sanger sequencing. Enzyme levels were measured to further confirm the disease in patients with the gene mutation. The mutation frequency was compared among different stroke subtypes and further compared with the control group individually. No pathogenic mutations in the coding regions of the GLA gene were identified in this group of patients and thus no Fabry disease was found in our study. However, the frequency of an intronic polymorphism c.-10C>T was significantly different among different Trial of Org 10172 in Acute Stroke Treatment subtypes (p T polymorphism in patients with stroke due to other causes and undetermined causes was much higher than that in the control group (OR = 3.18, 95% CI: 1.29-7.83, p stroke patients. In addition, our results suggested that the c.-10C>T polymorphism may be a risk factor for ischemic stroke of other and undetermined causes. Further study is required to confirm our findings.

Diamond-based Fabry-Perot microcavities for quantum networks

NARCIS (Netherlands)

Bogdanovic, S.

2017-01-01

A quantumnetwork would allow the distribution of a quantum state over many spatially separated quantum nodes which individually possess the ability to generate, process and store quantum information. Connecting these nodes through quantum communication channels would enable sending quantum

Fabry-Perot MEMS Accelerometers for Advanced Seismic Imaging

Energy Technology Data Exchange (ETDEWEB)

Chisum, Brad [Lumedyne Technologies Incorporated, San Diego, CA (United States)

2015-05-31

This report summarizes the technical achievements that occurred over the duration of the project. On November 14th, 2014, Lumedyne Technologies Incorporated was acquired. As a result of the acquisition, the work toward seismic imaging applications was suspended indefinitely. This report captures the progress achieved up to that time.

Submission under the United Nations framework convention on climate change and the Kyoto protocol 2011. National inventory report for the German greenhouse gas inventory 1990-2009; Berichterstattung unter der Klimarahmenkonvention der Vereinten Nationen und dem Kyoto-Protokoll 2011. Nationaler Inventarbericht zum Deutschen Treibhausgasinventar 1990-2009

Energy Technology Data Exchange (ETDEWEB)

NONE

2011-06-15

development of emissions of direct and indirect greenhouse gases and of storage of carbon dioxide in sinks. Chapters 3 to 9 present information about the individual source and sink groups. Along with general descriptions and information relative to the methods used, the sub-chapters also include information about pertinent uncertainties, quality assurance and quality control, recalculations carried out and planned improvements for relevant source and sink categories. More-detailed information about recalculations, and information relative to the improvements and changes made with regard to the last greenhouse-gas inventory, is presented in Chapter 10. Part II of the NIR, in Chapters 11 to 16, presents the so-called ''Kyoto-NIR'', in fulfillment of the expanded requirements for Kyoto reporting, and in keeping with the required organisation (annotated NIR). Chapter 11 contains all information relative to Kyoto reporting in the areas of land use, land use changes and forestry (LULUCF), especially the definition of ''forest'' chosen, details on the land-classification technique used and all information relative to selected activities pursuant to Arts. 3.3 and 3.4 of the Kyoto Protocol. Chapter 12 is devoted completely to accounting for Kyoto units, a process for which, in Germany, the German Emissions Trading Authority (DEHSt) is responsible. Chapters 13 and 14 provide an overview of changes made in the National System, and at the German Emissions Trading Authority, with the aim of ruling out the possibility of any undue influences on Kyoto reporting. Chapter 15 lists all the measures that Germany is taking to minimise negative impacts pursuant to Article 3 (14). Chapter 16 presents any required further information relative to Kyoto reporting. Annexes 1 through 7, in Chapters 17-23, presented more-detailed descriptions of key categories, of individual source categories, of the CO2-reference procedure, of completeness issues, of the National

Submission under the United Nations framework convention on climate change and the Kyoto protocol 2011. National inventory report for the German greenhouse gas inventory 1990-2009; Berichterstattung unter der Klimarahmenkonvention der Vereinten Nationen und dem Kyoto-Protokoll 2011. Nationaler Inventarbericht zum Deutschen Treibhausgasinventar 1990-2009

Energy Technology Data Exchange (ETDEWEB)

NONE

2011-06-15

emissions of direct and indirect greenhouse gases and of storage of carbon dioxide in sinks. Chapters 3 to 9 present information about the individual source and sink groups. Along with general descriptions and information relative to the methods used, the sub-chapters also include information about pertinent uncertainties, quality assurance and quality control, recalculations carried out and planned improvements for relevant source and sink categories. More-detailed information about recalculations, and information relative to the improvements and changes made with regard to the last greenhouse-gas inventory, is presented in Chapter 10. Part II of the NIR, in Chapters 11 to 16, presents the so-called ''Kyoto-NIR'', in fulfillment of the expanded requirements for Kyoto reporting, and in keeping with the required organisation (annotated NIR). Chapter 11 contains all information relative to Kyoto reporting in the areas of land use, land use changes and forestry (LULUCF), especially the definition of ''forest'' chosen, details on the land-classification technique used and all information relative to selected activities pursuant to Arts. 3.3 and 3.4 of the Kyoto Protocol. Chapter 12 is devoted completely to accounting for Kyoto units, a process for which, in Germany, the German Emissions Trading Authority (DEHSt) is responsible. Chapters 13 and 14 provide an overview of changes made in the National System, and at the German Emissions Trading Authority, with the aim of ruling out the possibility of any undue influences on Kyoto reporting. Chapter 15 lists all the measures that Germany is taking to minimise negative impacts pursuant to Article 3 (14). Chapter 16 presents any required further information relative to Kyoto reporting. Annexes 1 through 7, in Chapters 17-23, presented more-detailed descriptions of key categories, of individual source categories, of the CO2-reference procedure, of completeness issues, of the National System and the Quality System, of the CSE emissions

An overview of the DII-HEP OpenStack based CMS data analysis

Science.gov (United States)

Osmani, L.; Tarkoma, S.; Eerola, P.; Komu, M.; Kortelainen, M. J.; Kraemer, O.; Lindén, T.; Toor, S.; White, J.

