WorldWideScience

Sample records for civ vacuum-ultraviolet fabry-perot

  1. CIV Polarization Measurements Using a Vacuum Ultraviolet Fabry Perot

    Science.gov (United States)

    West, Edward A.

    2009-01-01

    Marshall Space Flight Center's (MSFC) is developing a Vacuum Ultraviolet (VUV) Fabry Perot that will be launched on a sounding rocket for high throughput, high-cadence, extended field of view CIV (155nm) measurements. These measurements will provide (i) Dopplergrams for studies of waves, oscillations, explosive events, and mass motions through the transition region, and, (ii), polarization measurements to study the magnetic field in the transition region. This paper will describe the scientific goals of the instrument, a brief description of the optics and the polarization characteristics of the VUV Fabry Perot.

  2. CIV Polarization Measurements using a Vacuum Ultraviolet Fabry-Perot Interferometer

    Science.gov (United States)

    West, Edward; Gary, G. Allen; Cirtain, Jonathan; David, John; Kobayashi, Ken; Pietraszewski, Chris

    2009-01-01

    Marshall Space Flight Center's (MSFC) is developing a Vacuum Ultraviolet (VUV) Fabry-P rot Interferometer that will be launched on a sounding rocket for high throughput, high-cadence, extended field of view CIV (155nm) measurements. These measurements will provide (i) Dopplergrams for studies of waves, oscillations, explosive events, and mass motions through the transition region, and, (ii), polarization measurements to study the magnetic field in the transition region. This paper will describe the scientific goals of the instrument, a brief description of the optics and the polarization characteristics of the VUV Fabry P rot.

  3. Fabry-Perot interferometry for microplasma diagnostics

    International Nuclear Information System (INIS)

    Hojo, H.; Mase, A.

    2006-01-01

    A new method for determining the electron density of a thin plasma by means of Fabry-Perot interferometry is proposed. The interferometer consists of two plasma layers and dielectric material surrounded by two plasma layers. The transmittance of electromagnetic waves across the interferometer is calculated, and Fabry-Perot resonances are demonstrated. It is shown that the electron density can be determined from the measurement of the Fabry-Perot resonance frequencies. This method can also be applied to the measurement of conduction electron density in semiconductor films

  4. Fourier Transform Fabry-Perot Interferometer

    Science.gov (United States)

    Snell, Hilary E.; Hays, Paul B.

    1992-01-01

    We are developing a compact, rugged, high-resolution remote sensing instrument with wide spectral scanning capabilities. This relatively new type of instrument, which we have chosen to call the Fourier-Transform Fabry-Perot Interferometer (FT-FPI), is accomplished by mechanically scanning the etalon plates of a Fabry-Perot interferometer (FPI) through a large optical distance while examining the concomitant signal with a Fourier-transform analysis technique similar to that employed by the Michelson interferometer. The FT-FPI will be used initially as a ground-based instrument to study near-infrared atmospheric absorption lines of trace gases using the techniques of solar absorption spectroscopy. Future plans include modifications to allow for measurements of trace gases in the stratosphere using spectral lines at terahertz frequencies.

  5. Fabry-Perot interferometry: astronomical applications

    International Nuclear Information System (INIS)

    Pismis, P.

    1982-01-01

    Some properties of the interference of light are presented with emphasis on interferometry by means of a Fabry-Perot etalon. The application of the etalon with a focal reducer to astronomical problems is discussed related in particular to the determination of radial velocities of extended emission objects, in galactic and extragalactic nebulae. Mention is also made of the work carried out in Mexico in this field as well as of developments under way. (author)

  6. Internal scattering in Fabry-Perot cavities

    International Nuclear Information System (INIS)

    Cadez, A.

    1990-01-01

    Interferometers are the most promising sensors for large gravity-wave detectors. The coupling of the enclosure noise to the gravity-wave signal in a Fabry-Perot interferometer is studied. The first part provides a theoretical framework, and in the second part two-limiting cases are discussed as an illustration. The relevance of this noise source for large gravity-wave interferometers is briefly discussed in the Conclusion

  7. An Archetype Semi-Ring Fabry-Perot (SRFP) Resonator

    Science.gov (United States)

    Taghavi-Larigani, Shervin; VanZyl, Jakob

    2009-01-01

    We introduce and demonstrate the generation of a novel resonator, termed Semi-Ring Fabry-Perot (SRFP), that exhibits unique features, such as, its use of one plane mirror, allowing the SRFP to be easily fabricated as a symmetrical device. In addition to its unique features, it exhibits advantages of ring and Fabry-Perot resonators: 1) compared to a ring resonator that only allows a transmitted intensity, the Semi-Ring Fabry-Perot (SRFP) supports standing waves, allowing both a reflected and transmitted intensity; 2) the reflected light spectrum of the SRFP resonator is much narrower than similar Fabry-Perot, implying higher finesse.

  8. Dynamic resonance of light in Fabry-Perot cavities

    International Nuclear Information System (INIS)

    Rakhmanov, M.; Savage, R.L.; Reitze, D.H.; Tanner, D.B.

    2002-01-01

    The dynamics of light in Fabry-Perot cavities with varying length and input laser frequency are analyzed. At high frequencies, the response to length variations is very different from the response to laser frequency variations. Implications for kilometer-scale Fabry-Perot cavities such as those utilized in gravitational-wave detectors are discussed

  9. Far infrared metal mesh filters and Fabry-Perot interferometry

    International Nuclear Information System (INIS)

    Kiyomi, S.; Genzel, L.

    1983-01-01

    The use of metal meshes is becoming increasingly important for applications in the far infrared. This paper reviews the important aspects of metal meshes, metal mesh filters, Fabry-Perot interferometers and their applications. The article includes the following: an introductory description and historical review of far-infrared metal meshes, the optical properties of metal meshes, beam splitters and filters based on inherent optical properties of meshes, Fabry-Perot interferometers, multimesh filters, applications of metal mesh filters and Fabry-Perot interferometers for far-infrared lasers, for plasma diagnostics and for astronomy

  10. Plasmonic flat surface Fabry-Perot interferometry

    Science.gov (United States)

    Sain, Basudeb; Kaner, Roy; Bondy, Yaara; Prior, Yehiam

    2018-02-01

    We report measurements of the optical transmission through a plasmonic flat surface interferometer. The transmission spectrum shows Fabry-Perot-like modes, where for each mode order, the maximal transmission occurs at a gap that grows linearly with wavelength, giving the appearance of diagonal dependence on gap and wavelength. The experimental results are supported by numerical solutions of the wave equations and by a simplified theoretical model that is based on the coupling between localized and propagating surface plasmon. This work explains not only the appearance of the modes but also their sharp dependence on the gap, taking into consideration the refractive indices of the surrounding media. The transmission spectra provide information about the phase difference between the light impinging on the two cavities, enabling interferometric measurement of the light phase by transmission through the coupled plasmonic cavities. The 1° phase-difference resolution is obtained without any propagation distance, thus making this interferometer suitable for on-chip operation.

  11. Nonlinear Fabry-Perot filled with CS2 and nitrobenzene

    International Nuclear Information System (INIS)

    Bischofberger, T.; Shen, Y.R.

    1979-01-01

    We have studied the characteristics of nonlinear Fabry-Perot filled with Kerr liquids CS 2 and nitorbenzene and found excellent agreement between theory and experiment. The transient behavior due to cavity-field buildup is discussed

  12. Micromachined Fabry-Perot Interferometer for Motion Detection

    National Research Council Canada - National Science Library

    Waters, Richard L; Aklufi, Monti E

    2002-01-01

    The monolithic integration of a Fabry-Perot interferometer and a (100) silicon photodiode is reported for use as a highly sensitive transduction method in the detection of minute displacements of a proof mass attached to a spring...

  13. Plasmonic flat surface Fabry-Perot interferometry

    Directory of Open Access Journals (Sweden)

    Sain Basudeb

    2018-02-01

    Full Text Available We report measurements of the optical transmission through a plasmonic flat surface interferometer. The transmission spectrum shows Fabry-Perot-like modes, where for each mode order, the maximal transmission occurs at a gap that grows linearly with wavelength, giving the appearance of diagonal dependence on gap and wavelength. The experimental results are supported by numerical solutions of the wave equations and by a simplified theoretical model that is based on the coupling between localized and propagating surface plasmon. This work explains not only the appearance of the modes but also their sharp dependence on the gap, taking into consideration the refractive indices of the surrounding media. The transmission spectra provide information about the phase difference between the light impinging on the two cavities, enabling interferometric measurement of the light phase by transmission through the coupled plasmonic cavities. The 1° phase-difference resolution is obtained without any propagation distance, thus making this interferometer suitable for on-chip operation.

  14. Polarisation dynamics of a birefringent Fabry-Perot cavity

    Science.gov (United States)

    Ejlli, A.; Della Valle, F.; Zavattini, G.

    2018-02-01

    Optical Fabry-Perot cavities always show a non-degeneracy of two orthogonal polarisation states. This is due to the unavoidable birefringence of dielectric mirrors whose effects are extremely important in Fabry-Perot-based high-accuracy polarimeters: in birefringent cavities, ellipticities and rotations mix. We have developed and present here a theory of the polarisation state dynamics in a birefringent Fabry-Perot resonator, and we validate it through measurements performed with the polarimeter of the PVLAS experiment. The measurements are performed while a laser is frequency-locked to the cavity, and provide values for the phase difference between the two orthogonal polarisation components introduced by the combination of the two cavity mirrors (equivalent wave-plate) and for the finesse of the cavity. The theoretical formulas and the experimental data agree well showing that the consequences of the mirror birefringence must be taken into account in this and in any other similar experiment.

  15. Test of an intensity-compensated Fabry-Perot interferometer

    International Nuclear Information System (INIS)

    Kamiyama, Hiroshi; Okano, Shoichi

    1977-01-01

    In measurement of the heating effect when high-energy charged particles fall into the ultra-high atmosphere, the Doppler width of auroral bright lines was measured with a Fabry-Perot interferometer. To overcome the difficulty in directly measuring auroral temperature with a Fabry-Perot interferometer, in the intensity-compensated type, the quantity aF/I is recorded: I the intensity of small part of the light entering the interferometer, F the detected output, and a constant. The width of the bright lines can be obtained with high accuracy. (Mori, K.)

  16. Nanometer measurement with a dual Fabry-Perot interferometer

    International Nuclear Information System (INIS)

    Chen Benyong; Li Dacheng; Guo Songling; Zhu Ruogu; Wu Zhaotong

    2001-01-01

    On the basis of analyzing sinusoidal phase-modulating Fabry-Perot interferometry, a method, believed to be novel, is proposed for achieving nanometer measurement accuracy by measuring the time interval between equal amplitudes of the two elementary frequency signals of the transmitted intensities of a dual Fabry-Perot interferometer. A nanometer measurement system based on the method was designed and tested. The experimental results show that the displacement resolution of the system is 0.32 nm at a 1-kHz modulating signal

  17. On-chip optical filter comprising Fabri-Perot resonator structure and spectrometer

    Energy Technology Data Exchange (ETDEWEB)

    Han, Seunghoon; Horie, Yu; Faraon, Andrei; Arbabi, Amir

    2018-04-10

    An on-chip optical filter having Fabri-Perot resonators and a spectrometer may include a first sub-wavelength grating (SWG) reflecting layer and a second SWG reflecting layer facing each other. A plurality of Fabri-Perot resonators are formed by the first SWG reflecting layer and the second SWG reflecting layer facing each other. Each of the Fabri-Perot resonators may transmit light corresponding to a resonance wavelength of the Fabri-Perot resonator. The resonance wavelengths of the Fabri-Perot resonators may be determined according to duty cycles of grating patterns.

  18. New Fabry-Perot interferometer system for infrared astronomy

    International Nuclear Information System (INIS)

    Herbst, T.M.; Beckwith, S.

    1988-01-01

    A new NIR Fabry-Perot spectrometer system is described. The instrument uses a commercial-etalon in combination with a cooled grating spectrometer to achieve wavelength resolutions of 1000-100,000 in the 2-5-micron wavelength region. A custom housing supplies mechanical support, rigidity, versatility in optical layout, and laboratory wavelength references for several astrophysically important transitions

  19. 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.)

  20. Development of the Fabry-Perot Spectrometer Application

    Science.gov (United States)

    Browne, Kathryn

    2015-01-01

    Methane is a greenhouse gas with global warming effects 20 times more detrimental than carbon dioxide. Currently, only aircraft missions measure methane and do not provide continuous monitoring, This presentation will cover the Fabry-Perot spectrometer which will provide continuous monitoring of methane. It will also cover the development of the software used to extract and process the data the spectrometer collects.

  1. Silicon Carbide Mounts for Fabry-Perot Interferometers

    Science.gov (United States)

    Lindemann, Scott

    2011-01-01

    Etalon mounts for tunable Fabry- Perot interferometers can now be fabricated from reaction-bonded silicon carbide structural components. These mounts are rigid, lightweight, and thermally stable. The fabrication of these mounts involves the exploitation of post-casting capabilities that (1) enable creation of monolithic structures having reduced (in comparison with prior such structures) degrees of material inhomogeneity and (2) reduce the need for fastening hardware and accommodations. Such silicon carbide mounts could be used to make lightweight Fabry-Perot interferometers or could be modified for use as general lightweight optical mounts. Heretofore, tunable Fabry-Perot interferometer structures, including mounting hardware, have been made from the low-thermal-expansion material Invar (a nickel/iron alloy) in order to obtain the thermal stability required for spectroscopic applications for which such interferometers are typically designed. However, the high mass density of Invar structures is disadvantageous in applications in which there are requirements to minimize mass. Silicon carbide etalon mounts have been incorporated into a tunable Fabry-Perot interferometer of a prior design that originally called for Invar structural components. The strength, thermal stability, and survivability of the interferometer as thus modified are similar to those of the interferometer as originally designed, but the mass of the modified interferometer is significantly less than the mass of the original version.

  2. Fabry-Perot interferometer utilized for displacement measurement in a large measuring range

    International Nuclear Information System (INIS)

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

    2010-01-01

    The optical configuration of a Fabry-Perot interferometer is uncomplicated. This has already been applied in different measurement systems. For the displacement measurement with the Fabry-Perot interferometer, the result is significantly influenced by the tilt angles of the measurement mirror in the interferometer. Hence, only for the rather small measuring range, the Fabry-Perot interferometer is available. The goal of this investigation is to enhance the measuring range of Fabry-Perot interferometer by compensating the tilt angles. To verify the measuring characteristic of the self-developed Fabry-Perot interferometer, some comparison measurements with a reference standard have been performed. The maximum deviation of comparison experiments is less than 0.3 μm in the traveling range of 30 mm. The experimental results show that the Fabry-Perot interferometer is highly stable, insensitive to environment effects, and can meet the measuring requirement of the submicrometer order.

  3. Levitated optomechanics with a fiber Fabry-Perot interferometer

    Science.gov (United States)

    Pontin, A.; Mourounas, L. S.; Geraci, A. A.; Barker, P. F.

    2018-02-01

    In recent years, quantum phenomena have been experimentally demonstrated on variety of optomechanical systems ranging from micro-oscillators to photonic crystals. Since single photon couplings are quite small, most experimental approaches rely on the realization of high finesse Fabry-Perot cavities in order to enhance the effective coupling. Here we show that by exploiting a, long path, low finesse fiber Fabry-Perot interferometer ground state cooling can be achieved. We model a 100 m long cavity with a finesse of 10 and analyze the impact of additional noise sources arising from the fiber. As a mechanical oscillator we consider a levitated microdisk but the same approach could be applied to other optomechanical systems.

  4. Fast-scanning far-infrared Fabry--Perot interferometer

    International Nuclear Information System (INIS)

    Komm, D.S.; Blanken, R.A.; Brossier, P.

    1975-01-01

    A scanning Fabry--Perot interferometer for use in the far ir (100 μ m less than lambda less than 2 mm) has been developed capable of scanning a free spectral range in a few milliseconds. A commercial loudspeaker was used as a drive, and mirrors were fabricated from electroformed copper mesh. Primary limitations of the instrument were due to vibrations of the interferometer frame. (U.S.)

  5. Gamma irradiation of Fabry-Perot interband cascade lasers

    Science.gov (United States)

    Myers, Tanya L.; Cannon, Bret D.; Brauer, Carolyn S.; Canedy, Chadwick L.; Kim, Chul Soo; Kim, Mijin; Merritt, Charles D.; Bewley, William W.; Vurgaftman, Igor; Meyer, Jerry R.

    2018-01-01

    The effects of gamma radiation on Fabry-Perot interband cascade lasers (ICLs) were investigated. Two ICLs were exposed to cobalt-60 gamma rays for a total dose of 500 krad(Si) each. The ICLs do not show any evidence of changes in performance, including output power, threshold current, slope efficiency, or spectral frequency. These results demonstrate that ICLs are insensitive to gamma irradiation up to exposure rates above those normally encountered within a shielded spacecraft.

  6. A new method of electron density measurement by Fabry-Perot interferometry

    International Nuclear Information System (INIS)

    Hojo, Hitoshi; Mase, Atsushi

    2004-01-01

    A new method for determining the electron density of a thin plasma by means of Fabry-Perot interferometry is proposed. The interferometer consists of two plasma layers and dielectric material surrounded by two plasma layers. The transmittance of electromagnetic waves across the interferometer is calculated, and Fabry-Perot resonances are frequency when the width of a plasma layer is known. (author)

  7. Instabilities for a coherently driven absorber in a Fabry-Perot cavity

    International Nuclear Information System (INIS)

    Casagrande, F.; Lugiato, L.A.; Asquini, M.L.

    1980-01-01

    We consider a suitable set of equations of the electric field with a system of N two-level atoms contained in a Fabry-Perot and driven by a cw laser beam (optical bistability). The stability of the stationary solutions is analyzed. Instabilities of the self-pulsing, a ring cavity is more suitable than a Fabry-Perot. (orig.)

  8. Fabry-Perot spectrometer for high resolution light scattering investigations

    International Nuclear Information System (INIS)

    Deniz, K.U.; Parvathanathan, P.S.; Paranjpe, A.S.