2015-05-01

An OpenStack based private cloud with the Cluster File System has been built and used with both CMS analysis and Monte Carlo simulation jobs in the Datacenter Indirection Infrastructure for Secure High Energy Physics (DII-HEP) project. On the cloud we run the ARC middleware that allows running CMS applications without changes on the job submission side. Our test results indicate that the adopted approach provides a scalable and resilient solution for managing resources without compromising on performance and high availability. To manage the virtual machines (VM) dynamically in an elastic fasion, we are testing the EMI authorization service (Argus) and the Execution Environment Service (Argus-EES). An OpenStackplugin has been developed for Argus-EES. The Host Identity Protocol (HIP) has been designed for mobile networks and it provides a secure method for IP multihoming. HIP separates the end-point identifier and locator role for IP address which increases the network availability for the applications. Our solution leverages HIP for traffic management. This presentation gives an update on the status of the work and our lessons learned in creating an OpenStackbased cloud for HEP.

Lasing in ZnO and CdS nanowires

Energy Technology Data Exchange (ETDEWEB)

Thielmann, Andreas; Geburt, Sebastian; Kozlik, Michael; Kuehnel, Julian; Borschel, Christian; Ronning, Carsten [Institut fuer Festkoerperphysik, Friedrich-Schiller-Universitaet Jena, Max-Wien-Platz 1, 07743 Jena (Germany)

2011-07-01

The development of nanoscaled semiconductor lasers could be the key resolution to the still persistent size mismatch between integrated microelectronic devices and semiconductor optoelectronic devices. Semiconductor nanowires offer an elegant path to the development of nanoscaled lasers as their geometry with two planar end facets naturally combines a fiber-like waveguide with an optical resonator. The possible stimulation of the material's emission processes enables lasing of resonant optical modes. ZnO and CdS nanowires of different aspect ratios have been synthesized via the VLS mechanism and were characterized by SEM, EDX and ensemble PL measurements. Power dependent PL measurements on single nanowires excited with pulsed laser light at 355 nm have been performed between 10 K and room temperature and were set in correlation to the nanowires' respective morphology. Sharp emission lines which show characteristics of Fabry-Perot modes could be observed above a power threshold. The measured power dependencies reveal amplified stimulated emission and lasing at high excitation densities.

Narrow linewidth operation of the RILIS titanium: Sapphire laser at ISOLDE/CERN

CERN Document Server

Rothe, S; Wendt, K D A; Fedosseev, V N; Kron, T; Marsh, B A

2013-01-01

A narrow linewidth operating mode for the Ti:sapphire laser of the CERN ISOLDE Resonance Ionization Laser Ion Source (RILIS) has been developed. This satisfies the laser requirements for the programme of in-source resonance ionization spectroscopy measurements and improves the selectivity for isomer separation using RILIS. A linewidth reduction from typically 10 GHz down to 1 GHz was achieved by the intra-cavity insertion of a second (thick) Fabry-Perot etalon. Reliable operation during a laser scan was achieved through motorized control of the tilt angle of each etalon. A scanning, stabilization and mode cleaning procedure was developed and implemented in LabVIEW. The narrow linewidth operation was confirmed in a high resolution spectroscopy study of francium isotopes by the Collinear Resonance Ionization Spectroscopy experiment. The resulting laser scans demonstrate the suitability of the laser, in terms of linewidth, spectral purity and stability for high resolution in-source spectroscopy and isomer select...

Lasing in liquid crystal thin films

Energy Technology Data Exchange (ETDEWEB)

Palto, S. P. [Russian Academy of Sciences, Shubnikov Institute of Crystallography (Russian Federation)], E-mail: palto@online.ru

2006-09-15

A lasing condition is formulated in matrix form for optically anisotropic thin films. Lasing behavior of liquid-crystal slabs is analyzed. In particular, it is shown that if the spatial extent of a liquid crystal slab is much larger than its thickness, then laser emission is feasible not only along the normal to the slab, but also in the entire angular sector. The generated laser light can be observed experimentally as a spot or as concentric rings on a screen. The lowest lasing threshold corresponds to in-plane sliding modes leaking into the substrate. The feedback required for lasing is provided by reflection from the interfaces, rather than edges, of the liquid-crystal slab operating as a planar Fabry-Perot cavity. For cholesteric liquid crystals, it is shown that energy loss to the sliding modes leaking into the substrates and escaping through their edges is a key factor that limits the efficiency of band-edge emission along the normal to the slab.

Interplay of Chiral and Helical States in a Quantum Spin Hall Insulator Lateral Junction

Science.gov (United States)

Calvo, M. R.; de Juan, F.; Ilan, R.; Fox, E. J.; Bestwick, A. J.; Mühlbauer, M.; Wang, J.; Ames, C.; Leubner, P.; Brüne, C.; Zhang, S. C.; Buhmann, H.; Molenkamp, L. W.; Goldhaber-Gordon, D.

2017-12-01

We study the electronic transport across an electrostatically gated lateral junction in a HgTe quantum well, a canonical 2D topological insulator, with and without an applied magnetic field. We control the carrier density inside and outside a junction region independently and hence tune the number and nature of 1D edge modes propagating in each of those regions. Outside the bulk gap, the magnetic field drives the system to the quantum Hall regime, and chiral states propagate at the edge. In this regime, we observe fractional plateaus that reflect the equilibration between 1D chiral modes across the junction. As the carrier density approaches zero in the central region and at moderate fields, we observe oscillations in the resistance that we attribute to Fabry-Perot interference in the helical states, enabled by the broken time reversal symmetry. At higher fields, those oscillations disappear, in agreement with the expected absence of helical states when band inversion is lifted.

The D313Y variant in the GLA gene - no evidence of a pathogenic role in Fabry disease

DEFF Research Database (Denmark)

Hasholt, Lis; Ballegaard, Martin; Bundgaard, Henning

2017-01-01

Fabry disease is an X- linked inherited lysosomal storage disease caused by mutations in the GLA gene encoding the lysosomal enzyme alpha-galactosidase A (α-Gal A). The possible pathological significance of the D313Y variant in the GLA gene has not been verified and it may be a Fabry variant. Our......, and the presence in Fabry females did not significantly enhance the phenotype of a known causative mutation in the GLA gene (G271S). Our findings indicate that the D313Y variant is not causative to nor enhancing Fabry disease phenotype. The D313Y variant in the GLA gene was not disease causative in 2 Danish...... families. Investigating male family members were crucial in excluding the Fabry phenotype, and thus very important for proper genetic counceling of all family members, as well as overdiagnosing a devastating genetic disease....

Science Hall of Atomic Energy in Research Reactor Institute, Kyoto University

International Nuclear Information System (INIS)

Hayashi, Takeo

1979-01-01

The Science Hall of Atomic Energy was built as a subsidiary facility of the Research Reactor Institute, Kyoto University. The purpose of this facility is to accept outside demands concerning the application of the research reactor. The building is a two story building, and has the floor area of 901.47 m 2 . There are an exhibition room, a library, and a big lecture room. In the exhibition room, models of the Kyoto University Research Reactor and the Kyoto University Critical Assembly are placed. Various pictures concerning the application of the reactor are on the wall. In the library, people from outside of the Institute can use various books on science. Books for boys and girls are also stocked and used for public use. At the lecture room, various kinds of meeting can be held. (Kato, T.)

Hearing loss in children with Fabry disease

NARCIS (Netherlands)

Suntjens, E.; Dreschler, W. A.; Hess-Erga, J.; Skrunes, R.; Wijburg, F. A.; Linthorst, G. E.; Tøndel, C.; Biegstraaten, M.

2017-01-01

Background Hearing loss (HL) is a well-known feature of Fabry disease (FD). Its presence and characteristics have mainly been studied in adult patients, while only limited data are available on the presence and degree of HL in children with FD. This prompted us to study hearing sensitivity in

The Kyoto protocol becomes effective - implications for french forests

International Nuclear Information System (INIS)

Chaudron, Alain; Morel, Michel-Paul; Merckx, Valerie; Gaborit, Guillaume

2005-01-01

The Kyoto Protocol came into force on February 16, 2005. The article takes stock of ongoing processes and their consequences for French forests. It first describes the Kyoto Protocol and the framework agreement on climate change from which it is derived, then the particular implementing regulations for forestry stakeholders and the detailed rules for applying it to French forests, and specifically the complex accounting rules that arose from negotiations, and finally the future outlook of these processes that have been regularly revised at annual meetings and will continue to be developed. Indeed, the international dialogue concerning the post-2012 era has already begun. (authors)

Elevated globotriaosylsphingosine is a hallmark of Fabry disease

NARCIS (Netherlands)

Aerts, Johannes M.; Groener, Johanna E.; Kuiper, Sijmen; Donker-Koopman, Wilma E.; Strijland, Anneke; Ottenhoff, Roelof; van Roomen, Cindy; Mirzaian, Mina; Wijburg, Frits A.; Linthorst, Gabor E.; Vedder, Anouk C.; Rombach, Saskia M.; Cox-Brinkman, Josanne; Somerharju, Pentti; Boot, Rolf G.; Hollak, Carla E.; Brady, Roscoe O.; Poorthuis, Ben J.

2008-01-01

Fabry disease is an X-linked lysosomal storage disease caused by deficiency of alpha-galactosidase A that affects males and shows disease expression in heterozygotes. The characteristic progressive renal insufficiency, cardiac involvement, and neuropathology usually are ascribed to

the central europe and the Kyoto protocol on the climatic changes

International Nuclear Information System (INIS)

Mariotte, C.

2006-01-01

This book presents little known aspects of the Kyoto protocol concerning the Central Europe or Visegrad Group and analyzes the environmental problem in a context of political transitions. The impacts of the Kyoto protocol and more especially the pollution permits market, on these countries are presented. It precises the shadow zones, the hope and the great willingness which qualify this great project and which are poorly discussed by the economists. (A.L.B.)