    1976-01-01

    A Fabry-Perot spectrometer designed specially for carrying out Brillouin scattering experiment is described in detail. The instrument has free spectral range in the domain of frequencies 1 - 10 GHz and resolution widths in the range of 30 MHz - 3 GHz. The signal to noise ratio has been improved by a factor of about 10 3 by : (1) cooling the photomultiplier detector and (2) the use of magnetic defocussing techniques. With the use of a single frequency laser source, accurate determination of Brillouin frequency shifts and of Brillouin line shapes can be made with this spectrometer. Some preliminary results obtained with a few simple liquids, are discussed. (author)

  9. Intrinsic Fabry-Perot Sensors for Magnetic Field Detection

    Science.gov (United States)

    Broadway, Christian; Descamps, Frédéric; Kinet, Damien; Caucheteur, Christophe; Mégret, Patrice

    2018-01-01

    Within the context of ensuring stable nuclear fusion, it is important to monitor and control a number of parametersincluding the magnetic field associated with plasma circulation. Optical fibre sensing techniques have seen a surge in promulgation and research advances in recent years, due to their immunity to electromagnetic radiation and compact dimensions. Prior work has shown that fibre Bragg gratings are one method of recovering the induced magnetic field, with the main point of interest being their use as distributed point sensors. However, Bragg grating inscription leads to the creation of linear birefringence that increases detector noise and could obscure a given signal. We have hypothesised that by using an intrinsic Fabry-Perot cavity comprised of two identical Bragg gratings, we could obtain a more accurate detector with the removal of photo-induced birefringence in the detection region. We present a proof of concept optical fibre sensor based on an intrinsic Fabry-Perot cavity that shows spectrally visible amplitude modulation. Finally, we demonstrate faster data processing that allows real time monitoring of a given scenario.

  10. Fabry-Perot Diaphragm Fiber Optic Sensor (DFOS for Acoustic Detection

    Directory of Open Access Journals (Sweden)

    Yan SUN

    2007-10-01

    Full Text Available A diaphragm fiber optic sensor (DFOS solely based on Fabry-Perot multiple beam interference has been designed and fabricated with micro-electric mechanical system (MEMS technology. The silicon diaphragm with an embossed center was designed with an interference gap width kept accurately. The DFOS was verified to be a truly and purely Fabry-Perot device via a critical test. Parallel testing with a Piezoelectric (PZT sensor showed that the DFOS had high sensitivity. The Fabry-Perot DFOS also demonstrated excellent performance in on-line monitoring of Partial Discharge (PD in power transformers.

  11. Millimeter-long fiber Fabry-Perot cavities.

    Science.gov (United States)

    Ott, Konstantin; Garcia, Sebastien; Kohlhaas, Ralf; Schüppert, Klemens; Rosenbusch, Peter; Long, Romain; Reichel, Jakob

    2016-05-02

    We demonstrate fiber Fabry-Perot (FFP) cavities with concave mirrors that can be operated at cavity lengths as large as 1.5 mm without significant deterioration of the finesse. This is achieved by using a laser dot machining technique to shape spherical mirrors with ultralow roughness and employing single-mode fibers with large mode area for good mode matching to the cavity. Additionally, in contrast to previous FFPs, these cavities can be used over an octave-spanning frequency range with adequate coatings. We also show directly that shape deviations caused by the fiber's index profile lead to a finesse decrease as observed in earlier attempts to build long FFP cavities, and show a way to overcome this problem.

  12. 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

  13. Compact High-Resolution Broad-Band Terahertz Fabry-Perot Spectrometer, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Our objective is to develop a compact scanning Fabry-Perot spectrometer, for satellite far-infrared astronomy and Earth remote sensing, that operates at wavelengths...

  14. Fabry-Perot Based Ranging Interferometer Receiver for High Spectral Resolution Lidar, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — Michigan Aerospace Corporation (MAC) is pleased to present the following Phase II proposal for a Fabry-Perot Based Interferometer Receiver for the High Spectral...

  15. Rugged Low Temperature Actuators for Tunable Fabry Perot Optical Filters, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — During our Phase I SBIR research, we propose to integrate a novel low-temperature large-strain actuator technology into Fabry-Perot optical filters. The resulting...

  16. 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

  17. Far-infrared applications of high-temperature superconductors: Fabry-Perot resonators and fast detectors

    International Nuclear Information System (INIS)

    Renk, K.F.

    1993-01-01

    Far-infrared applications of high temperature superconductors, namely Fabry-Perot resonators and fast detectors, are reported. At terahertz frequencies high finesse (∝60 at 3 THz) is obtained for Fabry-Perot resonators with YBa 2 Cu 3 O 7 -on-MgO reflectors and fast, nonbolometric response with a response time 2 Cu 3 O 7 thin films at frequencies from 0.1 THz to nearly 10 THz. (orig.)

  18. Engineering-reflected phase in Fabry-Perot sensors with resonant mirrors.

    Science.gov (United States)

    Gellineau, Antonio; Wong, Yu-Po; Solgaard, Olav

    2013-12-01

    Fabry-Perot cavities made with photonic crystal (PC) mirrors and other resonant structures exhibit nontraditional characteristics due to the strong wavelength dependence of their reflected phase. This Letter describes how engineering the phase of PC mirrors enables sensors that are tolerant to variations in laser center frequency and line width. Reflection spectra measurements of Fabry-Perot cavities made with PC mirrors were collected as a function of wavelength and cavity length, providing experimental verification of theory and simulations.

  19. Influence of intensity loss in the cavity of a folded Fabry-Perot interferometer on interferometric signals

    International Nuclear Information System (INIS)

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

    2011-01-01

    Fabry-Perot interferometer is often used for the micro-displacement, because of its common optical path structure being insensitive to the environmental disturbances. Recently, the folded Fabry-Perot interferometer has been investigated for displacement measurements in large ranges. The advantages of a folded Fabry-Perot interferometer are insensitive to the tilt angle and higher optical resolution. But the design of the optical cavity has become more and more complicated. For this reason, the intensity loss in the cavity will be an important parameter for the distribution of the interferometric intensity. To obtain a more accurate result of such interferometer utilized for displacement measurements, the intensity loss of the cavity in the fabricated folded Fabry-Perot interferometer and the modified equation of the folded Fabry-Perot interferometer will be described. According to the theoretical and experimental results, the presented model is available for the analysis of displacement measurements by a folded Fabry-Perot interferometer.

  20. Optical fiber Fabry-Perot interferometer for microorganism growth detection

    Science.gov (United States)

    Liu, Xiaohui; Jiang, Mingshun; Sui, Qingmei; Luo, Shuyang; Geng, Xiangyi

    2016-07-01

    An optical fiber Fabry-Perot interferometer (FPI) based on hollow-core photonic crystal fiber (HCPCF) for microorganism growth detection is proposed and demonstrated. The FPI is formed by splicing both ends of a short section of HCPCF to SMFs and cleaving the SMF pigtail to a proper length. By measuring the fringe contrast of interference pattern, the refractive index (RI) changes of analyte during microorganism growth can be obtained. RI response of the sensor was investigated theoretically and experimentally. It shows linear response with sensitivity of -136 dB/RIU and good repeatability. Temperature response was also tested and the result confirms the low temperature cross-sensitivity of the sensor. Detection of yeast growth in liquid medium by the FPI sensor was conducted and the result shows the characteristic of typical yeast growth curve. With its advantages of high RI sensitivity, low temperature cross-sensitivity, capability for real-time measurement and so on, this FPI sensor has great potential in biosensing.

  1. Fabry-Perot Interferometer for Column CO2: Airborne

    Science.gov (United States)

    Kawa, S. R.; Heaps, W. S.; Mao, J.; Andrews, A. E.; Burris, J. F.; Miodek, M.; Georgieva, E.

    2002-01-01

    Global atmospheric CO2 measurements are essential to resolving significant discrepancies in our understanding of the global carbon budget and, hence, humankind's role in global climate change. The science measurement requirements for CO2 are, however, extremely demanding (precision approximately 0.3%). We are developing a novel application of a Fabry-Perot interferometer to detect spectral absorption of reflected sunlight by CO2 and O2 in the atmosphere that should be able to achieve sufficient sensitivity and signal-to-noise to measure column CO2 at the target specification. We are currently constructing a prototype instrument for deployment on aircraft. The aircraft version will measure total column CO2 and CO2 below the aircraft as well as O2, which allows normalization of CO2 column amounts for varying surface height and pressure. This instrument will be a valuable asset in carbon budget field studies as well as a useful tool for evaluating existing and future space-based CO2 measurements. We will present the instrument concept, sensitivity calculations, and the results of testing a bench system in the laboratory and outdoors on the ground. We will also discuss our plan for deployment on the aircraft and potential flight applications to the CO2 budget problem.

  2. Fabry-Perot Interferometer for Column CO2

    Science.gov (United States)

    Heaps, William S.; Kawa, Randolph; Bhartia, P. K. (Technical Monitor)

    2002-01-01

    Global atmospheric CO2 measurements are essential to resolving significant discrepancies in our understanding of the global carbon budget and, hence, humankind's role in global climate change. The science measurement requirements for CO2 are extremely demanding (precision approx. 0.3%). No atmospheric chemical species has ever been measured from space with this precision. We are developing a novel application of a Fabry-Perot interferometer to detect spectral absorption of reflected sunlight by CO2 and O2 in the atmosphere. Preliminary design studies indicate that the method will be able to achieve the sensitivity and signal-to-noise detection required to measure column CO2 at the target specification. The objective of this program is to construct a prototype instrument for deployment on an aircraft to test the instrument performance and our ability to retrieve the data in the real atmosphere. To date we have assembled a laboratory bench system to begin testing the optical and electronic components. We are also measuring signal and noise levels in actual sunlight to evaluate component performance.

  3. Optical fiber Fabry-Perot sensors for smart structures

    Science.gov (United States)

    Lee, C. E.; Alcoz, J. J.; Yeh, Y.; Gibler, W. N.; Atkins, R. A.; Taylor, H. F.

    1992-06-01

    The paper describes the operation principles and the construction, performance, and application of optical fiber Fabry-Perot interferometers (FFPIs) utilizing internal mirrors, developed for sensing temperature, strain, acoustic waves, and other physical perturbations in structural materials. It is shown that the internal-mirror FFPI sensors have a good mechanical strength which make it possible for the sensors to endure mechanical stresses experienced during the embedding process, and provide high sensitivity and point-sensing and ultrasound pressure. A digital signal processor is described. the 29th International Conference on the Applications of the Mössbauer Effect (ICAME 2007) held in Kanpur, India, 14-19 October 2007, PART IV/VII 30 2008 11 19 2008 11 18 2008 7 2008 Springer Science+Business Media B.V. 2008 9819 10.1007/s10751-008-9819-1 17 57Fe-Mössbauer study of electrically conducting barium iron vanadate glass after heat treatment 115 121 2008 9 17 2008 10 9 Spr

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

    Energy Technology Data Exchange (ETDEWEB)

    Meng Qinghua [College of Physics and Electronic Engineering, Guangxi Teachers Education University, Nanning, 530023 (China); Luo Huan; Bao Shiwei; Zhou Yifan; Chen Sihai, E-mail: mqhgx@163.com [College of Optoelectronic Science and Engineering, Huazhong University of Science and Technology, Wuhan, 430074 (China)

    2011-02-01

    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.

  5. Rayleigh Scattering Measurements Using a Tunable Liquid Crystal Fabry-Perot Interferometer

    Science.gov (United States)

    Mielke-Fagan, Amy F.; Clem, Michelle M.; Elam, Kristie A.

    2010-01-01

    Spectroscopic Rayleigh scattering is an established flow diagnostic that has the ability to provide simultaneous density, velocity, and temperature measurements. The Fabry-Perot interferometer or etalon is a commonly employed instrument for resolving the spectrum of molecular Rayleigh scattered light for the purpose of evaluating these flow properties. This paper investigates the use of a tunable liquid crystal (LC) Fabry-Perot etalon in Rayleigh scattering experiments at NASA Glenn Research Center. The LC etalon provides a robust interferometry system that can be tuned rapidly by adjusting the voltage applied to the liquid crystal interface. Tuning the interferometer is often necessary to control the physical locations of the concentric interference fringes when Rayleigh light is imaged through the LC etalon. The LC etalon diagnostic system was tested in a 1-cm diameter nozzle flow in two different scattering configurations to evaluate its usefulness for Rayleigh measurements compared to a traditional non-tunable fused silica Fabry-Perot etalon.

  6. 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.

  7. Wide field of view spectroscopy using Fabry-Perot Interferometers

    Science.gov (United States)

    Nikoleyczik, Jonathan

    We present a high resolution spectrometer consisting of dual solid Fabry-Perot Interferometers (FPIs). This work is intended to be an all inclusive documentation of the instrument including discussion of the design of this instrument, the methods used in data reduction, and the analysis of these data. Each FPI is made of a single piece of L-BBH2 glass which has a high index of refraction n 2.07 with a thickness on the order of 100 mum. Each is then coated with partially reflective mirrors to create a resonant cavity and thus achieve a spectral resolution of R 30,000. Running the FPIs in tandem reduces the overlapping orders and allows for a much wider free spectral range and higher contrast. We will also discuss the properties of the FPIs which we have measured. This includes the tuning of the FPIs which is achieved by adjusting the temperature and thus changing the FPI gap and the refractive index of the material. The spectrometer then moves spatially in order to get spectral information at every point in the field of view. We select spectral lines for further analysis and create maps of the line depths across the field. Using this technique we are able to measure the fluorescence of chlorophyll in plants and attempt to observe zodiacal light. In the chlorophyll analysis we are able to detect chlorophyll fluorescence using the line depth in a plant using the sky as a reference solar spectrum. This instrument has possible applications in either a cubesat or aerial observations to measure bulk plant activity over large areas.

  8. High-temperature fiber-optic Fabry-Perot interferometric sensors

    International Nuclear Information System (INIS)

    Ding, Wenhui; Jiang, Yi; Gao, Ran; Liu, Yuewu

    2015-01-01

    A photonic crystal fiber (PCF) based high-temperature fiber-optic sensor is proposed and experimentally demonstrated. The sensor head is a Fabry-Perot cavity manufactured with a short section of endless single-mode photonic crystal fiber (ESM PCF). The interferometric spectrum of the Fabry-Perot interferometer is collected by a charge coupled device linear array based micro spectrometer. A high-resolution demodulation algorithm is used to interrogate the peak wavelengths. Experimental results show that the temperature range of 1200 °C and the temperature resolution of 1 °C are achieved

  9. High-temperature Fabry-Perot-based strain sensor for ceramic barrier filters

    Science.gov (United States)

    Weinstein, Shmuel J.; Vuppala, Veerendra B.; Gunther, Michael F.; Wang, Anbo; Murphy, Kent A.; Claus, Richard O.

    1994-02-01

    We report results from a program to develop fiber-optic sensor-based instrumentation methods to allow the in-situ analysis of ceramic barrier filters. The sensor used was an extrinsic Fabry-Perot cavity created between the ends of two longitudinally aligned fibers. Filters instrumented with these fiber sensors were tested in a combustor simulator at the Westinghouse Science and Technology Center. These tests were performed using silica optical fibers capable of withstanding the high temperature and harsh chemical environment of the combustor. The single-ended approach of the reflective Fabry-Perot sensors is well suited for high thermal strain measurements. The results from several tests are presented.

  10. 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.

  11. Fabry-Perot micro-structured polymer optical fibre sensors for opto-acoustic endoscopy

    DEFF Research Database (Denmark)

    Broadway, Christian; Gallego, Daniel; Woyessa, Getinet

    2015-01-01

    Opto-Acoustic Endoscopy (OAE) requires sensors with a high sensitivity and small physical dimensions in order to facilitate integration into an endoscope of less than 1mm in diameter. We present fibre Bragg grating (FBG) and Fabry- Perot intrinsic fibre sensors for ultrasound detection. We present...

  12. A Ray-tracing Method to Analyzing Modulated Planar Fabry-Perot Antennas

    DEFF Research Database (Denmark)

    Hougs, Mikkel Dahl; Kim, Oleksiy S.; Breinbjerg, Olav

    2015-01-01

    A new approach for fast modelling of Fabry-Perot antennas with modulated partially reflective surfaces (PRS) using ray-tracing is proposed. For validation of the method, a configuration is introduced which consists of a cavity with a modulated PRS, fed internally by a magnetic dipole. The PRS...

  13. 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...

  14. Building and testing a Fabry-Perot interferometer for measuring narrow linewidth lasers

    International Nuclear Information System (INIS)

    Mani, A. A.

    2008-01-01

    This report describe the realization of a Fabry-Perot interferometer dedicated for measuring laser spectral resolutions better than 0.04 cm-1 in the visible spectral range. This instrument is employed for spectral characterization of the laboratory-build due lasers.(author)

  15. 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...

  16. Fabry-perot for airborne infrared astronomy and the [Si II] emission from the galactic center

    International Nuclear Information System (INIS)

    Graf, P.H.

    1988-01-01

    A Fabry-Perot spectrometer for infrared astronomy was built for and used on NASA's Kuiper Airborne Observatory. This instrument produces very high resolution spectra between 15 and 50 μm. The Fabry-Perot uses free-standing metal mesh for its optical resonant cavity and servo-controlled motors to vary the transmitted wavelengths. The fine-structure lines of [S III] to 18.71 μm (M42) and 33.482 μm (M17) in Galactic HII regions and [Si II] at 34.816 μm (S 106) in a photodissociation region (PDR) were observed with the Fabry-Perot. The distribution of the [Si II] 34.816-μm emission from within 5 parsecs of the Galactic center is measured with the Cornell high-resolution grating spectrometer, which is also used as the order-sorter for the Fabry-Perot. The gas-phase abundance of silicon within the neutral gas ring surrounding the Galactic center is 4.5 x 10 -6 . The Si II 34.8-μm/O I 63.2-μm line ratio is independent of the emitting region temperature and density, so the relative abundance of Si II to O I may be determined directly

  17. Remote Characterization of Chemical Vapor Plumes by LWIR Imaging Fabry-Perot Spectrometry

    National Research Council Canada - National Science Library

    Gittins, Christopher M; Marinelli, William J; Jensen, James O

    2001-01-01

    Physical Sciences Inc. has developed and tested two long-wavelength infrared (LWIR) hyperspectral imaging spectroradiometers based on the insertion of a rapidly tunable Fabry-Perot etalon in the field of view of a HgCdTe focal plane array...

  18. High precision planar waveguide propagation loss measurement technique using a Fabry-Perot cavity

    DEFF Research Database (Denmark)

    Feuchter, Thomas; Thirstrup, Carsten

    1994-01-01

    A high precision measurement technique for characterizing the propagation loss in silica low-loss optical waveguides, based on measuring the contrast of a Fabry-Perot cavity, is demonstrated. The cavity consists of the waveguide coupled to two polarization-maintaining fibers, each end facet coated...

  19. 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

  20. Study on the embedment of fiber Fabry-Perot strain sensor in prestressed reinforced concrete bridges

    Science.gov (United States)

    Chen, WeiMin; Zhu, Yong; Fu, YuMei; Huang, Shanglian

    2004-07-01

    In order to address application problem of fiber optic sensor in concrete, characteristics of concrete was analyzed deeply. Mechanical and metrological characteristics of both bare and packed fiber Fabry-Perot strain sensor were also analyzed in details. Modulus requirement and dimensional requirement of fiber strain sensor for concrete was deduced. A special measure of sleeve was proposed to get rid of drawback of packed fiber Fabry-Perot strain sensor in concrete. Corresponding procedures was also proposed to ensure survivability of the sensors when embedding fiber sensor into a concrete structure. An application example of fiber Fabry-Perot strain sensor network system in the Dafosi Bridge of Yangtze River at Chongqing has been presented to demonstrate the validity of this technique. With help of presented technique, 45 fiber Fabry-Perot strain sensors had been successfully embedded in 5 segments of gird during 9 months construction. The system was put into operation automatically from January 2003. Some typical results recorded by the system were presented. Constructing progress, tardo distortion trend, and temperature dependent fluctuation of gird was revealed in the result.