Protocolos de Montreal e Kyoto: pontos em comum e diferenças fundamentais Montreal and Kyoto Protocols: common points and essential differences

Directory of Open Access Journals (Sweden)

Darly Henriques da Silva

2009-12-01

Full Text Available Os Protocolos de Montreal e Kyoto, tratados internacionais de defesa do meio ambiente e da vida, controlam gases que provocam o buraco na camada de ozônio e o efeito estufa, respectivamente, resultantes de atividades industriais e uso da terra. O artigo enfatiza pontos comuns e diferenças entre eles, fornecendo atualização dos protocolos.Montreal and Kyoto Protocols, international treaties, aim at safeguarding the environment and life by controlling the use of gases which deplete the ozone layer and cause the greenhouse effect, respectively, due to industrial and land use activities. The article highlights common points and differences and provides an update discussion about the protocols.

AB018. Revisited later-onset cardiac type Fabry disease—cardiac damages progressed in silence—experiences from an extremely high prevalent area, Taiwan

OpenAIRE

Niu, Dau-Ming; Hsu, Ting-Rong; Yang, Chia-Feng; Chu, Tzu-Hung; Chiang, Chuan-Chi; Ho, Hui-Chen

2015-01-01

All of the current newborn screening studies of Fabry disease revealed that the incidences of later-onset Fabry disease in their studied populations were much higher than the previous expectancy. It reveals that later-onset Fabry disease could be an important hidden health issue in some populations or even a lot of populations. However, the natural course of later-onset Fabry disease is still largely unknown. A total of 792,247 newborns have been screened for Fabry disease by our team in Taiw...

Lentivector Iterations and Pre-Clinical Scale-Up/Toxicity Testing: Targeting Mobilized CD34+ Cells for Correction of Fabry Disease

Directory of Open Access Journals (Sweden)

Ju Huang

2017-06-01

Full Text Available Fabry disease is a rare lysosomal storage disorder (LSD. We designed multiple recombinant lentivirus vectors (LVs and tested their ability to engineer expression of human α-galactosidase A (α-gal A in transduced Fabry patient CD34+ hematopoietic cells. We further investigated the safety and efficacy of a clinically directed vector, LV/AGA, in both ex vivo cell culture studies and animal models. Fabry mice transplanted with LV/AGA-transduced hematopoietic cells demonstrated α-gal A activity increases and lipid reductions in multiple tissues at 6 months after transplantation. Next we found that LV/AGA-transduced Fabry patient CD34+ hematopoietic cells produced even higher levels of α-gal A activity than normal CD34+ hematopoietic cells. We successfully transduced Fabry patient CD34+ hematopoietic cells with “near-clinical grade” LV/AGA in small-scale cultures and then validated a clinically directed scale-up transduction process in a GMP-compliant cell processing facility. LV-transduced Fabry patient CD34+ hematopoietic cells were subsequently infused into NOD/SCID/Fabry (NSF mice; α-gal A activity corrections and lipid reductions were observed in several tissues 12 weeks after the xenotransplantation. Additional toxicology studies employing NSF mice xenotransplanted with the therapeutic cell product demonstrated minimal untoward effects. These data supported our successful clinical trial application (CTA to Health Canada and opening of a “first-in-the-world” gene therapy trial for Fabry disease.

Kyoto protocol and its implementation in pakistan: hurdles and expectations

International Nuclear Information System (INIS)

Iqbal, S.; Sher, H.A.; Qureshi, S.A

2010-01-01

In 1997 Kyoto protocol was adopted at the third session of Conference of the parties of UNFCC in Kyoto, Japan. This protocol restricts the industrialized countries and those in transition to a market economy agreed to limit or reduce their emissions. In Pakistan the government is also taking steps to reduce the pollution. This paper discusses the possible low carbon emitting electricity generation options by keeping in view the current energy scenario of Pakistan and the new energy policy announced by the Government of Pakistan for renewable energy promotion. (author)

Pulse reshaping in photonic crystal waveguides and microcavities with Kerr nonlinearity: Critical issues for all-optical switching

International Nuclear Information System (INIS)

Vujic, Dragan; John, Sajeev

2005-01-01

We delineate critical issues for 'controlling light with light' in photonic crystal (PC) waveguides coupled to Kerr-nonlinear microresonators. These arise from (a) fundamental trade-off between switching speed and switching intensity threshold inherent in high-quality Q-factor cavities and (b) the dynamical nonlinear oscillation of such cavities in response to incident light pulses. Using finite-difference time-domain simulations of electromagnetic pulse propagation, we consider both (i) a nonlinear Fabry-Perot microresonator (embedded within a PC waveguide) exhibiting a narrow transmission resonance and (ii) a nonlinear point defect (side-coupled to a PC waveguide) exhibiting a narrow reflection spectrum. We describe self-induced switching from transmission to reflection induced by pulse intensity tuning as well as control of pulse transmission induced by the secondary, continuous (cw) laser field propagating through the same PC waveguide. For the Fabry-Perot microresonator, a well-defined self-switching threshold is obtained. However, this is accompanied by considerable temporal and spectral distortion of the pulse caused by the oscillatory nonlinear response of the microresonator. When the quality factor of the microresonator is increased, the switching intensity threshold can be lowered but the pulse transit (switching) time and the pulse distortion are increased. For the side-coupled microresonator, a gradual (not sharp) self-switching behavior as a function of incident intensity is obtained. For both the Fabry-Perot and side-coupled nonlinear microresonators, control of pulse transmission can be achieved by means of a secondary cw laser field. The cw power required for switching with realistic Kerr nonlinearities is in excess of 1 W/μm 2 and may cause optical damage to the semiconducting PC backbone. Both instantaneous and noninstantaneous Kerr-response models are considered. Our results underscore the limitations and trade-offs inherent in the possible

Photodetachment spectroscopy and microscopy, measurement of the photodetachment cross section of H- at 1064 nm by the observation of the asymptotic behaviour in the saturated regime

International Nuclear Information System (INIS)

Vandevraye, M.

2013-01-01

In this thesis, we initiate the demonstration, at a reduced scale, of the feasibility of the almost-complete laser photodetachment of negative hydrogen ion beams in a Fabry-Perot optical cavity for future neutral beam injectors for the heating of fusion power plants plasmas. We develop a new method to measure a photodetachment cross section, the knowledge of which at the exciting wavelength is needed to scale the Fabry-Perot cavity, based on the observation of the saturation in a pulsed lighting regime. The analytical calculus of the detachment signal growth produced while illuminating a negative ion beam with a Gaussian laser pulse bring out a mathematical constraint on the required flux to pass through the saturated regime. This constraint is the signature of the transition toward the saturation for all experiment carried out in Gaussian beam and for all linear light-matter interaction processes. With this method, we measure the photodetachment cross section of H - at 1064 nm - selected wavelength for future neutral beam injectors - we get 5.0*10 -21 m 2 in slight disagreement with theoretical predictions. To reduce the technological requirement on the Fabry-Perot cavity and the laser, we study Landau resonances which appear in the photodetachment spectrum. Locking the laser on one of these resonances would allow increasing the photodetachment probability at a given flux. We also present our phosphorus, selenium and tin electron affinity measurements carried out with the photodetachment microscope. We get the following values: 6021.81(8) cm -1 for P, 16297.276(9) cm -1 for Se and 8969.447(13) cm -1 . The photodetachment microscopy experiment of phosphorus is the first one where the neutral atom is left in an excited term. (author)

Dynamics of a barium release in the magnetospheric tail

Science.gov (United States)

Mende, S. B.; Swenson, G. R.; Geller, S. P.; Doolittle, J. H.; Haerendel, G.

1989-01-01

The late time behavior of the May 13, 1985 magnetotail barium cloud is examined. The bulk dynamics of the cloud are studied based on triangulated data and data from Fabry-Perot Doppler velocity measurements. The changes in cloud morphology in relation to the in situ measurements made by the Ion Release Module satellite are discussed.

Detonation in TATB Hemispheres

Energy Technology Data Exchange (ETDEWEB)

Druce, B; Souers, P C; Chow, C; Roeske, F; Vitello, P; Hrousis, C

2004-03-17

Streak camera breakout and Fabry-Perot interferometer data have been taken on the outer surface of 1.80 g/cm{sup 3} TATB hemispherical boosters initiated by slapper detonators at three temperatures. The slapper causes breakout to occur at 54{sup o} at ambient temperatures and 42{sup o} at -54 C, where the axis of rotation is 0{sup o}. The Fabry velocities may be associated with pressures, and these decrease for large timing delays in breakout seen at the colder temperatures. At room temperature, the Fabry pressures appear constant at all angles. Both fresh and decade-old explosive are tested and no difference is seen. The problem has been modeled with reactive flow. Adjustment of the JWL for temperature makes little difference, but cooling to -54 C decreases the rate constant by 1/6th. The problem was run both at constant density and with density differences using two different codes. The ambient code results show that a density difference is probably there but it cannot be quantified.

Detonation in TATB hemispheres

Energy Technology Data Exchange (ETDEWEB)

Druce, Robert L.; Souers, P. Clark; Chow, Charles; Roeske, Franklin; Vitello, Peter; Hrousis, Constantine [Lawrence Livermore National Laboratory, Livermore, CA, 94550 (United States)

2005-04-01

Streak camera breakout and Fabry-Perot interferometer data have been taken on the outer surface of 1.80 g/cm{sup 3} TATB (triamino-trinitrobenzene) hemispherical boosters initiated by slapper detonators at three temperatures. The slapper causes breakout to occur at 54 at ambient temperatures and 42 at -54 C, where the axis of rotation is 0 . The Fabry velocities may be associated with pressures, and these decrease for large timing delays in breakout seen at the colder temperatures. At room temperature, the Fabry pressures appear constant at all angles. Both fresh and decade-old explosive are tested and no difference is seen. The problem has been modeled with reactive flow. Adjustment of the JWL for temperature makes little difference, but cooling to -54 C decreases the rate constant by 1/6th. The problem was run both at constant density and with density differences using two different codes. The ambient code results show that a density difference is probably present, but it cannot be quantified. (Abstract Copyright [2005], Wiley Periodicals, Inc.)