  1. 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.

  2. Studies on the construction of a Fabry-Perot interferometer for Moessbauer radiation

    International Nuclear Information System (INIS)

    Lerche, M.

    2004-08-01

    The work presented here consists basically of two parts, which provide the basement for the construction of a combined Fabry-Perot interferometer for visible light and for the Moessbauer radiation of 57 Fe. Such instruments could be used in the field of metrology to bridge the gap between visible light and X-rays. The main components a of Fabry-Perot interferometer are two mirrors, aligned parallel and separated by a gap. For the realization of the desired mirrors for the Moessbauer radiation, the (1 3 anti 4 28)-reflex in sapphire (α-Al 2 O 3 ) can be used. However, at the position of exact backscattering this reflex is accompanied by two additional beams. Together with the transmitted beam this particular case is a four-beam case. Bragg reflections accompanying a back-reflection are excited always in pairs. As a result, the four-beam case is the simplest multiple-beam Bragg diffraction case with one reflection in backscattering. This special case is treated both, experimentally and theoretically in the first part of this thesis. The waves excited additionally reduce the reflectivity into the desired backscattering channel. In order to use the (1 3 anti 4 28)-reflex for the mirrors of an X-ray Fabry-Perot interferometer for Moessbauer radiation, it is essential to understand how the occurrence of the additional beams may be suppressed. Furthermore, it is of fundamental scientific interest to study this multiple-beam case with the minimum number of diffracted waves. To bridge the (metrological) gap between visible light and X-rays, the wavelength of the 57 Fe Moessbauer radiation shall be connected to the well known wavelength of an iodine-stabilized He-Ne laser. For this purpose the gap-width between the mirrors of the combined Fabry-Perot interferometer must be variable. An additional issue is, that the reflecting atomic planes of the X-ray mirrors must be parallel within some nrad. This parallelism can only be reached by building the whole Fabry-Perot

  3. Single cavity Fabry-Perot modulator enhancements and integrated vertically coupled cavity light-emitting diode

    Science.gov (United States)

    Liu, Daxin

    Fabry-Perot modulators with Multi-Quantum Wells (MQWs) cavities have been studied with great interest during recent years. Usually operating as intensity modulators, these devices have very high modulation contrast ratios, can be operated at very high speed, can be easily made into two dimensional arrays and can be integrated with silicon ICs. They are thus very promising for optical interconnects, optical switching and image processing applications. But before these modulators are to be used in real applications, there are several issues that need to be solved, including the parasitic phase modulation, the bandwidth of such modulators and the alignment of modulator operation wavelength with the wavelength of lasers or light emitting diodes. In this work, the phase properties of Fabry-Perot reflection modulators will be discussed first and an experimental method using a modified Michelson interferometer to characterize the exact phase change will be demonstrated. It is demonstrated that the phase of the reflection light beam from a Fabry-Perot modulator is determined not only by the refractive index change inside the cavity but also by the absorption change inside the cavity. With the purpose of expanding the limited bandwidth of such modulator, devices with short passive cavities are designed and fabricated, the results are described and trade-offs between modulation depth and bandwidth will be discussed. In order to solve the problem of alignment and expand the functionality of Fabry-Perot modulators further, vertically coupled cavity devices with each cavity being electrically controlled independently have been developed. Both a coupled cavity modulator and an integrated light emitting diode with a transmission Fabry-Perot modulator are demonstrated; the first device enhances the modulation bandwidth while the second device has the potential of combining the advantage of high speed operation of MQWs modulators with the long lifetime and low cost of light

  4. Measurement of the carrier envelope offset frequency of a femtosecond frequency comb using a Fabry-Perot interferometer

    International Nuclear Information System (INIS)

    Basnak, D V; Bikmukhametov, K A; Dmitrieva, N I; Dmitriev, Aleksandr K; Lugovoi, A A; Pokasov, P V; Chepurov, S V

    2010-01-01

    A method for measuring the carrier envelope offset (CEO) frequency of the femtosecond frequency comb with a bandwidth of less than one octave by using a Fabry-Perot interferometer is proposed and experimentally demonstrated. (laser components)

  5. 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

  6. Experience with measuring of the spectra line profile by means of the Fabry-Perot interferometer

    International Nuclear Information System (INIS)

    Brablec, A.; Kapicka, V.; Stastny, F.

    1988-01-01

    Results of plasma diagnostics by means of the Fabry-Perot interferometer are very sensitive to a right adjustment, a choice of both the working diaphragm and exposition time, etc. Furthermore, a choice of adequate methods applied to the calculation of plasma parameters from experimental data is very important. As it is very difficult to verify the validity of measured results in this case, a sufficient attention was not given to these problems and at present we find only few really useful information in literature, which would correspond with conterporary level of technique. In this paper there is summarized our experience obtained during many years use of the Fabry-Perot interferometer in plasma diagnostics. (author)

  7. Theoretical and experimental study of the dynamic behavior of a nonlinear Fabry-Perot interferrometer

    International Nuclear Information System (INIS)

    Bischofberger, T.; Shen, Y.R.

    1979-01-01

    We have studied theoretically and experimentally the dynamic behavior of a nonlinear Fabry-Perot interferrometer filled with a Kerr medium. The Fabry-Perot responses ranging from extremely transient to quasi-steady-state in various modes of operation are considered. The experimental results are in excellent agreement with theory. It is shown that the quasi-steady-state operation requires not only a medium response time much smaller than the cavity round-trip time, but also a characteristic time of the input intensity variation several hundred times larger than the cavity round-trip time. Even in the quasi-steady-state limit, optical switching is often featured by overshoot and ringing after switching. The switching speed is limited by the cavity buildup time

  8. 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.

  9. Experimental study of neutron-optical potential with absorption using Fabry-Perot magnetic resonator

    International Nuclear Information System (INIS)

    Hino, M.; Tasaki, S.; Ebisawa, T.; Kawai, T.; Achiwa, N.; Yamazaki, D.

    1999-01-01

    Complete text of publication follows. Recently spin precession angles of neutrons tunneling and non-tunneling through [Permalloy45(PA)-germanium(Ge)]-PA Fabry-Perot magnetic resonator have been observed [1]. The spin precession angle is well reproduced by the theoretical phase difference of up and down spin neutron wave function based on one-dimensional Schroedinger equation using optical potential model [2]. Spin precession angle and transmission probability of neutron through PA-(Ge/Gd)-PA Fabry-Perot magnetic resonator are presented, where the gap(Ge/Gd) layer consists of germanium and gadolinium atoms, and the optical potential model for magnetic multilayer system with absorption is discussed. (author) [1] M. Hino, et al., Physica B 241-243, 1083 (1998).; [2] S. Yamada, et al., Annu. Rep. Res. Reactor Inst. Kyoto Univ. 11, 8 (1978)

  10. Subwavelength sound screening by coupling space-coiled Fabry-Perot resonators

    Science.gov (United States)

    Elayouch, A.; Addouche, M.; Farhat, M.; Khelif, A.

    2017-08-01

    We explore broadband and omnidirectional low frequency sound screening based on locally resonant acoustic metamaterials. We show that the coupling of different resonant modes supported by Fabry-Perot cavities can efficiently generate asymmetric lineshapes in the transmission spectrum, leading to a broadband sound opacity. The Fabry-Perot cavities are space-coiled in order to shift the resonant modes under the diffraction edge, which guaranty the opacity band for all incident angles. Indeed, the deep subwavelength feature of the cavities leads to avoid diffraction that have been proved to be the main limitation of omnidirectional capabilities of locally resonant perforated plates. We experimentally reach an attenuation of few tens of dB at low frequency, with a metamaterial thickness fifteen times smaller than the wavelength (λ / 15) . The proposed design can be considered as a new building block for acoustic metasurfaces having a high level of manipulation of acoustic waves.

  11. On-Chip High-Finesse Fabry-Perot Microcavities for Optical Sensing and Quantum Information

    Directory of Open Access Journals (Sweden)

    Mohammad H. Bitarafan

    2017-07-01

    Full Text Available For applications in sensing and cavity-based quantum computing and metrology, open-access Fabry-Perot cavities—with an air or vacuum gap between a pair of high reflectance mirrors—offer important advantages compared to other types of microcavities. For example, they are inherently tunable using MEMS-based actuation strategies, and they enable atomic emitters or target analytes to be located at high field regions of the optical mode. Integration of curved-mirror Fabry-Perot cavities on chips containing electronic, optoelectronic, and optomechanical elements is a topic of emerging importance. Micro-fabrication techniques can be used to create mirrors with small radius-of-curvature, which is a prerequisite for cavities to support stable, small-volume modes. We review recent progress towards chip-based implementation of such cavities, and highlight their potential to address applications in sensing and cavity quantum electrodynamics.

  12. 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.

  13. The Characteristics in the Sensitivity of Microfiber Fabry-Perot Interferometric Transducers

    Science.gov (United States)

    Wang, Xiuxin; Li, Zhangyong; Lin, Jinzhao; Wang, Wei; Tian, Yin; Pang, Yu

    2018-01-01

    We inscribe a Fabry-Perot (FP) resonator in the microfiber utilizing the 193-nm UV exposure and the phase mask technique. Some new characteristics in contrast to the conventional counterparts are measured, which are attributed to the index change in the grating and the dispersion of the effective grating length, respectively. The FP spectral dependencies on external strain, temperature, and refractive index are investigated. Our fabricated structures can have potential of acting as ultrasonic transducers and photo acoustic imaging.

  14. Shot noise in gravitational-wave detectors with Fabry-Perot arms.

    Science.gov (United States)

    Lyons, T T; Regehr, M W; Raab, F J

    2000-12-20

    Shot-noise-limited sensitivity is calculated for gravitational-wave interferometers with Fabry-Perot arms, similar to those being installed at the Laser Interferometer Gravitational-Wave Observatory (LIGO) and the Italian-French Laser Interferometer Collaboration (VIRGO) facility. This calculation includes the effect of nonstationary shot noise that is due to phase modulation of the light. The resulting formula is experimentally verified by a test interferometer with suspended mirrors in the 40-m arms.

  15. 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...

  16. Fabry-Perot ground-based observations of comets and the Jupiter plasma torus

    International Nuclear Information System (INIS)

    Scherb, F.; Roesler, F.L.

    1988-01-01

    The Wisconsin 150 mm dual etalon Fabry-Perot spectrometer is a powerful instrument for the study of diffuse emission sources such as cometary atmospheres, the Jupiter plasma torus, and various emission nebulae. Since 1985, researchers have concentrated their efforts on extensive observations of Comet Halley and the analysis of the data. Images of Comet Halley in (OI)6300 Angstrom emission were analyzed to obtain the spatial distribution of O(1D) in the cometary atmosphere. The narrow spectral bandpass of the Fabry-Perot (0.2 Angstrom) eliminated contamination from terrestrial airglow (OI)6300 and cometary NH2 lines in the nearby spectrum. The results were modelled to provide photodestruction lifetimes of cometary water abd OH, the predominant parents of O(1D). The Fabry-Perot was also used in the scanning mode to obtain measurements of (OI)6300 and Balmer alpha emissions which were used to determine the H, O(1D) and water production rates as a function of heliocentric distance, both pre-perihelion and post-perihelion. Researchers also analyzed high resolution spectra of the NH2 (0,8,0) band in the 6300 Angstrom region to obtain preliminary values of the NH2 production rate. Assuming NH3 is the major parent of NH2, researchers found that the abundance ratio NH3/water is about (0.12 plus or minus 0.04 percent), assuming thermal equilibrium for the level populations of NH2

  17. 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.

  18. Fiber-Optic Temperature Sensor Using a Thin-Film Fabry-Perot Interferometer

    Science.gov (United States)

    Beheim, Glenn

    1997-01-01

    A fiber-optic temperature sensor was developed that is rugged, compact, stable, and can be inexpensively fabricated. This thin-film interferometric temperature sensor was shown to be capable of providing a +/- 2 C accuracy over the range of -55 to 275 C, throughout a 5000 hr operating life. A temperature-sensitive thin-film Fabry-Perot interferometer can be deposited directly onto the end of a multimode optical fiber. This batch-fabricatable sensor can be manufactured at a much lower cost than can a presently available sensor, which requires the mechanical attachment of a Fabry-Perot interferometer to a fiber. The principal disadvantage of the thin-film sensor is its inherent instability, due to the low processing temperatures that must be used to prevent degradation of the optical fiber's buffer coating. The design of the stable thin-film temperature sensor considered the potential sources of both short and long term drifts. The temperature- sensitive Fabry-Perot interferometer was a silicon film with a thickness of approx. 2 microns. A laser-annealing process was developed which crystallized the silicon film without damaging the optical fiber. The silicon film was encapsulated with a thin layer of Si3N4 over coated with aluminum. Crystallization of the silicon and its encapsulation with a highly stable, impermeable thin-film structure were essential steps in producing a sensor with the required long-term stability.

  19. Highly precise nonlinear error calibrating system based on Fabry-Perot interferometer

    Science.gov (United States)

    Ma, Jichi; Li, Yan; Yin, Chunyong

    2008-03-01

    Nanometer measurement has become more and more important in the development of metrology, material science, microelectronics and biology. Heterodyne Fabry-Perot interferometer can be used in the nonlinear error calibration with an accuracy of nanometer and sub-nanometer order. We can get very high resolution by using heterodyne Fabry-Perot interferometer frequency locking technique in theory. However, the measure uncertainty and the stability of results are worse than the expectation's. In this paper, in order to solve the problems of air refrective index change and temperature excursion, we designed the vacuum system that adjusts the interference light path and built it based on NIM's heterodyne Fabry-Perot interferometer. The key in our design is to reduce the thermic balance time and to ensure reliable hermetization of movable components. The influnce of the change of air refractive index to the measured precision was studied, and the approximate formula of vacuum degree that the system requires was concluded. It has been proved in the experiment that the system works steadily. The system's ability of anti-jamming has been improved, and the demand of the measure surroundings has been lowered. Comparing with capacitance displacement measurement instrument, we conclude that the nonlinear degree of this system in the range of 0.35um, which is longer than half of the wavelength of the laser, is better than 3.9nm.

  20. Application of conventional CCD cameras with Fabry-Perot spectrometers for airglow observations

    Energy Technology Data Exchange (ETDEWEB)

    Coakley, M.M.; Roesler, F.L. [Univ. of Wisconsin, Madison, WI (United States). Dept. of Physics

    1994-12-31

    This paper describes Fabry-Perot/CCD annular summing applied to airglow observations. Criteria are developed for determining the optimal rectangular format CCD chip configuration which minimizes dark and read noise. The relative savings in integration time of the imaging Fabry-Perot/CCD system over the pressure-scanned Fabry-Perot/PMT system is estimated for the optimal configuration through calculations of the signal to noise ratios for three extreme (but typical) cases of source and background intensity. The largest savings in integration time in estimated for the daysky thermospheric [O{sup 1}D] (6,300 {angstrom}) case where the bright ({approximately} 5 {times} 10{sup 6}R/{angstrom}) Rayleigh-scattered background dominates the read noise. The long integration times required to obtain useful signal to noise ratios for the faint ({approximately} 10R) nightsky exospheric hydrogen Balmer-{alpha} (6,563 {angstrom}) reduce the importance of the read noise term and yield large savings in integration time. The significance of the read noise term is greatly increased with the very short estimated integration times required for bright ({approximately} 200 R) nightsky lines such as thermospheric [O{sup 1}D]. Alternate CCD formats and applications methods that reduce read noise and provide improved performance in the latter case are compared against the CCD annular summing technique.

  1. A new method used to calibrate Fabry-Perot interferometers on tokamaks

    International Nuclear Information System (INIS)

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

    1993-01-01

    Fabry-Perot interferometers are routinely used on the Tore Supra tokamak in order to measure the electron cyclotron emission spectrum especially in the optically thick region (150-300 GHz) for which the intensity is proportional to the electron temperature. In order to give the electron temperature in keV, it is necessary to calibrate the spectral measurements. In practice, one has to determine the calibration curve. The power levels involved in calibration of Fabry-Perot interferometers used on large tokamaks are generally not compatible with classical data processing techniques such as coherent addition or synchronous detection. A new method is presented in this paper able to detect DC signals as low as 0.1 nV. It is based on a proper reduction of the detection frequency bandwidth. The principle of this method is the following: The source signal is chopped and coherently added over N turns of the chopper. The resulting signal is then Fourier analyzed. One finally takes the amplitude at the chopper frequency which allows a much better filtering of the noise. Incident powers less than 1 pW have thus been measured. Till now and probably due to the difficulties detailed above, absolute calibration of Fabry-Perot interferometers has not yet been achieved for applications to plasmas diagnostics in large fusion devices. The method presented here has been first used to achieve this goal. The experimental set up is briefly described and the method detailed. Results on plasma and comparison of the method with more conventional techniques are presented

  2. Study of Fabry-Perot Etalon Stability and Tuning for Spectroscopic Rayleigh Scattering

    Science.gov (United States)

    Clem, Michelle M.; Mielke-Fagan, Amy F.; Elam, Kristie A.

    2010-01-01

    The Fabry-Perot interferometer is a commonly employed instrument for resolving the spectrum of molecular Rayleigh scattered light for the purpose of evaluating flow properties such as gas velocity and temperature. Rayleigh scattered light from a focused laser beam can be directly imaged through a solid Fabry-Perot etalon onto a CCD detector to provide the spectral content of the scattered light. The spatial resolution of the measurements is governed by the locations of interference fringes. The location of the fringes can be changed by altering the etalon?s physical characteristics, such as thickness and index of refraction. For a fused silica solid etalon the physical properties can be adjusted by changing the etalon temperature; hence changing the order of the interference pattern and the physical fringe locations. Controlling the temperature of the etalon can provide for a slow time-response spatial scanning method for this type of etalon system. A custom designed liquid crystal Fabry-Perot (LCFP) can provide for a fast time-response method of scanning the etalon system. Voltage applied to the liquid crystal interface sets the etalon?s properties allowing Rayleigh measurements to be acquired at varying spatial locations across the image of the laser beam over a very short time period. A standard fused silica etalon and a tunable LCFP etalon are characterized to select the system that is best suited for Rayleigh scattering measurements in subsonic and supersonic flow regimes. A frequency-stabilized laser is used to investigate the apparent frequency stability and temperature sensitivity of the etalon systems. Frequency stability and temperature sensitivity data of the fused silica and LCFP etalon systems are presented in this paper, along with measurements of the LCFP etalon?s tuning capabilities. Rayleigh scattering velocity measurements with both etalon systems are presented, in an effort to determine which etalon is better suited to provide optical flow

  3. Fiber-Optic Anemometer Based on Silicon Fabry-Perot Interferometer

    Science.gov (United States)

    2015-11-05

    oplir ;;nemom tor bm;o~n sil•r.on Fabry Perot •ntorfcromeler AUTHOR(s) LEGAL NAMLS(s) OF RECORD (First, 1.11, Last), CODE, (Afflliat.on If not NRL...f, oo •• " • ~ OII Ct’ THIS f’ORM CANCELS AND SUPERSEOES All. P~EVIOUS \\I!:RSI Fiber-optic anemometer based on silicon Fabry -Pérot...monitoring, etc. In this paper, we propose a new anemometer which consists of a Fabry -Pérot interferometer (FPI) implemented using a thin silicon mounted

  4. Study of a maser with eight ammonia beams with a Fabry-Perot resonator

    International Nuclear Information System (INIS)

    Valentin, M.