The Kyoto Protocol Emissions Trading Mechanisms - A Model for financing future nuclear development in Romania

International Nuclear Information System (INIS)

Purica, Ionut; John Saroudis

2001-01-01

At the beginning of 2001 Romania ratified the Kyoto Protocol (Law 3/2001) thus becoming the first European country to do so. The mechanisms of the Kyoto Protocol are now opening new ways to sponsor the financing of nuclear projects. In May 2001 Societatea Nationala Nuclearoelectrica S.S. (SNN) and Atomic Energy of Canada Limited and ANSALDO of Italy signed a contract to complete the second CANDU unit at Cernavoda thus giving a new momentum to the nuclear program in Romania. The Government of Romania has indicated its desire to proceed with the completion of the other units on the Cernavoda site and is open to explore every potential financing mechanism to make this a reality. Although the Kyoto Protocol was not ratified by those countries that have the greatest need to reduce emissions, a market for emissions trading has developed, Canada being one of the important players in this market. Since the emission reduction per dollar invested in the Romanian nuclear program would bring much more reduction than the marginal reduction per dollar invested in environmental protection programs in Canada, where the saturation effect is already taking place, we consider that the application of the Kyoto Protocol mechanisms represents a realistic source for a sustainable cooperation of the two countries. This trend is in line with the latest activities of the International Atomic Energy Agency (IAEA). This paper analyzes the impact that the use of emissions credits would have on a typical financing scheme for a future CANDU project in Romania given the present situation and also proposes a model for the structure of the emissions trade that would generate a source of funding for the project. The conclusion is that there is real potential in using Kyoto Protocol mechanisms for financing nuclear development with benefits for both Romania and Canada. (authors)

Climate policy after Kyoto

International Nuclear Information System (INIS)

Gerholm, T.R.

2002-01-01

The Kyoto Convention recommends reductions in emissions of CO 2 and other greenhouse gases, to mitigate the rate of climate change. Lively debate has taken place in many countries, not least over the political and economic implications. The basis for the Kyoto discussions was a set of studies commissioned, compiled and published by the UN's International Panel on Climate Change (IPCC). At first glance this scientific foundation plainly shows that significant climate change will occur unless emissions of greenhouse gases are sharply curtailed. On closer examination, the scientific evidence provided in the IPCC material is far from clear. Reputable scientists have expressed critical views about the interpretation of the scientific results and, even more, of the way the material is being used for policy purposes. The main purpose of this book is to voice this critique. To give the reader some context, a central section from the IPCC's basic document is presented first. There follow nine papers, by prominent natural and social scientists, in which the reasons for their sceptical attitudes are developed. A final paper by Professor Bert Bolin, chairman of the IPCC during the time when most of the material was produced, provides a response and commentary to the critique. The aim of the editor and authors, in presenting the material in this way, rather than as a polemical tract, is to leave open to the reader the question: Is global warming a consequence of man's activities, or are there other reasons; if so, is adopting policies with significant economic consequences, a reasonable response? (Author)

Fabry-Pérot Oscillation and Room Temperature Lasing in Perovskite Cube-Corner Pyramid Cavities

KAUST Repository

Mi, Yang; Liu, Zhixiong; Shang, Qiuyu; Niu, Xinxiang; Shi, Jia; Zhang, Shuai; Chen, Jie; Du, Wenna; Wu, Zhiyong; Wang, Rui; Qiu, Xiaohui; Hu, Xiaoyong; Zhang, Qing; Wu, Tao; Liu, Xinfeng

2018-01-01

Recently, organometal halide perovskite-based optoelectronics, particularly lasers, have attracted intensive attentions because of its outstanding spectral coherence, low threshold, and wideband tunability. In this work, high-quality CH3 NH3 PbBr3 single crystals with a unique shape of cube-corner pyramids are synthesized on mica substrates using chemical vapor deposition method. These micropyramids naturally form cube-corner cavities, which are eminent candidates for small-sized resonators and retroreflectors. The as-grown perovskites show strong emission ≈530 nm in the vertical direction at room temperature. A special Fabry-Pérot (F-P) mode is employed to interpret the light confinement in the cavity. Lasing from the perovskite pyramids is observed from 80 to 200 K, with threshold ranging from ≈92 µJ cm-2 to 2.2 mJ cm-2 , yielding a characteristic temperature of T0 = 35 K. By coating a thin layer of Ag film, the threshold is reduced from ≈92 to 26 µJ cm-2 , which is accompanied by room temperature lasing with a threshold of ≈75 µJ cm-2 . This work advocates the prospect of shape-engineered perovskite crystals toward developing micro-sized optoelectronic devices and potentially investigating light-matter coupling in quantum optics.

Fabry-Pérot Oscillation and Room Temperature Lasing in Perovskite Cube-Corner Pyramid Cavities

KAUST Repository

Mi, Yang

2018-01-10

Recently, organometal halide perovskite-based optoelectronics, particularly lasers, have attracted intensive attentions because of its outstanding spectral coherence, low threshold, and wideband tunability. In this work, high-quality CH3 NH3 PbBr3 single crystals with a unique shape of cube-corner pyramids are synthesized on mica substrates using chemical vapor deposition method. These micropyramids naturally form cube-corner cavities, which are eminent candidates for small-sized resonators and retroreflectors. The as-grown perovskites show strong emission ≈530 nm in the vertical direction at room temperature. A special Fabry-Pérot (F-P) mode is employed to interpret the light confinement in the cavity. Lasing from the perovskite pyramids is observed from 80 to 200 K, with threshold ranging from ≈92 µJ cm-2 to 2.2 mJ cm-2 , yielding a characteristic temperature of T0 = 35 K. By coating a thin layer of Ag film, the threshold is reduced from ≈92 to 26 µJ cm-2 , which is accompanied by room temperature lasing with a threshold of ≈75 µJ cm-2 . This work advocates the prospect of shape-engineered perovskite crystals toward developing micro-sized optoelectronic devices and potentially investigating light-matter coupling in quantum optics.