    1978-01-01

    We present a maser with eight ammonia beams. The resonator is a Fabry-Perot interferometer with a plane reflector and a concave reflector. With this device we have reached a power of 0.2 μW at 23870 MHz. The experimental results show that the behaviour of the maser at low level and high level of oscillation is very different. We resume and analyse the principal results we have obtained with an electric field having one or two peaks along the molecular trajectory

  5. Stabilization of a Fabry-Perot interferometer using a suspension-point interferometer

    International Nuclear Information System (INIS)

    Aso, Y.; Ando, M.; Kawabe, K.; Otsuka, S.; Tsubono, K.

    2004-01-01

    A suspension-point interferometer (SPI) is an auxiliary interferometer for active vibration isolation, implemented at the suspension points of the mirrors of an interferometric gravitational wave detector. We constructed a prototype Fabry-Perot interferometer equipped with an SPI and observed vibration isolation in both the spectrum and transfer function. The noise spectrum of the main interferometer was reduced by 40 dB below 1 Hz. Transfer function measurements showed that the SPI also produced good vibration suppression above 1 Hz. These results indicate that SPI can improve both the sensitivity and the stability of the interferometer

  6. Correlated-photon-pair emission from a cw-pumped Fabry-Perot microcavity

    Science.gov (United States)

    Langerfeld, Thorsten F.; Meyer, Hendrik M.; Köhl, Michael

    2018-02-01

    We study a dispersion-compensated high-finesse optical Fabry-Perot microcavity under high-intensity cw pumping. The Kerr nonlinearity in the optical coatings causes a spontaneous four-wave mixing process, which leads to the emission of time-correlated photon pairs. The photon frequencies are shifted by ±1 free spectral range relative to the pump frequency. This setup allows for constructing a photon-pair source with precisely adjustable frequency difference between the emitted photons, which may have applications in quantum communication.

  7. Input-output relations for a three-port grating coupled Fabry-Perot cavity

    OpenAIRE

    Bunkowski, Alexander; Burmeister, Oliver; Danzmann, Karsten; Schnabel, Roman

    2005-01-01

    We analyze an optical three-port reflection grating by means of a scattering matrix formalism. Amplitude and phase relations among the three ports, i.e., the three orders of diffraction, are derived. Such a grating can be used as an all-reflective, low-loss coupler to Fabry-Perot cavities. We derive the input-output relations of a three-port grating coupled cavity and find distinct properties that are not present in two-port coupled cavities. The cavity relations further reveal that the three...

  8. 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.

  9. Characterization and modeling of Fabry-Perot ultrasound sensors with hard dielectric mirrors for photoacoustic imaging.

    Science.gov (United States)

    Buchmann, Jens; Guggenheim, James; Zhang, Edward; Scharfenorth, Chris; Spannekrebs, Bastian; Villringer, Claus; Laufer, Jan

    2017-06-10

    A Fabry-Perot ultrasound sensor with nonhygroscopic dielectric mirrors made out of Ta 2 O 5 and SiO 2 for use in photoacoustic tomography is described. The sensor offers flat frequency response up to 36 MHz, low noise-equivalent pressure (70 Pa), and near-omnidirectional response up to 20 MHz as well as optical transparency for near-infrared illumination. A numerical model was developed to predict its frequency response, and the results were validated experimentally. An image of the human palm was acquired to demonstrate in vivo imaging capabilities.

  10. A hyperspectral imager based on a Fabry-Perot interferometer with dielectric mirrors.

    Science.gov (United States)

    Zucco, Massimo; Pisani, Marco; Caricato, Valentina; Egidi, Andrea

    2014-01-27

    In this paper we present a new hyperspectral imager based on a Fabry-Perot interferometer with low reflectivity dielectric mirrors. This set-up has been validated by measuring hypercubes of scenes containing emitting bodies and reflective surfaces in the visible region and compared with success with reference spectra. The system is based on dielectric mirrors which, with respect to similar systems based on metallic mirrors, have lower losses at lower cost and are available off-the-shelf. The spectra calculation is carried out with a Fourier transform based algorithm which takes into account the not negligible dispersion of the mirrors.

  11. An All Fiber Intrinsic Fabry-Perot Interferometer Based on an Air-Microcavity

    Directory of Open Access Journals (Sweden)

    Ruth I. Mata-Chávez

    2013-05-01

    Full Text Available In this work an Intrinsic Fabry-Perot Interferometer (IFPI based on an air-microcavity is presented. Here the air microcavity, with silica walls, is formed at a segment of a hollow core photonic crystal fiber (HCPCF, which is fusion spliced with a single mode fiber (SMF. Moreover, the spectral response of the IFPI is experimentally characterized and some results are provided. Finally, the viability to use the IFPI to implement a simple, compact size, and low cost refractive index sensor is briefly analyzed.

  12. 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.

  13. Accurate Parameters of the Mass Distribution in Spiral Galaxies: 1. Fabry - Perot Observations of NGC 5585

    OpenAIRE

    Blais-Ouellette, Sebastien; Carignan, Claude; Amram, Philippe; Cote, Stephanie

    1999-01-01

    Using the example of the Sd galaxy NGC 5585, it is shown that high resolution 2-D HII kinematical data are necessary to determine accurately the parameters of the mass distribution in spirals. New CFHT Fabry-Perot Halpha observations are combined with low resolution (20") Westerbork HI data to study its mass distribution. Using the combined rotation curve and best fit models, it can be seen that M/L of the luminous disk goes from 0.3 using only the HI rotation curve, to 0.8 using both the opt...

  14. OPTICAL FIBER FABRY-PEROT CAVITIES FOR SENSING TEMPERATURE, STRAIN AND MAGNETIC FIELD

    OpenAIRE

    LARISSA MARIA BESERRA SOARES

    2015-01-01

    Nesta dissertação foram discutidos os resultados obtidos com um interferômetro Fabry-Perot intrínseco (FPI) a fibra óptica, para sensoriamento de deformação longitudinal, temperatura e campo magnético. O FPI foi construído através da emenda de uma fibra capilar entre dois pedaços de fibra padrão de telecomunicação, formando uma cavidade de ar retangular. Esta cavidade, quando atua como um sensor de deformação longitudinal, possui uma sensibilidade nove vezes maior que uma tí...

  15. 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)

  16. Canard orbits in Fabry-Perot cavities induced by radiation pressure and photothermal effects

    Science.gov (United States)

    Marino, F.; de Rosa, M.; Marin, F.

    2006-02-01

    A theoretical study of a high-finesse Fabry-Perot cavity considering radiation pressure and photothermal displacement is reported. We show that the competition between these two effects induces a different kind of dynamic behavior in such a system, consisting of canard orbits and excitability. The transition between the excitable regime and the canard oscillations, occurring through a supercritical Hopf bifurcation, appears in an order compatible with the van der Pol FitzHugh-Nagumo equations. Besides its interest as a study of general nonlinear dynamics, the characterization of the effects described is critical for high sensitivity interferometric displacement measurements as those employed for gravitational waves detection.

  17. Seeing-limited radial velocity field mapping of extended emission line sources using a new imaging Fabry-Perot system

    International Nuclear Information System (INIS)

    Tayler, K.; Atherton, P.D.

    1980-01-01

    TAURUS, a new Fabry-Perot imaging device, designed to obtain complete seeing-limited radial velocity field maps of extended emission-line sources, is described. A servo-controlled Fabry-Perot is used with a focal reducer and a two-dimensional photon-counting (area detector) system, to obtain the velocity information. The system has been fully tested and the first observations of the highly complex velocity field of the irregular galaxy, M82, are used to illustrate the power of the instrument. (author)

  18. Correction of Thermal Deviations of Fabry-Perot Resonator Based Measurements of Specific Gases in Millimeter Wave Bands

    Directory of Open Access Journals (Sweden)

    J. Libich

    2012-04-01

    Full Text Available Due to the thermal expansivity of the material used in the Fabry-Perot resonator mirrors, the resonator cavity length can change and this might therefore have an impact on the resonant frequency during high-resolution spectroscopy measurements. Based on measurements and simulations, this paper discusses the influences of temperature on the precise determination of gas attenuation measured in a Fabry-Perot resonator. Several measures to mitigate such influence and to correct the measured results were tested. A correction method for the measured data was proposed.

  19. Tilted short base Fabry-Perot interferometer with inverted resonances in feedback system of widely tunable linear laser

    International Nuclear Information System (INIS)

    Moiseev, A A; Gelikonov, G V; Gelikonov, V M; Mashcovitch, E A

    2010-01-01

    The method of spectral selection based on weak coupling between a tilted short Fabry-Perot interferometer and a semiconductor optical amplifier has been proposed. An unusual effect was discovered at a certain inclination. Narrowband spectral maxima are observed in the light backreflected from a tilted short base Fabry-Perot interferometer at natural resonances. To demonstrate possible use of this effect for creation of selective feedback in a laser, a semiconductor laser with wavelength tuning range of ±10 nm at central wavelength 1290 nm and coherence length 8 mm has been developed

  20. 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.

  1. Vanadium dioxide based Fabry-Perot emitter for dynamic radiative cooling applications

    Science.gov (United States)

    Taylor, Sydney; Yang, Yue; Wang, Liping

    2017-08-01

    An asymmetric Fabry-Perot emitter is proposed with a lossless dielectric spacer inserted between a vanadium dioxide (VO2) thin film and an opaque aluminum substrate. Switchable mid-infrared emittance has been achieved due to the insulator-to-metal transition of VO2. When VO2 is dielectric below 341 K, the structure is highly reflective, thereby minimizing thermal radiation loss. Above 345 K, the VO2 becomes metallic and forms a Fabry-Perot resonance cavity with high broadband emissivity around 10 μm wavelength, providing a radiative cooling effect due to enhanced thermal emission. The radiative properties are calculated via a uniaxial transfer matrix method and Bruggeman effective medium theory. The physical mechanisms that provide the observed absorption enhancements are elucidated by examining the total phase shift in the multilayer structure and the phonon modes of VO2. When experiencing the VO2 phase transition, the radiative power of the proposed coating achieves a 6.5 fold enhancement for extraterrestrial spacecraft systems, and 7.3 fold enhancement for terrestrial systems such as buildings, making it a promising choice for dynamic radiative cooling applications in a variable environment. The findings here will facilitate research and development of novel coating materials for radiative cooling applications.

  2. Dynamics of a noncontacting, white light Fabry-Perot interferometric displacement sensor.

    Science.gov (United States)

    Moro, Erik A; Todd, Michael D; Puckett, Anthony D

    2012-07-01

    A white light extrinsic Fabry-Perot interferometer is implemented as a noncontacting displacement sensor, providing robust, absolute displacement measurements with micrometer accuracy at a sampling rate of 10 Hz. This paper presents a dynamic model of the sensing cavity between the sensor probe and the nearby target surface using a Fabry-Perot etalon approach obtained from straightforward electromagnetic field formulations. Such a model is important for system characterization, as the dynamically changing cavity length imparts a Doppler shift on any signals circulating within the sensing cavity. Contrary to previously published results, Doppler-induced shifting within the low-finesse sensing cavity is shown to significantly distort the measurement signal as recorded by the sensor. Experimental and simulation results are compared, and the direct effects of cavity dynamics on the measurement signal are analyzed along with their indirect impact on sensor performance. This document has been approved by Los Alamos National Laboratory for unlimited public release (LA-UR 12-00301).

  3. A Hot-Polymer Fiber Fabry-Perot Interferometer Anemometer for Sensing Airflow.

    Science.gov (United States)

    Lee, Cheng-Ling; Liu, Kai-Wen; Luo, Shi-Hong; Wu, Meng-Shan; Ma, Chao-Tsung

    2017-09-02

    This work proposes the first hot-polymer fiber Fabry-Perot interferometer (HPFFPI) anemometer for sensing airflow. The proposed HPFFPI is based on a single-mode fiber (SMF) endface that is attached to a UV-cured polymer to form an ultracompact fiber Fabry-Perot microcavity. The proposed polymer microcavity was heated using a low-cost chip resistor with a controllable dc driving power to achieve a desired polymer's steady-state temperature (T) that exceeds the T of the surrounding environment. The polymer is highly sensitive to variations of T with high repeatability. When the hot polymer was cooled by the measured flowing air, the wavelength fringes of its optical spectra shifted. The HPFFPI anemometers have been experimentally evaluated for different cavity lengths and heating power values. Experimental results demonstrate that the proposed HPFFPI responses well in terms of airflow measurement. A high sensitivity of 1.139 nm/(m/s) and a good resolution of 0.0088 m/s over the 0~2.54 m/s range of airflow were achieved with a cavity length of 10 μm and a heating power of 0.402 W.

  4. 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 modulation...

  5. Monostatic coaxial 1.5 μm laser Doppler velocimeter using a scanning Fabry-Perot interferometer

    DEFF Research Database (Denmark)

    Rodrigo, Peter John; Pedersen, Christian

    2013-01-01

    We present a laser Doppler velocimeter (LDV) in monostatic coaxial arrangement consisting of off-the-shelf telecom-grade components: a single frequency laser (wavelength λ = 1.5 μm) and a high-finesse scanning Fabry-Perot interferometer (sFPI). In contrast to previous 1.5 μm LDV systems based...

  6. 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.

  7. High reflectivity air-bridge subwavelength grating reflector and Fabry-Perot cavity in AlGaAs/GaAs.

    Science.gov (United States)

    Bisaillon, Eric; Tan, Dawn; Faraji, Behnam; Kirk, Andrew; Chrowstowski, Lukas; Plant, David V

    2006-04-03

    We present a novel air-bridge subwavelength grating reflector with very high reflectivity to be used as a top mirror in a VCSEL structure. We explain the design method, model the structure using both RCWA and FDTD, and predict the characteristics of a Fabry-Perot structure built with this reflector. We describe the fabrication of the suspended grating.

  8. 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.

  9. Estimating the off resonance thermal noise in mirrors, Fabry-Perot interferometers, and delay lines: The half infinite mirror with uniform loss

    International Nuclear Information System (INIS)

    Nakagawa, N.; Gustafson, E.K.; Beyersdorf, Peter T.; Fejer, M.M.

    2002-01-01

    We present an analysis comparing the thermal noise in Fabry-Perot and delay-line interferometers with half-infinite mirrors. With a center to center spot spacing of at least twice the Gaussian beam spot size a delay line produces significantly less phase noise than a comparable Fabry-Perot interferometer for the case of half infinite mirrors at frequencies where test mass thermal noise usually dominates. When the delay-line spots overlap substantially the delay-line produces approximately the same noise as the Fabry-Perot interferometer. For a single bounce these results agree with those based on the method of Levin

  10. 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

  11. High quality factor surface Fabry-Perot cavity of acoustic waves

    Science.gov (United States)

    Xu, Yuntao; Fu, Wei; Zou, Chang-ling; Shen, Zhen; Tang, Hong X.

    2018-02-01

    Surface acoustic wave (SAW) resonators are critical components in wireless communications and many sensing applications. They have also recently emerged as a subject of study in quantum acoustics at the single phonon level. Acoustic loss reduction and mode confinement are key performance factors in SAW resonators. Here, we report the design and experimental realization of high quality factor Fabry-Perot SAW resonators formed in between the tapered phononic crystal mirrors patterned on a GaN-on-sapphire material platform. The fabricated SAW resonators are characterized by both an electrical network analyzer and an optical heterodyne vibrometer. We observed standing Rayleigh waves inside the cavity, with an intrinsic quality factor exceeding 1.3 × 104 at ambient conditions.

  12. Absorption method for determining concentrations using the Fabry-Perot interferometer

    International Nuclear Information System (INIS)

    Zhuravlev, A.A.; Izmailov, A.M.; Kuchinskii, V.V.; Sheikin, E.G.

    1986-01-01

    This study determines a means of processing experimental data using a non-ideal Fabry-Perot interferometer. Using such an instrument, one can ignore distortion induced by the instrument profile in the results of measuring the concentration of atoms. With a priori information (e.g., on the ratio of the gas temperatures for the test and illuminating discharges) the procedure of processing is substantially simplified, and one obtains simple equations for determining the concentrations of atoms in a metal. The effectiveness of this method is analyzed through an example in determining the concentration of atoms in a metal with a discharge in a hollow cathode. As a control for the experiment, the concentration is simultaneously determined by a spectral-sounding technique

  13. Spectrum reshaping of micro-ring resonator via an integrated Fabry-Perot cavity

    Science.gov (United States)

    Wu, Jiayang; Moein, Tania; Xu, Xingyuan; Ren, Guanghui; Mitchell, Arnan; Moss, David J.

    2018-01-01

    We investigate the enhancement in the filtering quality (Q) factor of an integrated micro-ring resonator (MRR) by embedding it in an integrated Fabry-Perot (FP) cavity formed by cascaded Sagnac loop reflectors (SLRs). By using coherent interference within the FP cavity to reshape the transmission spectrum of the MRR, both the Q factor and the extinction ratio (ER) can be greatly improved. The device is theoretically analyzed, and practically fabricated on a silicon-on-insulator (SOI) platform. Experimental results show that up to 11-times improvement in Q factor and an 8-dB increase in ER can be achieved via our proposed method. The impact of varying structural parameters on the device performance is also investigated and verified.

  14. Advancement of Optical Component Control for an Imaging Fabry-Perot Interferometer

    Science.gov (United States)

    Larar, Allen M.; Cook, William B.; Flood, Michael A.; Campbell, Joel F.; Boyer, Charles M.

    2009-01-01

    Risk mitigation activities associated with a prototype imaging Fabry-Perot Interferometer (FPI) system are continuing at the NASA Langley Research Center. The system concept and technology center about enabling and improving future space-based atmospheric composition missions, with a current focus on observing tropospheric ozone around 9.6 micron, while having applicability toward measurement in different spectral regions and other applications. Recent activities have focused on improving an optical element control subsystem to enable precise and accurate positioning and control of etalon plates; this is needed to provide high system spectral fidelity critical for enabling the required ability to spectrally-resolve atmospheric line structure. The latest results pertaining to methodology enhancements, system implementation, and laboratory characterization testing will be reported

  15. 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

  16. Microcomputer control of infrared detector arrays used in direct imaging and in Fabry-Perot spectroscopy

    International Nuclear Information System (INIS)

    Rossano, G.S.

    1989-01-01

    A microcomputer based data acquisition system has been developed for astronomical observing with two-dimensional infrared detector arrays operating at high pixel rates. The system is based on a 16-bit 8086/8087 microcomputer operating at 10 MHz. Data rates of up to 560,000 pixels/sec from arrays of up to 4096 elements are supported using the microcomputer system alone. A hardware co-adder the authors are developing permits data accumulation at rates of up to 1.67 million pixels/sec in both staring and chopped data acquisition modes. The system has been used for direct imaging and for data acquisition in a Fabry-Perot Spectrometer developed by NRL. The hardware is operated using interactive software which supports the several available modes of data acquisition, and permits data display and reduction during observing sessions

  17. High-resolution multi-heterodyne spectroscopy based on Fabry-Perot quantum cascade lasers

    International Nuclear Information System (INIS)

    Wang, Yin; Wang, Wen; Wysocki, Gerard; Soskind, Michael G.

    2014-01-01

    In this Letter, we present a method of performing broadband mid-infrared spectroscopy with conventional, free-running, continuous wave Fabry-Perot quantum cascade lasers (FP-QCLs). The measurement method is based on multi-heterodyne down-conversion of optical signals. The sample transmission spectrum probed by one multi-mode FP-QCL is down-converted to the radio-frequency domain through an optical multi-heterodyne process using a second FP-QCL as the local oscillator. Both a broadband multi-mode spectral measurement as well as high-resolution (∼15 MHz) spectroscopy of molecular absorption are demonstrated and show great potential for development of high performance FP-laser-based spectrometers for chemical sensing

  18. 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.

  19. 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

  20. Hybrid optical fiber Fabry-Perot interferometer for simultaneous measurement of gas refractive index and temperature.

    Science.gov (United States)

    Wang, Ruohui; Qiao, Xueguang

    2014-11-10

    We present a hybrid miniature optical fiber Fabry-Perot interferometer for simultaneous measurement of gas refractive index and temperature. The interferometer is fabricated by cascading two short sections of capillary tubes with different inner diameters. One extrinsic interferometer is based on the air gap cavity formed by the capillary tube with large diameter. Another section of capillary tube with small inner diameter performs as an intrinsic interferometer and also provides a channel enabling gas to enter and leave the extrinsic cavity freely. The experiment shows that the different dips or peaks in fringe exhibit different responses to the changes in gas refractive index and temperature. Owing to this feature, simultaneous measurement of the gas refractive index and temperature can be realized.

  1. Anomalous resonant reflection in a Fabry-Perot cavity filled with weakly scattering medium.

    Science.gov (United States)

    Hao, Ye; Gao, Wentao; Sun, Zhijun

    2018-03-01

    In this work, we fabricated a metallic Fabry-Perot cavity, filled with a weakly scattering medium of unsintered solgel silica, on a glass substrate. We found anomalous asymmetric resonance reflection spectra of this structure, besides the effects of scattering loss in cavity. The asymmetric reflection is shown to be dependent on the media on both sides of the cavity. It is thought that, as the weakly scattering medium locates between highly reflecting boundaries and the cavity length is far less than the mean free path of light in the medium, light scattering in the medium is enhanced at the resonance conditions and the scattering centers act as elementary sources emitting the scattered incoherent light to the outside of the cavity from both its ends. The asymmetric reflection then results from lossy total internal reflection of the scattered light at one of the boundaries, eventually leaking to the outside of the cavity with the higher index and contributing to the measured backside reflectance.

  2. Gas detection with microelectromechanical Fabry-Perot interferometer technology in cell phone

    Science.gov (United States)

    Mannila, Rami; Hyypiö, Risto; Korkalainen, Marko; Blomberg, Martti; Kattelus, Hannu; Rissanen, Anna

    2015-06-01

    VTT Technical Research Centre of Finland has developed a miniaturized optical sensor for gas detection in a cell phone. The sensor is based on a microelectromechanical (MEMS) Fabry-Perot interferometer, which is a structure with two highly reflective surfaces separated by a tunable air gap. The MEMS FPI is a monolithic device, i.e. it is made entirely on one substrate in a batch process, without assembling separate pieces together. The gap is adjusted by moving the upper mirror with electrostatic force, so there are no actual moving parts. VTT has designed and manufactured a MEMS FPI based carbon dioxide sensor demonstrator which is integrated to a cell phone shield cover. The demonstrator contains light source, gas cell, MEMS FPI, detector, control electronics and two coin cell batteries as a power source. It is connected to the cell phone by Bluetooth. By adjusting the wavelength range and customizing the MEMS FPI structure, it is possible to selectively sense multiple gases.

  3. Traveling wave-like Fabry-Perot resonator-based add-drop filters.

    Science.gov (United States)

    Huang, Qingzhong; Liu, Qiang; Xia, Jinsong

    2017-12-15

    We have proposed and studied a novel channel add-drop filter (ADF) based on a single Fabry-Perot resonator. The resonator consists of two mode-conversion Bragg grating reflectors separated by a wide waveguide that laterally coupled to two narrow waveguides. It behaves like a traveling-wave resonator where fields are coupled to the buses in one direction. Compact and narrowband ADFs are achieved with dropping efficiencies higher than 95%, as shown by the three-dimensional finite-difference time-domain simulations. In addition, the proposed device is applied to realize an eight-channel add-drop multiplexer in the C-band by cascading the ADFs with adjusted channel wavelengths.

  4. Measuring concentration fields in microfluidic channels in situ with a Fabry-Perot interferometer.

    Science.gov (United States)

    Vogus, Douglas R; Mansard, Vincent; Rapp, Michael V; Squires, Todd M

    2015-04-07

    Recent advancements in microfluidic technology have allowed for the generation and control of complex chemical gradients; however, few general techniques can measure these spatio-temporal concentration profiles without fluorescent labeling. Here we describe a Fabry-Perot interferometric technique, capable of measuring concentration profiles in situ, without any chemical label, by tracking Fringes of Equal Chromatic Order (FECO). The technique has a sensitivity of 10(-5) RIU, which can be used to track local solute changes of ~0.05% (w/w). The technique is spatially resolved (1 μm) and easily measures evolving concentration fields with ~20 Hz rate. Here, we demonstrate by measuring the binary diffusion coefficients of various solutes and solvents (and their concentration-dependence) in both free solution and in polyethylene glycol diacrylate (PEG-DA) hydrogels.

  5. Development of a tunable Fabry-Perot interferometer UV camera for monitoring sulfur dioxide emissions

    Science.gov (United States)

    Tamminen, J.; Kujanpää, J.; Ojanen, H.; Saari, H.; Näkki, I.; Tukiainen, S.; Kyrölä, E.

    2017-12-01

    We present a novel UV camera for sulfur dioxide emission monitoring.The camera is equipped with a piezo-actuated Fabry-Perot interferometer allowing thefilter transmission to be tuned to match the differential absorption features ofsulfur dioxide in the wavelength region 305-320 nm. The differential absorption structuresare exploited to reduce the interfering effects of weakly wavelength dependent absorbers, suchas aerosols and black carbon, present in the exhaust gas. A data processing algorithm basedon two air gaps of the filter is presented allowing collection of a sufficient signal-to-noise ratio fordetecting sulfur dioxide in the ship plumes even in the designated emission control areas, such as the Baltic Seawhere the sulfur content limit of fuel oil is 0.1 %. First field tests performed inLänsisatama harbour, Helsinki Finland, indicate that sulfur dioxide can be detectedin ship plumes. The camera is light-weight and can be mounted to a drone.

  6. Self-sustained photothermal oscillations in high-finesse Fabry-Perot microcavities

    Science.gov (United States)

    Konthasinghe, Kumarasiri; Velez, Juan Gomez; Hopkins, Adam J.; Peiris, Manoj; Profeta, Luisa T. M.; Nieves, Yamil; Muller, Andreas

    2017-01-01

    We report the experimental investigation of a regime of microscopic Fabry-Perot resonators in which competing light-induced forces—photothermal expansion and photothermal refraction—acting oppositely and on different timescales lead to self-sustained persistent oscillations. Previously concealed as ordinary thermo-optic bistability—a common feature in low-loss resonator physics—these dynamics are visible as fast pulsations in cavity transmission or reflection measurements at sufficiently high time resolution. Their underlying mathematical description is shared by many slow-fast phenomena in chemistry, biology, and neuroscience. Our observations are relevant in particular to microcavity applications in atom optics and cavity quantum electrodynamics, even in nominally rigid structures that have not undergone lithography.

  7. Design of a reconfigurable optical add/drop multiplexer based on tunable Fabry-Perot array

    Science.gov (United States)

    Ye, Jiansen; Wang, Xin; Li, Zhuo; Yang, Yang; Xu, Rui; Shi, Rui

    2015-08-01

    With the development of optical fiber communication, dense wavelength division multiplexing (DWDM) system is important for the rapid management of multi-wavelength in the core node of the optical transmission network. In this paper, a reconfigurable optical add-drop multiplexer (ROADM) based on the tunable Fabry-Perot (F-P) array is proposed. An optical switch with high isolation and low crosstalk is designed by using the characteristics of filtering and tuning for the F-P array. The principle, structure, and function of the tunable F-P array are introduced. The characteristics of filtering and tuning for the F-P filter are also calculated, and the factor for the isolation, crosstalk, response time and insertion loss are analyzed. A single physical channel ROADM with 16 signal channels, which operates in C-band, is designed and optimized by simulation.

  8. Mirror-orientation noise in a Fabry-Perot interferometer gravitational wave detector.

    Science.gov (United States)

    Kawamura, S; Zucker, M E

    1994-06-20

    The influence of angular mirror-orientation errors on the length of a Fabry-Perot resonator is analyzed geometrically. Under conditions in which dominant errors are static or vary slowly over time, the analysis permits a simple prediction of the spectrum of short-term cavity length fluctuations resulting from mirror-orientation noise. The resulting model is applicable to the design of mirror control systems for the Laser Interferometer Gravitational-Wave Observatory, which will monitor separations between mirrored surfaces of suspended inertial test bodies as a way to measure astrophysical gravitational radiation. The analysis is verified by measuring the response of the Laser Interferometer Gravitational- Wave Observatory's 40-m interferometer test-bed to the rotation of its mirrors.

  9. Embedded intrinsic Fabry-Perot optical fiber sensors in cement concrete structures

    Science.gov (United States)

    Kim, Ki S.; Yoo, Jae-Wook; Kim, Seung Kwan; Kim, Byoung Yoon

    1996-05-01

    Intrinsic Fabry-Perot optical fiber sensors were embedded to the tensile side of the 20 cm by 20 cm by 150 cm cement concrete structures. The sensors were attached to the reinforcing steels and then, the cement concretes were applied. It took 30 days for curing the specimens. After that, the specimens were tested with 4-point bending method by a universal testing machine. Strains were measured and recorded by the strain gauges embedded near optical fiber sensors. Output data of fiber sensor showed good linearity to the strain data from the strain gauges up to 2000 microstrain. The optical fiber sensors showed good response after yielding of the structure while embedded metal film strain gauges did not show any response. We also investigated the behavior of the optical fiber sensor when the specimens were broken down. In conclusion, the optical fiber sensors can be used as elements of health monitoring systems for cement concrete infra-structures.

  10. 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.

  11. Highly accurate spectral retardance characterization of a liquid crystal retarder including Fabry-Perot interference effects

    Energy Technology Data Exchange (ETDEWEB)

    Vargas, Asticio [Departamento de Ciencias Físicas, Universidad de La Frontera, Temuco (Chile); Center for Optics and Photonics, Universidad de Concepción, Casilla 4016, Concepción (Chile); Mar Sánchez-López, María del [Instituto de Bioingeniería, Universidad Miguel Hernández, 03202 Elche (Spain); García-Martínez, Pascuala [Departament d' Òptica, Universitat de València, 45100 Burjassot (Spain); Arias, Julia; Moreno, Ignacio [Departamento de Ciencia de Materiales, Óptica y Tecnología Electrónica, Universidad Miguel Hernández, 03202 Elche (Spain)

    2014-01-21

    Multiple-beam Fabry-Perot (FP) interferences occur in liquid crystal retarders (LCR) devoid of an antireflective coating. In this work, a highly accurate method to obtain the spectral retardance of such devices is presented. On the basis of a simple model of the LCR that includes FP effects and by using a voltage transfer function, we show how the FP features in the transmission spectrum can be used to accurately retrieve the ordinary and extraordinary spectral phase delays, and the voltage dependence of the latter. As a consequence, the modulation characteristics of the device are fully determined with high accuracy by means of a few off-state physical parameters which are wavelength-dependent, and a single voltage transfer function that is valid within the spectral range of characterization.

  12. Enhanced dual-band infrared absorption in a Fabry-Perot cavity with subwavelength metallic grating.

    Science.gov (United States)

    Kang, Guoguo; Vartiainen, Ismo; Bai, Benfeng; Turunen, Jari

    2011-01-17

    The performance of infrared (IR) dual-band detector can be substantially improved by simultaneously increasing IR absorptions for both sensor bands. Currently available methods only provide absorption enhancement for single spectral band, but not for the dual-band. The Fabry-Perot (FP) cavity generates a series of resonances in multispectral bands. With this flexibility, we introduced a novel type of dual-band detector structure containing a multilayer FP cavity with two absorbing layers and a subwavelength-period grating mirror, which is capable of simultaneously enhancing the middle wave infrared (MWIR) and the long wave infrared (LWIR) detection. Compared with the bare-absorption-layer detector (common dual-band detector), the optimized FP cavity can provide about 13 times and 17 times absorption enhancement in LWIR and MWIR bands respectively.

  13. On-chip optical phase locking of single growth monolithically integrated Slotted Fabry Perot lasers.

    Science.gov (United States)

    Morrissey, P E; Cotter, W; Goulding, D; Kelleher, B; Osborne, S; Yang, H; O'Callaghan, J; Roycroft, B; Corbett, B; Peters, F H

    2013-07-15

    This work investigates the optical phase locking performance of Slotted Fabry Perot (SFP) lasers and develops an integrated variable phase locked system on chip for the first time to our knowledge using these lasers. Stable phase locking is demonstrated between two SFP lasers coupled on chip via a variable gain waveguide section. The two lasers are biased differently, one just above the threshold current of the device with the other at three times this value. The coupling between the lasers can be controlled using the variable gain section which can act as a variable optical attenuator or amplifier depending on bias. Using this, the width of the stable phase locking region on chip is shown to be variable.

  14. 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.

  15. 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.

  16. 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

  17. Fabry-Perot fiber pressure sensor based on white light interferometry and intensity demodulation method

    Science.gov (United States)

    Guo, Zhenwu; Li, Weixiang; Zhang, Dapeng; Pan, Yong; Meng, Qingbin; Liu, Guangwei; Ge, Fuwei; Zhang, Xian

    2009-05-01

    We have designed an intensity-demodulated sensing system based on Fabry-Perot interferometer and fiber Bragg grating (FBG) for pressure measurement. The structure of the sensor probe is presented. It is an optical fiber extrinsic Fabry-Perot interferometer(EFPI) composed of silica tube and optical fibers. The variable quantity of cavity length of the EFPI is equal to that of silica tube, which has direct proportion to external pressure. The sensing system is interrogated by broadband light. In order to compensate intensity fluctuation, we use an FBG as a narrow band filter to obtain the sensing signal and reference signal from white-light interference fringe returned from EFPI. The sensing signal is in the reflected beam from FBG, and the reference signal is contained in reflected beam and transmitted beam of FBG simultaneously. Then two output light signals are transformed into current signals by two photodiodes. Subsequently two current signals are processed at the same time. After the signals being treated with circuit, the inherent disadvantage of intensity-demodulated sensor is removed. It is also to say the sensing system has immunity from the drift of light source power and fluctuation in fiber attenuation by using only a FBG. Meanwhile, the system has advantages of fast response, simple circuitry, strong ability of intensity compensation and low cost. Experimental results show that the experimental data are consistent with theoretical analysis. The dynamic range of sensor is from 0 to 500KPa, and the resolution reaches to 0.5KPa. The sensing system can be used to measure pressure in inflammable and explosive circumstance such as oil height of super oil storage tanks.

  18. Parametric oscillation of a moving mirror driven by radiation pressure in a superconducting Fabry-Perot resonator system

    International Nuclear Information System (INIS)

    Chiao, Raymond Y; Martinez, Luis A; Minter, Stephen J; Trubarov, Alexey

    2012-01-01

    A moving pellicle superconducting mirror, which is driven by radiation pressure on its one side and the Coulomb force on its other side, can become a parametric oscillator that can generate microwaves when placed within a high-Q superconducting Fabry-Perot resonator system. A paraxial-wave analysis shows that the fundamental resonator eigenmode needed for parametric oscillation is the TM 011 mode. A double Fabry-Perot structure is introduced to resonate the pump and idler modes, but reject the parasitic anti-Stokes mode. The threshold for oscillation is estimated based on the radiation-pressure coupling of the pump to the signal and idler modes and indicates that the experiment is feasible to perform.

  19. Fast charge exchange spectroscopy using a Fabry-Perot spectrometer in the JIPP TII-U tokamak

    International Nuclear Information System (INIS)

    Ida, K.; Xu, J.; Sato, K.N.; Sakakita, H.

    1997-01-01

    A new charge exchange spectroscopic technique using a Fabry-Port spectrometer has been developed to increase the photon flux at the detector, and to improve the time resolution of ion temperature and plasma rotation velocity measurements. The spectral resolution is obtained by arranging two-dimensional fiber-optics and a two-dimensional detector at the focal plane of a coupled lens located on both sides of a Fabry-Perot spectrometer. The effective finesse (the ratio of the spectral resolution to the free spectral range) of the Fabry-Perot interferometer in this system is 14. The time evolution of the ion temperature is obtained with a time resolution of 125 μs and with a spatial resolution of 3 cm (eight channels). (orig.)

  20. High sensitivity axial strain and temperature sensor based on dual-frequency optoelectronic oscillator using PMFBG Fabry-Perot filter.

    Science.gov (United States)

    Yin, Bin; Wang, Muguang; Wu, Songhua; Tang, Yu; Feng, Suchun; Zhang, Hongwei

    2017-06-26

    A dual-frequency optoelectronic oscillator (OEO) incorporating a polarization-maintaining fiber Bragg grating (PMFBG) Fabry-Perot filter for high-sensitivity and high-speed axial strain and temperature sensing is proposed and experimentally demonstrated. In the OEO loop, two oscillation frequencies are determined by a PMFBG Fabry-Perot filter with two ultra-narrow notches and two laser sources which operate as a dual-passband microwave photonic filter. The fiber birefringence affected by axial strain is far less than the temperature. Through monitoring the variations of two oscillating frequencies and beat frequency, the simultaneous measurement for the axial strain and temperature is realized. The sensitivities of the proposed OEO sensor for axial strain and temperature are experimentally measured to be as high as 100.6 or 100.5 MHz/με and -41 MHz/°C, respectively.