Spectrally resolved measurement of the ion feature in the scattered spectrum of a hydrogen plasma obtained with a periodically pulsed Nd3+: YAG-laser

International Nuclear Information System (INIS)

Kasparek, W.

Ion temperature and density in a magnetically stabilized hydrogen arc were determined with laser scattering from collective electron density fluctuations. A 90 0 -scattering experiment was set up using a periodically pulsed Nd 3+ : YAG-laser, an IR-photomultiplier and synchronous signal detection. A spectral resolution of 0.3 Angstroem was achieved by narrowing the laser line width and by using a Fabry-Perot-interferometer in combination with a monochromator as spectrometer. The data obtained from the scattered spectra (Tsub(i) = 1,1 ... 1,8 eV, nsub(e) = 2 ... 6 x 10 21 m -3 ) agree well with those obtained by other methods. The achieved high resolution also allowed to measure separately the ion features of two ion species with different mass, which are spectrally distinguished from each other. The results confirm the theoretical model of Evans. Demixing effects in a H 2 /A mixture as well as a temperature difference between the ion sorts are deduced. (orig.) 891 HT/orig. 892 HIS

Theoretical simulations of protective thin film Fabry-Pérot filters for integrated optical elements of diode pumped alkali lasers (DPAL

Directory of Open Access Journals (Sweden)

L. Quarrie

2014-09-01

Full Text Available The lifetime of Diode-Pumped Alkali Lasers (DPALs is limited by damage initiated by reaction of the glass envelope of its gain medium with rubidium vapor. Rubidium is absorbed into the glass and the rubidium cations diffuse through the glass structure, breaking bridging Si-O bonds. A damage-resistant thin film was developed enhancing high-optical transmission at natural rubidium resonance input and output laser beam wavelengths of 780 nm and 795 nm, while protecting the optical windows of the gain cell in a DPAL. The methodology developed here can be readily modified for simulation of expected transmission performance at input pump and output laser wavelengths using different combination of thin film materials in a DPAL. High coupling efficiency of the light through the gas cell was accomplished by matching the air-glass and glass-gas interfaces at the appropriate wavelengths using a dielectric stack of high and low index of refraction materials selected to work at the laser energies and protected from the alkali metal vapor in the gain cell. Thin films as oxides of aluminum, zirconium, tantalum, and silicon were selected allowing the creation of Fabry-Perot optical filters on the optical windows achieving close to 100% laser transmission in a solid optic combination of window and highly reflective mirror. This approach allows for the development of a new whole solid optic laser.

FOR INFORMATION: GENEVA UNIVERSITY

CERN Multimedia

2006-01-01

Ecole de physique - Département de physique nucléaire et corspusculaire 24, Quai Ernest-Ansermet - 1211 GENEVE 4TéL: (022) 379 62 73 - Fax: (022) 379 69 92 Wednesday 15 March PARTICLE PHYSICS SEMINAR at 17:00 - Stückelberg Auditorium PVLAS, an experiment to probe vacuum with polarized light: results and prospects by Prof. Ugo Gastaldi / Laboratori Nazionali di Legnaro, Italy The PVLAS experiment operates at LNL an ellipsometer (with a 6m long vertical Fabry-Perot cavity which embraces a rotating 5.5 Tesla superconducting dipole magnet) that can measure ellipticity and rotation induced by the magnetic field onto linearly polarized laser light. The sensitivity of the instrument is of the order of 10-7rad sqrtHz-1 with infrared light stored in the Fabry-Perot. Measurements have been made with infrared laser light until 2004, and with green light during 2005. With a residual pressure less than 10-7 mbar the apparatus gives both ellipticity and rotation signals at the 10-7 rad level. These signals can be...

Observation of Significant Quantum Efficiency Enhancement from a Polarized Photocathode with Distributed Bragg Reflector

Energy Technology Data Exchange (ETDEWEB)

Zhang, Shukui [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Poelker, Matthew [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Stutzman, Marcy L. [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Chen, Yiqiao [SVT Associates, Inc., Eden Prairie, MN (United States); Moy, Aaron [SVT Associates, Inc., Eden Prairie, MN (United States)

2015-09-01

Polarized photocathodes with higher Quantum efficiency (QE) would help to reduce the technological challenge associated with producing polarized beams at milliampere levels, because less laser light would be required, which simplifies photocathode cooling requirements. And for a given amount of available laser power, higher QE would extend the photogun operating lifetime. The distributed Bragg reflector (DBR) concept was proposed to enhance the QE of strained-superlattice photocathodes by increasing the absorption of the incident photons using a Fabry-Perot cavity formed between the front surface of the photocathode and the substrate that includes a DBR, without compromising electron polarization. Here we present recent results showing QE enhancement of a GaAs/GaAsP strained-superlattice photocathode made with a DBR structure. Typically, a GaAs/GaAsP strained-superlattice photocathode without DBR provides a QE of 1%, at a laser wavelength corresponding to peak polarization. In comparison, the GaAs/GaAsP strained-superlattice photocathodes with DBR exhibited an enhancement of over 2 when the incident laser wavelength was tuned to meet the resonant condition for the Fabry-Perot resonator.