  1. 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...

  2. 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.

  3. Some aspects of vacuum ultraviolet radiation physics

    CERN Document Server

    Damany, Nicole; Vodar, Boris

    2013-01-01

    Some Aspects of Vacuum Ultraviolet Radiation Physics presents some data on the state of research in vacuum ultraviolet radiation in association with areas of physics. Organized into four parts, this book begins by elucidating the optical properties of solids in the vacuum ultraviolet region (v.u.v.), particularly the specific methods of determination of optical constants in v.u.v., the properties of metals, and those of ionic insulators. Part II deals with molecular spectroscopy, with emphasis on the spectra of diatomic and simple polyatomic molecules, paraffins, and condensed phases. Part III

  4. Design and performance modelling of a wavelength specific asymmetric Fabry-Perot modulator

    International Nuclear Information System (INIS)

    Nott, G.J.; Goldys, E.M.; Grant, K.J

    1996-01-01

    Asymmetric Fabry-Perot modulators (AFPM's) combine the nonlinear effects present in multiple quantum well (MQW) structures with the interferometric operation of a Fabry-Perot cavity, thus increasing the modulator performance over simple transmission or reflection devices. Parameters commonly used to evaluate the performance of a multiple quantum well optical modulator are: its contrast ratio, dynamic range, and insertion loss. We present the design analysis of a GaAs/AlGaAs AFPM for operation at 850 nm with respect to these performance parameters. The reflectivity of the Bragg stack forming the back mirror of the AFPM was found for different layer materials. The number of layers and the materials used, was determined to ensure a mirror with a high maximum reflectivity over a range of wavelengths. A high reflectivity back mirror minimises the insertion loss while a broad reflectivity maxima reduces the dependence of device operation on the growth quality of the stack. Computations of transition energies of the MQW showed that for device operation at 850 nm, a well width of 84.8 Angstroms (30 atomic monolayers) was required. Our calculations confirm those reported elsewhere, that show for this well width the barrier width may be reduced to approximately 50 Angstroms without superlattice coupling causing a serious degradation in the width of the excitonic peaks. The characteristics of the primary exciton peak have a large effect on the performance of the AFPM. Calculations indicated that narrow linewidths and large Stark shifts are required for an optimised contrast ratio, dynamic range and insertion loss. We demonstrate that with exciton linewidths of 3 nm and Stark shifts of 15 nm, contrast ratios of 900 are achievable. Of greater importance to the performance of the AFPM is the quality of the epitaxial growth and the accuracy of the cavity phase matching. It was found that if the thickness of the cavity deviates by only 10 monolayers either side of the optimum

  5. First Light from Triple-Etalon Fabry-Perot Interferometer for Atmospheric OI Airglow (6300 A)

    Science.gov (United States)

    Watchorn, S.; Noto, J.; Pedersen, T.; Betremieux, Y.; Migliozzi, M.; Kerr, R. B.

    2006-05-01

    Scientific Solutions, Inc. (SSI) has developed a triple-etalon Fabry-Perot interferometer (FPI) to observe neutral winds in the ionosphere by measuring neutral oxygen (O I) emission at 630.0 nm during the day. This instrument is to be deployed in the SSI airglow building at the Cerro Tololo observatory (30.17S 70.81W) in Chile, in support of the Comm/Nav Outage Forecast System (C/NOFS) project. Post-deployment observation will be made in conjunction with two other Clemson University Fabry-Perots in Peru, creating a longitudinal chain of interferometers for thermospheric observations. These instruments will make autonomous day and night observations of thermospheric dynamics. Instruments of this type can be constructed for a global chain of autonomous airglow observatories. The FPI presented in this talk consists of three independently pressure-controlled etalons, fed collimated light by a front optical train headed by an all-sky lens with a 160-degree field of view. It can be controlled remotely via a web-based service which allows any internet-connected computer to mimic the control computer at the instrument site. In fall 2005, the SSI system was first assembled at the Millstone Hill Observatory in Westford, Massachusetts, and made day and evening observations. It was then moved to the High-frequency Active Auroral Research Project (HAARP) site in Gakona, Alaska, to participate in joint optical/ionospheric heating campaigns. Additionally, natural airglow observations were made, both locally and remotely via the internet from Massachusetts. The Millstone and HAARP observations with two etalons yielded strong 630-nm atmospheric Fraunhofer absorption lines, with some suggestion of the Ring effect. By modeling the atmospheric absorption line as the constant times the corresponding solar absorption -- itself modeled as a Gaussian plus a polynomial -- the absorption feature is subtracted, leaving only the emission feature. Software ring-summing tools developed at the

  6. Vacuum-Ultraviolet Photovoltaic Detector.

    Science.gov (United States)

    Zheng, Wei; Lin, Richeng; Ran, Junxue; Zhang, Zhaojun; Ji, Xu; Huang, Feng

    2018-01-23

    Over the past two decades, solar- and astrophysicists and material scientists have been researching and developing new-generation semiconductor-based vacuum ultraviolet (VUV) detectors with low power consumption and small size for replacing traditional heavy and high-energy-consuming microchannel-detection systems, to study the formation and evolution of stars. However, the most desirable semiconductor-based VUV photovoltaic detector capable of achieving zero power consumption has not yet been achieved. With high-crystallinity multistep epitaxial grown AlN as a VUV-absorbing layer for photogenerated carriers and p-type graphene (with unexpected VUV transmittance >96%) as a transparent electrode to collect excited holes, we constructed a heterojunction device with photovoltaic detection for VUV light. The device exhibits an encouraging VUV photoresponse, high external quantum efficiency (EQE) and extremely fast tempera response (80 ns, 10 4 -10 6 times faster than that of the currently reported VUV photoconductive devices). This work has provided an idea for developing zero power consumption and integrated VUV photovoltaic detectors with ultrafast and high-sensitivity VUV detection capability, which not only allows future spacecraft to operate with longer service time and lower launching cost but also ensures an ultrafast evolution of interstellar objects.

  7. Fiber ring laser sensor based on Fabry-Perot cavity interferometer for temperature sensing

    Science.gov (United States)

    Zou, Hui; Ma, Lei; Xiong, Hui; Zhang, Yunshan; Li, Yong Tao

    2018-01-01

    A ring laser temperature sensor based on a novel reflective fiber Fabry-Perot (F-P) interferometer air cavity is proposed and experimentally demonstrated. The reflective F-P air cavity, which consists of a segment of glass capillary inserted between two single-mode fibers, is utilized as a sensing element as well as as a filter in the fiber ring cavity. As temperature increases, the reflection spectra of the F-P sensor move towards the longer wavelength, and then cause lasing wavelength shifts. By monitoring the variation of lasing wavelength, we obtain a temperature sensor system with a high temperature sensitivity of 0.249 nm °C-1, a narrow 3 dB bandwidth of 0.1514 nm, and a high signal-to-noise ratio of 52 dB. Moreover, it is convenient to fabricate the sensor head, and the stability is very good, giving it a wide range of applications.

  8. Millimeter Wave Fabry-Perot Resonator Antenna Fed by CPW with High Gain and Broadband

    Directory of Open Access Journals (Sweden)

    Xue-Xia Yang

    2016-01-01

    Full Text Available A novel millimeter wave coplanar waveguide (CPW fed Fabry-Perot (F-P antenna with high gain, broad bandwidth, and low profile is reported. The partially reflective surface (PRS and the ground form the F-P resonator cavity, which is filled with the same dielectric substrate. A dual rhombic slot loop on the ground acts as the primary feeding antenna, which is fed by the CPW and has broad bandwidth. In order to improve the antenna gain, metal vias are inserted surrounding the F-P cavity. A CPW-to-microstrip transition is designed to measure the performances of the antenna and extend the applications. The measured impedance bandwidth of S11 less than −10 dB is from 34 to 37.7 GHz (10.5%, and the gain is 15.4 dBi at the center frequency of 35 GHz with a 3 dB gain bandwidth of 7.1%. This performance of the antenna shows a tradeoff among gain, bandwidth, and profile.

  9. Probing the energy structure of positronium with a 203 GHz Fabry-Perot Cavity

    Energy Technology Data Exchange (ETDEWEB)

    Suehara, T; Namba, T; Kobayashi, T [International Center for Elementary Particle Physics (ICEPP), University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-0033 (Japan); Miyazaki, A; Ishida, A; Asai, S [Department of Physics, Graduate School of Science, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 133-0033 (Japan); Saito, H [Department of General Systems Studies, Graduate School of Arts and Sciences, University of Tokyo, 3-8-1 Komaba, Meguro-ku, Tokyo, 153-8902 (Japan); Yoshida, M [Accelerator Laboratory, High Energy Accelerator Research Organization (KEK), 1-1 Oho, Tsukuba, Ibaraki, 305-0801 (Japan); Idehara, T; Ogawa, I; Kobayashi, S; Urushizaki, Y [Research Center for Development of Far-Infrared Region, University of Fukui (FIR-FU), 3-9-1 Bunkyo, Fukui, Fukui, 910-8507 (Japan); Sabchevski, S, E-mail: suehara@icepp.s.u-tokyo.ac.j [Bulgarian Academy of Science, 1, 15 Noemvri Str., 1040 Sofia (Bulgaria)

    2010-01-01

    Positronium is an ideal system for the research of the bound state QED. The hyperfine splitting of positronium (Ps-HFS: about 203 GHz) is sensitive to new physics beyond the Standard Model via a vacuum oscillation between an ortho-Ps and a virtual photon. Previous experimental results of the Ps-HFS show 3.9 {sigma} (15 ppm) discrepancy from the QED calculation. All previous experiments used an indirect method with static magnetic field to cause Zeeman splitting (a few GHz) between triplet states of ortho-Ps, from which the HFS value was derived. One possible systematic error source of the indirect method is the static magnetic field. We are developing a new direct measurement system of the Ps-HFS without static magnetic field. In this measurement we use a gyrotron, a novel sub-THz light source, with a high-finesse Fabry-Perot cavity to obtain enough radiation power at 203 GHz. The present status of the optimization studies and current design of the experiment are described.

  10. 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......B at the harddecision forward-error correction (HD-FEC) bit-error-rate (BER) limit 3.8 × 10□3 when multiplexing a Gaussian beam and OAM beams of azimuthal orders 1, 2 and 3 respectively. In case of phase modulation, power penalties do not exceed 1.77, 0.54 and 0.79 dB respectively. At the 0.4 nm wavelength grid......, 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...

  11. Temperature-independent fiber salinity sensor based on Fabry-Perot interference.

    Science.gov (United States)

    Zhang, Xinpu; Peng, Wei

    2015-04-20

    We present a novel fiber Fabry-Perot (FP) interference salinity sensor based on polyimide (PI) diaphragm. With an increase in water salinity, the PI diaphragm shrinks, and the PI diaphragm constriction causes the increase of the width of the air-gap, which causes the red shift of the interference fringes. We fabricated salinity sensor prototypes with different air-gap lengths and 20μm PI diaphragm. When salinity increases from 0mol/L to 5.47mol/L, the maximum sensitivity is 0.45nm/(mol/L). We verify that the sensitivity can be enhanced by reducing air-gap cavity length. We also choose appropriate air cavity length and PI diaphragm length to solve the cross-sensitivity between temperature and salinity. As a robust and ultra-compact salinity sensor, which is easy to be fabricated and need no alignment, this fiber interferometer can be applied for real-time salinity sensing applications.

  12. Evaluation of Fabry-Perot polymer film sensors made using hard dielectric mirror deposition

    Science.gov (United States)

    Buchmann, Jens; Zhang, Edward; Scharfenorth, Chris; Spannekrebs, Bastian; Villringer, Claus; Laufer, Jan

    2016-03-01

    Fabry-Perot (FP) polymer film sensors offer high acoustic sensitivity, small element sizes, broadband frequency response and optical transmission to enable high resolution, backward mode photoacoustic (PA) imaging. Typical approaches to sensor fabrication involve the deposition of stacks of alternating dielectric materials to form interferometer mirrors, which are separated by a polymer spacer. If hygroscopic soft dielectric materials are used, a protective polymer layer is typically required. In this study, methods for the deposition of water-resistant, hard dielectric materials onto polymers were explored to improve the robustness and performance of the sensors. This involved the optimisation of the fabrication process, the optical and acoustic characterisation of the sensors, and a comparison of the frequency response with the output of an acoustic forward model. The mirrors, which were separated by a 20 μm Parylene spacer, consisted of eight double layers of Ta2O5 and SiO2 deposited onto polymer substrates using temperature-optimised electron vapour deposition. The free spectral range of the interferometer was 32 nm, its finesse FR = 91, and its visibility V = 0.72. The noise-equivalent pressure was 0.3 kPa (20 MHz bandwidth). The measured frequency response was found to be more resonant at 25 MHz compared to sensors with soft dielectric mirrors, which was also in good agreement with the output of a forward model of the sensor. The sensors were used in a PA scanner to acquire 3-D images in tissue phantoms.

  13. 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.

  14. 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.

  15. Optical fiber extrinsic Fabry-Perot interferometric (EFPI)-based biosensors

    Science.gov (United States)

    Elster, Jennifer L.; Jones, Mark E.; Evans, Mishell K.; Lenahan, Shannon M.; Boyce, Christopher A.; Velander, William H.; VanTassell, Roger

    2000-05-01

    A novel system incorporating optical fiber extrinsic Fabry- Perot interferometric (EFPI)-based sensors for rapid detection of biological targets is presented. With the appropriate configuration, the EFPI senor is able to measure key environmental parameters by monitoring the interferometric fringes resulting from an optical path differences of reflected signals. The optical fiber EFPI sensor has been demonstrated for strain, pressure, and temperature measurements and can be readily modified for refractive index measurements by allowing solutions to flow into an open cavity. The sensor allows for highly sensitive, real-time, refractive index measurements and by applying affinity coatings containing ligands within this cavity, specific binding of target molecules can be accomplished. As target molecules bind to the coating, there is an increased density within the film, causing a measurable refractive index change that correlates to the concentration of detected target molecules. This sensor platform offers enhanced sensing capabilities for clinical diagnostics, pharmaceutical screening, environmental monitoring, food pathogen detection, biological warfare agent detection, and industrial bioprocessing. Promising applications also exist for process monitoring within the food/beverage, petroleum, and chemical industry.

  16. Fabry-Perot Microcavity Modes in Single GaP/GaNP Core/Shell Nanowires.

    Science.gov (United States)

    Dobrovolsky, Alexander; Stehr, Jan E; Sukrittanon, Supanee; Kuang, Yanjin; Tu, Charles W; Chen, Weimin M; Buyanova, Irina A

    2015-12-16

    Semiconductor nanowires (NWs) are attracting increasing interest as nanobuilding blocks for optoelectronics and photonics. A novel material system that is highly suitable for these applications are GaNP NWs. In this article, we show that individual GaP/GaNP core/shell nanowires (NWs) grown by molecular beam epitaxy on Si substrates can act as Fabry-Perot (FP) microcavities. This conclusion is based on results of microphotoluminescence (μ-PL) measurements performed on individual NWs, which reveal periodic undulations of the PL intensity that follow an expected pattern of FP cavity modes. The cavity is concluded to be formed along the NW axis with the end facets acting as reflecting mirrors. The formation of the FP modes is shown to be facilitated by an increasing index contrast with the surrounding media. Spectral dependence of the group refractive index is also determined for the studied NWs. The observation of the FP microcavity modes in the GaP/GaNP core/shell NWs can be considered as a first step toward achieving lasing in this quasidirect bandgap semiconductor in the NW geometry. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. 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.

  18. 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.

  19. High quality factor Er-doped Fabry-Perot microcavities by sol-gel processing

    Energy Technology Data Exchange (ETDEWEB)

    Li Yigang; Fortes, Luis M; Almeida, Rui M [Departamento de Engenharia de Materiais/ICEMS, Instituto Superior Tecnico/TULisbon, Av. Rovisco Pais, 1049-001 Lisboa (Portugal); Chiappini, Andrea; Ferrari, Maurizio, E-mail: yigang.li@ist.utl.p, E-mail: rui.almeida@ist.utl.p [CNR-IFN, Istituto di Fotonica e Nanotecnologie, CSMFO Lab., Via alla Cascata 56/C, Povo, 38123 Trento (Italy)

    2009-10-21

    An optimized sol-gel process was developed to fabricate 1D photonic bandgap structures. Several erbium-doped Fabry-Perot microcavities were prepared and characterized. The thickest sample contained two Bragg mirrors, each having 12 distributed Bragg reflector periods of alternating silicate glass and titania layers. The total thickness of this sample reached {approx}12 {mu}m. The Er{sup 3+} photoluminescence spectra at 1.5 {mu}m were measured for the microcavities. A quality factor of 250 and an Er{sup 3+} photoluminescence enhancement of 96 times at 1.5 {mu}m have been reached. The sol-gel processing details, the crystallization of the titania films and the refractive index of the deposited materials are discussed in detail. The simulated optical spectra of the microcavities were found to agree well with the actually measured curves. These results demonstrate that the present sol-gel processing technique is of potential interest for low cost fabrication of 1D photonic bandgap devices.

  20. Electrostatic actuated optical Fabry-Perot switches in passive matrix displays

    Science.gov (United States)

    Knieling, Thomas; Panitz, Meik; Benecke, Wolfgang

    2004-01-01

    In this paper a new approach for the realisation of a passive matrix image projection display consisting of electrostatic actuated Fabry-Perot filters for digital wavelength switching is presented. The switches either may be working by illumination with polychromatic or with monochromatic light, e.g. by a laser. In the first case the output light has to be filtered at the desired wavelength. In order to define the interferometric properties of the dielectric layers and thus the switching wavelength optical parameters like thickness and refractive index have to be adjusted carefully. The display switches can be adapted either to reflection or transmission mode, depending on whether silicon or quartz is used as substrate material. Especially hexagonal shaped pixel membranes for working either in reflection at a wavelength of 536 nm or in transmission for 500 nm are described. The assembly is arranged matrix-like in rows and columns, where at each intersection point a pixel is located. The switching of a pixel into the 'on'-state is achieved by applying a voltage on the corresponding row and column contact lines of the display. The resulting intersection potential deflects the addressed pixel membrane whereas adjacent pixels are nearly not affected. Actual measurements allow high switching frequencies of about 2 kHz at voltages in the range of 2 - 60 V, depending on the pixel design. The switching contrast maximum is aobut 80%, the contrast beteeen addressed and non-addressed adjacent pixels is 75%.

  1. Wide field of view spectroscopy using solid Fabry-Perot interferometers

    Science.gov (United States)

    Nikoleyczik, Jonathan; Kutyrev, Alexander; Moseley, Harvey; Veilleux, Sylvain

    2016-08-01

    We present a high resolution spectrometer consisting of dual solid Fabry-Perot Interferometers (FPI). Each FPI is made of a single piece of L-BBH2 glass which has a high index of refraction n 2.07. Each is then coated with partially reflective mirrors to achieve a spectral resolution of R 30,000. Running the FPIs in tandem reduces the overlapping orders and allows for a much wider free spectral range and higher contrast. Tuning of the FPIs is achieved by adjusting the temperature and thus changing the FPI gap and the refractive index of the material. The spectrometer then moves spatially in order to get spectral information at every point in the field of view. We select spectral lines for further analysis and create maps of the line depths across the field. Using this technique we are able to measure the fluorescence of chlorophyll in plants and observe zodiacal light. In the chlorophyll analysis we are able to detect chlorophyll fluorescence using the line depth in a plant using the sky as a reference solar spectrum. This instrument has possible applications in either a cubesat or aerial observations to measure bulk plant activity over large areas.

  2. Use of a Fabry Perot Interferometer to Isolate Pure Rotational Raman Spectra of Diatomic Molecules

    Science.gov (United States)

    Arshinov, Yuri; Bobrovnikov, Sergey

    1999-07-01

    We propose to use a Fabry Perot interferometer (FPI) as a comb frequency filter to isolate pure rotational Raman spectra (PRRS) of nitrogen molecules. In making the FPI s free spectral range equal to the spectral spacing between the lines of nitrogen PRRS, which are practically equidistant, one obtains a device with a comb transmission function with the same period. However, to match the FPI transmission comb completely with the comb of nitrogen PRRS lines one should tune the wavelength of the radiation used to excite the PRRS of nitrogen exactly to the position of any minimum in the FPI transmission comb. Thus to achieve this task for the case of nitrogen PRRS one must take the FPI s free spectral range f 4 B N 2 and the wavelength of the exciting radiation such that (1 exc ) 4 B N 2 ( k 1 2 ), where B N 2 is the rotational constant of the nitrogen molecule and k is an arbitrary integer number. In this case all (odd and even) pure rotational Raman lines of nitrogen will pass through the FPI while the line of exciting radiation is being suppressed. Additionally, a FPI cuts out the spectrally continuous sky background light from the spectral gaps between the PRRS lines.

  3. A Tiny Fabry-Perot Interferometer with Postpositional Filter for Measurement of the Thermospheric Wind

    Science.gov (United States)

    Wang, Houmao; Wang, Yongmei; Fu, Jianguo

    2016-12-01

    A tiny and low-cost ground-based Fabry-Perot interferometer (FPI) was designed using a filter behind etalon and Galilean telescope system for the thermospheric wind observation with OI 630.0 nm nightglow emissions ( 250 km). Based on the instrument, experiments were carried out at Langfang (39.40° N, 116.65° E) site for a rough comparison and Kelan (38.71° N, 111.58° E) site for a detailed validation. Wind results of Langfang experiment are well consistent with measurements of two other FPIs deployed at Xinglong (40.40° N, 117.59° E) and Kelan which are retrieved by the American National Center for Atmospheric Research (A-NCAR). In Kelan experiment, the averaged wind deviation between our FPI and A-NCAR FPI is 11.8 m/s. The averaged deviation of wind measurement error between them is 2.9 m/s. The comparisons suggest good agreement. Then, the analysis of influencing factors was made. The center determination offset has an exponential relation with wind deviation, while the radius calculation offset is linear with wind deviation.

  4. 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)

  5. 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.

  6. Large-aperture MOEMS Fabry-Perot interferometer for miniaturized spectral imagers

    Science.gov (United States)

    Rissanen, Anna; Langner, Andreas; Viherkanto, Kai; Mannila, Rami

    2015-02-01

    VTT's optical MEMS Fabry-Perot interferometers (FPIs) are tunable optical filters, which enable miniaturization of spectral imagers into small, mass producible hand-held sensors with versatile optical measurement capabilities. FPI technology has also created a basis for various hyperspectral imaging instruments, ranging from nanosatellites, environmental sensing and precision agriculture with UAVs to instruments for skin cancer detection. Until now, these application demonstrations have been mostly realized with piezo-actuated FPIs fabricated by non-monolithical assembly method, suitable for achieving very large optical apertures and with capacity to small-to-medium volumes; however large-volume production of MEMS manufacturing supports the potential for emerging spectral imaging applications also in large-volume applications, such as in consumer/mobile products. Previously reported optical apertures of MEMS FPIs in the visible range have been up to 2 mm in size; this paper presents the design, successful fabrication and characterization of MEMS FPIs for central wavelengths of λ = 500 nm and λ = 650 nm with optical apertures up to 4 mm in diameter. The mirror membranes of the FPI structures consist of ALD (atomic layer deposited) TiO2-Al2O3 λ/4- thin film Bragg reflectors, with the air gap formed by sacrificial polymer etching in O2 plasma. The entire fabrication process is conducted below 150 °C, which makes it possible to monolithically integrate the filter structures on other ICdevices such as detectors. The realized MEMS devices are aimed for nanosatellite space application as breadboard hyperspectral imager demonstrators.

  7. The effects of laser beam incident angle and intensity distribution on Fabry-Perot etalon spectrum

    Science.gov (United States)

    Shen, Fahua; Wang, Yingying; Shi, Wenjuan; Chen, Ying; Liu, Mengling; Guo, Wenxin

    2017-11-01

    Fabry-Perot(F-P) etalon has important applications in laser detection, lidar and laser communication systems. In practical applications, the spectrum of the F-P etalon is affected by various factors, such as incident angle, divergence angle, spectral width, intensity distribution of the incident beam, absorption loss, surface defects of the plate and so on. The effects of the incident angle and the beam intensity distribution on F-P etalon spectrum are mainly analyzed. For the first time, taking into account both the beam incident angle and divergence angle, the precise analytical expression of the F-P etalon transmission spectrum is derived. For the Gaussian light intensity distribution, the precise analytical expression of the F-P etalon transmission spectrum is derived. The simulation analysis is carried out and the results are as follows. When the beam divergence angle is not zero, the incident angle increases, on the one hand, the center of the etalon spectrum is moved to the high frequency, and the frequency shift is linear with the square of the incident angle. The slope decreases with the increase of the divergence angle. On the other hand, resulting in peak reduction, spectral line broadening, and with the divergence angle increases, the more obvious the phenomenon. Considering the distribution of Gaussian light intensity, the spectrum of the etalon will be improved with the increase concentration of beam energy. On the one hand, the peak value is increased, the spectral line is narrowed and with the incidence angle increases, the degree of improvement is more obvious. On the one hand, the center of the spectrum moves toward the low frequency, but the larger the incident angle, the smaller the movement amount. The error of frequency discrimination or frequency locking by using the F-P etalon spectrum increases rapidly with the increase of the beam incident angle and beam divergence angle, and the Gaussian light intensity distribution beam can effectively

  8. Daytime operation of a pure rotational Raman lidar by use of a Fabry-Perot interferometer

    Science.gov (United States)

    Arshinov, Yuri; Bobrovnikov, Sergey; Serikov, Ilya; Ansmann, Albert; Wandinger, Ulla; Althausen, Dietrich; Mattis, Ina; Müller, Detlef

    2005-06-01

    We propose to use a Fabry-Perot interferometer (FPI) in a pure rotational Raman lidar to isolate return signals that are due to pure rotational Raman scattering from atmospheric nitrogen against the sky background. The main idea of this instrumental approach is that a FPI is applied as a frequency comb filter with the transmission peaks accurately matched to a comb of practically equidistant lines of a pure rotational Raman spectrum (PRRS) of nitrogen molecules. Thus a matched FPI transmission comb cuts out the spectrally continuous sky background light from the spectral gaps between the PRRS lines of nitrogen molecules while it is transparent to light within narrow spectral intervals about these lines. As the width of the spectral gaps between the lines of the PRRS of nitrogen molecules is ~114 times the width of an individual spectral line, cutting out of the sky background from these gaps drastically improves the signal-to-background ratio of the pure rotational Raman lidar returns. This application of the FPI enables one to achieve daytime temperature profiling in the atmosphere with a pure rotational Raman lidar in the visible and near-UV spectral regions. We present an analysis of application of the FPI to filtering out the pure rotational Raman lidar returns against the solar background. To demonstrate the feasibility of the approach proposed, we present temperature profiles acquired during a whole-day measurement session in which a Raman lidar equipped with a FPI was used. For comparison, temperature profiles acquired with Vaisala radiosondes launched from the measurement site are also presented.

  9. Q-switching of a high-power solid-state laser by a fast scanning Fabry-Perot interferometer

    International Nuclear Information System (INIS)

    Baburin, N V; Borozdov, Yu V; Danileiko, Yu K; Denker, B I; Ivanov, A D; Osiko, Vyacheslav V; Sverchkov, S E; Sidorin, A V; Chikov, V A; Ifflander, R; Hack, R; Kertesz, I; Kroo, N

    1998-01-01

    An investigation was made of the suitability of a Q-switch, based on a piezoelectrically scanned short-base Fabry-Perot interferometer, for an Nd 3+ :YAG laser with an average output radiation power up to 2 kW. The proposed switch made it possible to generate of giant pulses of 60 - 300 ns duration at a repetition rate of 20 - 100 kHz. Throughout the investigated range of the pulse repetition rates the average power was at least equal to that obtained by cw lasing. Special requirements to be satisfied by the interferometer, essential for efficient Q-switching, were considered. (control of laser radiation parameters)

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

    OpenAIRE

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

    2017-01-01

    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 presen...

  11. Ferrule material dependence of axial force sensitivity of a tunable optical frequency filter made of fiber fabry-perot etalon

    Science.gov (United States)

    Tateda, Mitsuhiro; Dong, Mohan

    2011-01-01

    Fiber Fabry-Perot etalon (FFPE) is a device designed as an optical frequency filter, and its transmission characteristics change depending on force and temperature. In this paper, axial force sensitivity of three types of FFPE is investigated, whose ferrule materials have different Young's modulus. Force sensitivity of an FFPE whose ferrule material is borosilicate glass was found to be 2.7 GHz/N, while those of FFPEs with glass ceramics and zirconium oxide ferrules were 1.7 and 0.8 GHz/N, respectively. Thus, the theoretical expectation is confirmed experimentally that the axial force sensitivity of FFPE is inversely proportional to Young's modulus of the ferrule material.

  12. Mode power distribution effect in white-light multimode fiber extrinsic Fabry-Perot interferometric sensor systems.

    Science.gov (United States)

    Han, Ming; Wang, Anbo

    2006-05-01

    Theoretical and experimental results have shown that mode power distribution (MPD) variations could significantly vary the phase of spectral fringes from multimode fiber extrinsic Fabry-Perot interferometric (MMF-EFPI) sensor systems, owing to the fact that different modes introduce different extra phase shifts resulting from the coupling of modes reflected at the second surface to the lead-in fiber end. This dependence of fringe pattern on MPD could cause measurement errors in signal demodulation methods of white-light MMF-EFPI sensors that implement the phase information of the fringes.

  13. 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.

  14. Optical fiber sensor for electric field and electric charge using low-coherence, Fabry-Perot interferometry.

    Science.gov (United States)

    Priest, T S; Scelsi, G B; Woolsey, G A

    1997-07-01

    An optical fiber sensor for electric field and electric charge, based on the deflection of a small cantilever, has been developed. When the sensor head is placed in an electric field, induced charging produces deflection of the cantilever, which is measured using low-coherence, Fabry-Perot interferometry. The sensor has been used to measure the electric field in the vicinity of a Van de Graaff generator, in the range 135-650 V/cm. The measured deflections are in good agreement with the predictions of a simple model equating the electrostatic and mechanical forces acting on the cantilever.

  15. 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.

  16. 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

  17. SUNLITE program. Sub-Hertz relative frequency stabilization of two diode laser pumped Nd:YAG lasers locked to a Fabry-Perot interferometer

    Science.gov (United States)

    Byer, R. L.

    1990-01-01

    Two laser pumped Nd:YAG lasers were frequency stabilized to a commercial 6.327 GHz free spectral range Fabry-Perot interferometer yielding a best case beatnote linewidth of 330 MHz. In addition, a Fabry-Perot interferometer with a free spectral range of 680 MHz, a linewidth of 25 kHz, and a finesse of 27,500 was built, and when it was substituted in place of the commercial interferometer, it produced a robust and easily repeatable beatnote linewidth of 700 MHz.

  18. Sub-hertz relative frequency stabilization of two-diode laser-pumped Nd:YAG lasers locked to a Fabry-Perot interferometer

    Science.gov (United States)

    Day, Timothy; Gustafson, Eric K.; Byer, Robert L.

    1992-01-01

    Two-diode laser-pumped Nd:YAG lasers have been frequency stabilized to a commercial 6.327-GHz free spectral range Fabry-Perot interferometer yielding a best-case beatnote linewidth of 330 mHz. In addition, a Fabry-Perot interferometer with a free spectral range of 680 MHz, a linewidth of 25 kHz, and a finesse of 27,500 has been built, and when substituted in place of the commercial interferometer produced a robust and easily repeatable beatnote linewidth of 700 MHz.

  19. 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

  20. Airborne Doppler lidar at 532nm based on a tunable dual-channel Fabry-Perot interferometer

    Science.gov (United States)

    Feng, Jian-mei; Xing, Ting-wen; Lin, Wi-mei

    2009-07-01

    The aim of this paper is to explore a high-precision, a wide range of a frequency discrimination technique, and to study the application of this technique in the optical air data system (MOADS). To overcome the traditional equipment's shortcomings of short velocity detecting range such as pilot static tubes and wind wane, this technique can provide precision aviation data for various aerocrafts , without influencing pneumatic shape and performance of aerocraft. A tunable dual channel Fabry-Perot interferometer is used as a frequency discriminator in an airborne wind lidar system. This new frequency discriminator has been proposed to overcome the exiting frequency discriminator shortcoming. By adjusting the cavity length of interferometer, the speed of aerocraft can be detected and cut into several dynamic range. By this way, the Doppler wind lidar system can detect atmospheric parameters at the meantime, such as speed of aerocraft and temperature of atmosphere around the aerocraft, by analyzing the information of Rayleigh backscattering light. There are three main contribution in this paper: the first is discussing the basic theory of MOADS, calculational method and mathematic model of relative wind velocity between aircraft and wind are put forward.; the second is the parameter optimization of the dual-channel Fabry-Perot interferometer and the structure design of the interferometer; the third is the simulation of the performance and the accuracy of this system. Theory analysis and simulation results show this method is reasonable and practical.

  1. 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

  2. A tunable electrochromic fabry-perot filter for adaptive optics applications.

    Energy Technology Data Exchange (ETDEWEB)

    Blaich, Jonathan David; Kammler, Daniel R.; Ambrosini, Andrea; Sweatt, William C.; Verley, Jason C.; Heller, Edwin J.; Yelton, William Graham

    2006-10-01

    The potential for electrochromic (EC) materials to be incorporated into a Fabry-Perot (FP) filter to allow modest amounts of tuning was evaluated by both experimental methods and modeling. A combination of chemical vapor deposition (CVD), physical vapor deposition (PVD), and electrochemical methods was used to produce an ECFP film stack consisting of an EC WO{sub 3}/Ta{sub 2}O{sub 5}/NiO{sub x}H{sub y} film stack (with indium-tin-oxide electrodes) sandwiched between two Si{sub 3}N{sub 4}/SiO{sub 2} dielectric reflector stacks. A process to produce a NiO{sub x}H{sub y} charge storage layer that freed the EC stack from dependence on atmospheric humidity and allowed construction of this complex EC-FP stack was developed. The refractive index (n) and extinction coefficient (k) for each layer in the EC-FP film stack was measured between 300 and 1700 nm. A prototype EC-FP filter was produced that had a transmission at 500 nm of 36%, and a FWHM of 10 nm. A general modeling approach that takes into account the desired pass band location, pass band width, required transmission and EC optical constants in order to estimate the maximum tuning from an EC-FP filter was developed. Modeling shows that minor thickness changes in the prototype stack developed in this project should yield a filter with a transmission at 600 nm of 33% and a FWHM of 9.6 nm, which could be tuned to 598 nm with a FWHM of 12.1 nm and a transmission of 16%. Additional modeling shows that if the EC WO{sub 3} absorption centers were optimized, then a shift from 600 nm to 598 nm could be made with a FWHM of 11.3 nm and a transmission of 20%. If (at 600 nm) the FWHM is decreased to 1 nm and transmission maintained at a reasonable level (e.g. 30%), only fractions of a nm of tuning would be possible with the film stack considered in this study. These tradeoffs may improve at other wavelengths or with EC materials different than those considered here. Finally, based on our limited investigation and material set

  3. 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

  4. 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.

  5. A Theoretical Study and Numerical Simulation of a Quasi-Distributed Sensor Based on the Low-Finesse Fabry-Perot Interferometer: Frequency-Division Multiplexing.

    Science.gov (United States)

    Guillen Bonilla, José Trinidad; Guillen Bonilla, Alex; Rodríguez Betancourtt, Verónica M; Guillen Bonilla, Héctor; Casillas Zamora, Antonio

    2017-04-14

    The application of the sensor optical fibers in the areas of scientific instrumentation and industrial instrumentation is very attractive due to its numerous advantages. In the industry of civil engineering for example, quasi-distributed sensors made with optical fiber are used for reliable strain and temperature measurements. Here, a quasi-distributed sensor in the frequency domain is discussed. The sensor consists of a series of low-finesse Fabry-Perot interferometers where each Fabry-Perot interferometer acts as a local sensor. Fabry-Perot interferometers are formed by pairs of identical low reflective Bragg gratings imprinted in a single mode fiber. All interferometer sensors have different cavity length, provoking frequency-domain multiplexing. The optical signal represents the superposition of all interference patterns which can be decomposed using the Fourier transform. The frequency spectrum was analyzed and sensor's properties were defined. Following that, a quasi-distributed sensor was numerically simulated. Our sensor simulation considers sensor properties, signal processing, noise system, and instrumentation. The numerical results show the behavior of resolution vs. signal-to-noise ratio. From our results, the Fabry-Perot sensor has high resolution and low resolution. Both resolutions are conceivable because the Fourier Domain Phase Analysis (FDPA) algorithm elaborates two evaluations of Bragg wavelength shift.

  6. 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

  7. Wavelength modulation spectroscopy at 1530.32 nm for measurements of acetylene based on Fabry-Perot tunable filter

    Science.gov (United States)

    Yun-Long, Li; Bing-Chu, Yang; Xue-Mei, Xu

    2016-02-01

    Sensitive detection of acetylene (C2H2) is performed by absorption spectroscopy and wavelength modulation spectroscopy (WMS) based on Fiber Fabry-Perot tunable filter (FFP-TF) at 1530.32 nm. After being calibrated by Fiber Bragg Grating (FBG), FFP-TF is frequency-multiplexed and modulated at 20 Hz and 2.5 kHz respectively to achieve wavelength modulation. The linearity with 0.9907 fitting coefficient is obtained by measuring different concentrations in a 100 ppmv-400 ppmv range. Furthermore, the stability of the system is analyzed by detecting 50 ppmv and 100 ppmv standard gases for 2 h under room temperature and ambient pressure conditions respectively. The precision of 11 ppmv is achieved by calculating the standard deviation. Therefore, the measuring system of C2H2 detection can be applied in practical applications. Project supported by the National Natural Science Foundation of China (Grant Nos. 61172047 and 61071025).