Photo-Induced Deformations of Liquid Crystal Elastomers

Science.gov (United States)

Dawson, Nathan; Kuzyk, Mark; Neal, Jeremy; Luchette, Paul; Palffy-Muhoray, Peter

2010-10-01

Over a century ago, Alexander Graham Bell transmitted mechanical information on a beam of light using the ``photophone.'' We report on the use of a Fabry-Perot interferometer to encode and detect mechanical information of an illuminated liquid crystal elastomer (LCE) that is placed at a critical point between the reflectors. Furthermore, we show that cascading of macroscopic LCE-interferometer devices is possible. These are the first steps in the creation of ultra smart materials. Such applications require materials with a large photomechanical response. Thus, understanding the underlying mechanisms is critical. Only limited studies of the mechanisms of photomechanical effects have been studied in azo-dye-doped LCEs. The focus of our present work is to use the Fabry-Perot transducer geometry to study the underlying mechanisms and to determine the relevant material parameters that are used to develop theoretical models of the response. We use various intensity-modulated optical wave forms to determine the frequency response of the material, which are used to predict the material response in the time domain.

Mechanisms of Photo-Induced Deformations of Liquid Crystal Elastomers

Science.gov (United States)

Dawson, Nathan; Kuzyk, Mark; Neal, Jeremy; Luchette, Paul; Palffy-Muhoray, Peter

2010-03-01

Over a century ago, Alexander Graham Bell invented the photophone, which he used to transmit mechanical information on a beam of light. We report on the use of an active Fabry-Perot interferometer to encode and detect mechanical information using the photomechanical effect of a liquid crystal elastomer (LCE) that is placed at a critical point between the reflectors. These are the first steps in the creation of ultra smart materials which require a large photomechanical response. Thus, understanding the underlying mechanisms is critical. Only limited studies of the mechanisms of the photomechanical effect, such as photo-isomerization, photo-reorientation and thermal effects have been studied in azo-dye-doped LCEs and in azo-dye-doped polymer fibers have been reported. The focus of our present work is to use the Fabry-Perot transducer geometry to study the underlying mechanisms and to determine the relevant material parameters that are used to develop theoretical models of the response. We use various intensity-modulated optical wave forms to determine the frequency response of the material, which are used to predict the material response.

Rapid electrostatics-assisted layer-by-layer assembly of near-infrared-active colloidal photonic crystals.

Science.gov (United States)

Askar, Khalid; Leo, Sin-Yen; Xu, Can; Liu, Danielle; Jiang, Peng

2016-11-15

Here we report a rapid and scalable bottom-up technique for layer-by-layer (LBL) assembling near-infrared-active colloidal photonic crystals consisting of large (⩾1μm) silica microspheres. By combining a new electrostatics-assisted colloidal transferring approach with spontaneous colloidal crystallization at an air/water interface, we have demonstrated that the crystal transfer speed of traditional Langmuir-Blodgett-based colloidal assembly technologies can be enhanced by nearly 2 orders of magnitude. Importantly, the crystalline quality of the resultant photonic crystals is not compromised by this rapid colloidal assembly approach. They exhibit thickness-dependent near-infrared stop bands and well-defined Fabry-Perot fringes in the specular transmission and reflection spectra, which match well with the theoretical calculations using a scalar-wave approximation model and Fabry-Perot analysis. This simple yet scalable bottom-up technology can significantly improve the throughput in assembling large-area, multilayer colloidal crystals, which are of great technological importance in a variety of optical and non-optical applications ranging from all-optical integrated circuits to tissue engineering. Copyright © 2016 Elsevier Inc. All rights reserved.

Isotope analysis of uranium by optical spectroscopy; Analyse isotopique de I'uranium par spectroscopie optique

Energy Technology Data Exchange (ETDEWEB)

Gerstenkorn, S [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1958-07-01

Isotope analysis of uranium is made by means of hollow cathode lamp and Fabry-Perot photoelectric spectrometer. When using the line U I 5027 A, this method allows to determine isotopic concentrations in {sup 235}U down to 0,1 per cent. The relative precision is about 2 per cent for amounts of {sup 235}U over 1 per cent. For weaker amounts this line would allow relative measurements of better precision when using standard mixtures. (author) [French] L'analyse isotopique de l'uranium est effectuee a l'aide d'une lampe a cathode creuse et du spectrometre Fabry-Perot photo-electrique. On utilise la raie U I 5027 A. Cette methode permet de doser des melanges isotopiques dont la teneur en {sup 235}U, peut descendre jusqu'a 0,1 pour cent. La precision relative est de l'ordre de 2 pour cent pour des teneurs en {sup 235}U superieures a 1 pour cent. Pour des teneurs plus faibles cette raie {lambda} = 5027 A permettrait des mesures relatives de meilleure precision, en utilisant des melanges prealablement doses. (auteur)