  8. Large temperature sensitivity of fiber-optic extrinsic Fabry-Perot interferometer based on polymer-filled glass capillary

    Science.gov (United States)

    Zhang, Guilin; Yang, Minghong; Wang, Min

    2013-12-01

    A novel and low cost fiber-optic extrinsic Fabry-Perot interferometer (EFPI) is proposed. The EFPI is fabricated at the fiber tip by inserting a single mode fiber (SMF) into a partially polymer-filled glass capillary to form an air micro-cavity, which can be precisely controlled with a three-dimensional translation stage. The optimal EFPI has a loss less than 10 dB and a fringe visibility more than 30 dB. Application of the EFPI for temperature measurement is experimentally demonstrated. Due to the high thermal expansion coefficient (TEC) of the polymer, the sensor exhibits a good linear response and large temperature sensitivity of ˜5.2 nm/°C, which is almost three orders larger than that of the current F-P temperature sensors. Therefore, it may be applied to the surrounding temperature sensing.

  9. 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.

  10. SnO2-MOF-Fabry-Perot humidity optical sensor system based on fast Fourier transform technique

    Science.gov (United States)

    Lopez-Aldaba, A.; Lopez-Torres, D.; Ascorbe, J.; Rota-Rodrigo, S.; Elosua, C.; Lopez-Amo, M.; Arregui, F. J.; Corres, J. M.; Auguste, J.-L.; Jamier, R.; Roy, P.

    2016-05-01

    In this paper, a new sensor system for relative humidity measurements based on a SnO2 sputtering deposition on a microstructured optical fiber (MOF) low-finesse Fabry-Perot (FP) sensing head is presented and characterized. The interrogation of the sensing head is carried out by monitoring the Fast Fourier Transform phase variations of the FP interference frequency. This method is low-sensitive to signal amplitude variations and also avoids the necessity of tracking the evolution of peaks and valleys in the spectrum. The sensor is operated within a wide humidity range (20%-90% relative humidity) with a maximum sensitivity achieved of 0.14rad/%. The measurement method uses a commercial optical interrogator as the only active element, this compact solution allows real time analysis of the data.

  11. 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.

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

    Directory of Open Access Journals (Sweden)

    Qiangzhou Rong

    2017-02-01

    Full Text Available 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.

  13. Large field enhancement obtained by combining Fabry-Perot resonance and Rayleigh anomaly in photonic crystal slabs

    Science.gov (United States)

    Dossou, Kokou B.

    2017-04-01

    By applying the properties of Fabry-Perot resonance and Rayleigh anomaly, we have shown that a photonic crystal slab can scatter the light from an incident plane wave into a diffracted light with a very large reflection or transmission coefficient. The enhanced field is either a propagating diffracted wave (with a grazing angle of diffraction) or a weakly evanescent diffracted wave, so it can be particularly useful for applications requiring an enhanced propagating field (or an enhanced field with a low attenuation). An efficient effective medium technique is developed for the design of the resonant photonic crystal slabs. Numerical simulations have shown that photonic crystal slabs with low index contrast, such as the ones found in the cell wall of diatoms, can enhance the intensity of the incident light by four orders of magnitude.

  14. Quantum-enhanced metrology based on Fabry-Perot interferometer by squeezed vacuum and non-Gaussian detection

    Energy Technology Data Exchange (ETDEWEB)

    Li, Wenfang; Du, Jinjin; Wen, Ruijuan; Li, Gang; Zhang, Tiancai, E-mail: tczhang@sxu.edu.cn [State Key Laboratory of Quantum Optics and Quantum Optics Devices, Institute of Opto-Electronics, Shanxi University, Taiyuan 030006 (China)

    2014-03-28

    We have investigated the transmission spectra of a Fabry-Perot interferometer (FPI) with squeezed vacuum state injection and non-Gaussian detection, including photon number resolving detection and parity detection. In order to show the suitability of the system, parallel studies were made of the performance of two other light sources: coherent state of light and Fock state of light either with classical mean intensity detection or with non-Gaussian detection. This shows that by using the squeezed vacuum state and non-Gaussian detection simultaneously, the resolution of the FPI can go far beyond the cavity standard bandwidth limit based on the current techniques. The sensitivity of the scheme has also been explored and it shows that the minimum detectable sensitivity is better than that of the other schemes.

  15. 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.

  16. Impact of mode partition noise in free-running gain-switched Fabry-Perot laser for 2-dimensional OCDMA.

    Science.gov (United States)

    Wang, Xu; Chan, Kam

    2004-07-26

    Free-running gain-switched Fabry-Perot laser diode is an appropriate incoherent broadband optical source for incoherent 2-dimensional optical code division multiple access. However, the mode partition noise (MPN) in the laser seriously degrades performance. We derived a bit error rate (BER) expression in the presence of MPN using the power spectra of the laser. The theory agreed with the experimental results. There was a power penalty and BER floor due to the MPN in the laser. Therefore, this scheme should be operated with a sufficiently large number of modes. At least 9 modes should be used for error-free transmission at 1 Gbit/s for the laser we investigated in this work.

  17. 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

  18. 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

  19. 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)

  20. Watt-level widely tunable single-mode emission by injection-locking of a multimode Fabry-Perot quantum cascade laser

    Science.gov (United States)

    Chevalier, Paul; Piccardo, Marco; Anand, Sajant; Mejia, Enrique A.; Wang, Yongrui; Mansuripur, Tobias S.; Xie, Feng; Lascola, Kevin; Belyanin, Alexey; Capasso, Federico

    2018-02-01

    Free-running Fabry-Perot lasers normally operate in a single-mode regime until the pumping current is increased beyond the single-mode instability threshold, above which they evolve into a multimode state. As a result of this instability, the single-mode operation of these lasers is typically constrained to few percents of their output power range, this being an undesired limitation in spectroscopy applications. In order to expand the span of single-mode operation, we use an optical injection seed generated by an external-cavity single-mode laser source to force the Fabry-Perot quantum cascade laser into a single-mode state in the high current range, where it would otherwise operate in a multimode regime. Utilizing this approach, we achieve single-mode emission at room temperature with a tuning range of 36 cm-1 and stable continuous-wave output power exceeding 1 W at 4.5 μm. Far-field measurements show that a single transverse mode is emitted up to the highest optical power, indicating that the beam properties of the seeded Fabry-Perot laser remain unchanged as compared to free-running operation.

  1. HCPCF-based in-line fiber Fabry-Perot refractometer and high sensitivity signal processing method

    Science.gov (United States)

    Liu, Xiaohui; Jiang, Mingshun; Sui, Qingmei; Geng, Xiangyi; Song, Furong

    2017-12-01

    An in-line fiber Fabry-Perot interferometer (FPI) based on the hollow-core photonic crystal fiber (HCPCF) for refractive index (RI) measurement is proposed in this paper. The FPI is formed by splicing both ends of a short section of the HCPCF to single mode fibers (SMFs) and cleaving the SMF pigtail to a proper length. The RI response of the sensor is analyzed theoretically and demonstrated experimentally. The results show that the FPI sensor has linear response to external RI and good repeatability. The sensitivity calculated from the maximum fringe contrast is -136 dB/RIU. A new spectrum differential integration (SDI) method for signal processing is also presented in this study. In this method, the RI is obtained from the integrated intensity of the absolute difference between the interference spectrum and its smoothed spectrum. The results show that the sensitivity obtained from the integrated intensity is about -1.34×105 dB/RIU. Compared with the maximum fringe contrast method, the new SDI method can provide the higher sensitivity, better linearity, improved reliability, and accuracy, and it's also convenient for automatic and fast signal processing in real-time monitoring of RI.

  2. Diaphragm-Free Fiber-Optic Fabry-Perot Interferometric Gas Pressure Sensor for High Temperature Application

    Directory of Open Access Journals (Sweden)

    Hao Liang

    2018-03-01

    Full Text Available A diaphragm-free fiber-optic Fabry-Perot (FP interferometric gas pressure sensor is designed and experimentally verified in this paper. The FP cavity was fabricated by inserting a well-cut fiber Bragg grating (FBG and hollow silica tube (HST from both sides into a silica casing. The FP cavity length between the ends of the SMF and HST changes with the gas density. Using temperature decoupling method to improve the accuracy of the pressure sensor in high temperature environments. An experimental system for measuring the pressure under different temperatures was established to verify the performance of the sensor. The pressure sensitivity of the FP gas pressure sensor is 4.28 nm/MPa with a high linear pressure response over the range of 0.1–0.7 MPa, and the temperature sensitivity is 14.8 pm/°C under the range of 20–800 °C. The sensor has less than 1.5% non-linearity at different temperatures by using temperature decoupling method. The simple fabrication and low-cost will help sensor to maintain the excellent features required by pressure measurement in high temperature applications.

  3. High-sensitivity and large-dynamic-range refractive index sensors employing weak composite Fabry-Perot cavities.

    Science.gov (United States)

    Chen, Pengcheng; Shu, Xuewen; Cao, Haoran; Sugden, Kate

    2017-08-15

    Most sensors face a common trade-off between high sensitivity and a large dynamic range. We demonstrate here an all-fiber refractometer based on a dual-cavity Fabry-Perot interferometer (FPI) that possesses the advantage of both high sensitivity and a large dynamic range. Since the two composite cavities have a large cavity length difference, one can observe both fine and coarse fringes, which correspond to the long cavity and the short cavity, respectively. The short-cavity FPI and the use of an intensity demodulation method mean that the individual fine fringe dips correspond to a series of quasi-continuous highly sensitive zones for refractive index measurement. By calculating the parameters of the composite FPI, we find that the range of the ultra-sensitive zones can be considerably adjusted to suit the end requirements. The experimental trends are in good agreement with the theoretical predictions. The co-existence of high sensitivity and a large dynamic range in a composite FPI is of great significance to practical RI measurements.

  4. A simple fiber-optic humidity sensor based on extrinsic Fabry-Perot cavity constructed by cellulose acetate butyrate film

    Science.gov (United States)

    Xu, Wei; Huang, Wo-Bin; Huang, Xu-Guang; Yu, Chang-yuan

    2013-12-01

    A fiber-optic relative humidity sensor with an extrinsic micro Fabry-Perot cavity constructed with a thin layer of cellulose acetate butyrate coated on a fiber end is presented. Its operational principle is based on the relative-humidity-dependent wavelength shift of the interference fringes formed by Fresnel reflections from both interfaces of the thin film. Both the experimental and theoretical analyses are investigated in detail. The experimental data for relative humidity ranging from 8.8% to 88.1% are measured in the both humidification and dehumidification processes, which fits the linear equation very well with a value of R2 = 0.9946. As observed, it shows a high sensitivity of 0.307 nm/%RH with a high resolution of 0.06%. The time-dependent response of the sensor is estimated. The long term stability of the sensor is also addressed with high precision of ±0.03% over 100 min. The proposed relative humidity sensor has a simple, solid, and compact structure.

  5. Measurements of Thermospheric Winds and Temperatures with a Fabry-Perot Interferometer Network: Results from NATION, South America, and Alaska

    Science.gov (United States)

    Meriwether, J. W.; Makela, J. J.; Ridley, A. J.

    2014-12-01

    Results in recent years have demonstrated that studies of thermospheric dynamics over small or large spatial scales are enhanced when measurements of the wind and temperature fields are obtained as a part of a network of Fabry-Perot interferometers (FPI). In contrast to the all-sky FPI design used in the polar region by Conde and colleagues, these FPIs are narrow-field instruments that utilize a SkyScanner to observe in a series of directions over a region 500-800 km in diameter. The sensitivity of these instruments has increased dramatically over older FPIs, allowing new and interesting phenomena to be investigated. When two or more FPIs are utilized, different observing strategies may then offer advantages regarding the ability to study the thermospheric-ionosphere system response over small and large scale sizes that can not be achieved by a single FPI observatory. Examples of results obtained by the North American Thermospheric and Ionospheric Observing Network (NATION), the five FPIs operating in South America, and the three FPIs observing in Alaska will illustrate the system science advantages provided by such networks.

  6. 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.

  7. 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.

  8. 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

  9. Enhanced green fluorescent protein in optofluidic Fabry-Perot microcavity to detect laser induced temperature changes in a bacterial culture

    Science.gov (United States)

    Lahoz, F.; Martín, I. R.; Walo, D.; Freire, R.; Gil-Rostra, J.; Yubero, F.; Gonzalez-Elipe, A. R.

    2017-09-01

    Thermal therapy using laser sources can be used in combination with other cancer therapies to eliminate tumors. However, high precision temperature control is required to avoid damage in healthy surrounding tissues. Therefore, in order to detect laser induced temperature changes, we have used the fluorescence signal of the enhanced Green Fluorescent Protein (eGFP) over-expressed in an E. coli bacterial culture. For that purpose, the bacteria expressing eGFP are injected in a Fabry-Perot (FP) optofluidic planar microcavity. In order to locally heat the bacterial culture, external infrared or ultraviolet lasers were used. Shifts in the wavelengths of the resonant FP modes are used to determine the temperature increase as a function of the heating laser pump power. Laser induced local temperature increments up to 6-7 °C were measured. These results show a relatively easy way to measure laser induced local temperature changes using a FP microcavity and using eGFP as a molecular probe instead of external nanoparticles, which could damage/alter the cell. Therefore, we believe that this approach can be of interest for the study of thermal effects in laser induced thermal therapies.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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

    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 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.

  16. Diaphragm-Free Fiber-Optic Fabry-Perot Interferometric Gas Pressure Sensor for High Temperature Application.

    Science.gov (United States)

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

    2018-03-28

    A diaphragm-free fiber-optic Fabry-Perot (FP) interferometric gas pressure sensor is designed and experimentally verified in this paper. The FP cavity was fabricated by inserting a well-cut fiber Bragg grating (FBG) and hollow silica tube (HST) from both sides into a silica casing. The FP cavity length between the ends of the SMF and HST changes with the gas density. Using temperature decoupling method to improve the accuracy of the pressure sensor in high temperature environments. An experimental system for measuring the pressure under different temperatures was established to verify the performance of the sensor. The pressure sensitivity of the FP gas pressure sensor is 4.28 nm/MPa with a high linear pressure response over the range of 0.1-0.7 MPa, and the temperature sensitivity is 14.8 pm/°C under the range of 20-800 °C. The sensor has less than 1.5% non-linearity at different temperatures by using temperature decoupling method. The simple fabrication and low-cost will help sensor to maintain the excellent features required by pressure measurement in high temperature applications.

  17. 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.

  18. Vacuum ultraviolet photoionization of carbohydrates and nucleotides

    International Nuclear Information System (INIS)

    Shin, Joong-Won; Bernstein, Elliot R.

    2014-01-01

    Carbohydrates (2-deoxyribose, ribose, and xylose) and nucleotides (adenosine-, cytidine-, guanosine-, and uridine-5 ′ -monophosphate) are generated in the gas phase, and ionized with vacuum ultraviolet photons (VUV, 118.2 nm). The observed time of flight mass spectra of the carbohydrate fragmentation are similar to those observed [J.-W. Shin, F. Dong, M. Grisham, J. J. Rocca, and E. R. Bernstein, Chem. Phys. Lett. 506, 161 (2011)] for 46.9 nm photon ionization, but with more intensity in higher mass fragment ions. The tendency of carbohydrate ions to fragment extensively following ionization seemingly suggests that nucleic acids might undergo radiation damage as a result of carbohydrate, rather than nucleobase fragmentation. VUV photoionization of nucleotides (monophosphate-carbohydrate-nucleobase), however, shows that the carbohydrate-nucleobase bond is the primary fragmentation site for these species. Density functional theory (DFT) calculations indicate that the removed carbohydrate electrons by the 118.2 nm photons are associated with endocyclic C–C and C–O ring centered orbitals: loss of electron density in the ring bonds of the nascent ion can thus account for the observed fragmentation patterns following carbohydrate ionization. DFT calculations also indicate that electrons removed from nucleotides under these same conditions are associated with orbitals involved with the nucleobase-saccharide linkage electron density. The calculations give a general mechanism and explanation of the experimental results

  19. Vacuum ultraviolet photoionization of carbohydrates and nucleotides

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Joong-Won, E-mail: jshin@govst.edu [Division of Science, Governors State University, University Park, Illinois 60484-0975 (United States); Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523-1872 (United States); Bernstein, Elliot R., E-mail: erb@lamar.colostate.edu [Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523-1872 (United States)

    2014-01-28

    Carbohydrates (2-deoxyribose, ribose, and xylose) and nucleotides (adenosine-, cytidine-, guanosine-, and uridine-5{sup ′}-monophosphate) are generated in the gas phase, and ionized with vacuum ultraviolet photons (VUV, 118.2 nm). The observed time of flight mass spectra of the carbohydrate fragmentation are similar to those observed [J.-W. Shin, F. Dong, M. Grisham, J. J. Rocca, and E. R. Bernstein, Chem. Phys. Lett. 506, 161 (2011)] for 46.9 nm photon ionization, but with more intensity in higher mass fragment ions. The tendency of carbohydrate ions to fragment extensively following ionization seemingly suggests that nucleic acids might undergo radiation damage as a result of carbohydrate, rather than nucleobase fragmentation. VUV photoionization of nucleotides (monophosphate-carbohydrate-nucleobase), however, shows that the carbohydrate-nucleobase bond is the primary fragmentation site for these species. Density functional theory (DFT) calculations indicate that the removed carbohydrate electrons by the 118.2 nm photons are associated with endocyclic C–C and C–O ring centered orbitals: loss of electron density in the ring bonds of the nascent ion can thus account for the observed fragmentation patterns following carbohydrate ionization. DFT calculations also indicate that electrons removed from nucleotides under these same conditions are associated with orbitals involved with the nucleobase-saccharide linkage electron density. The calculations give a general mechanism and explanation of the experimental results.

  20. Vacuum ultraviolet photoionization of carbohydrates and nucleotides

    Science.gov (United States)

    Shin, Joong-Won; Bernstein, Elliot R.

    2014-01-01

    Carbohydrates (2-deoxyribose, ribose, and xylose) and nucleotides (adenosine-, cytidine-, guanosine-, and uridine-5'-monophosphate) are generated in the gas phase, and ionized with vacuum ultraviolet photons (VUV, 118.2 nm). The observed time of flight mass spectra of the carbohydrate fragmentation are similar to those observed [J.-W. Shin, F. Dong, M. Grisham, J. J. Rocca, and E. R. Bernstein, Chem. Phys. Lett. 506, 161 (2011)] for 46.9 nm photon ionization, but with more intensity in higher mass fragment ions. The tendency of carbohydrate ions to fragment extensively following ionization seemingly suggests that nucleic acids might undergo radiation damage as a result of carbohydrate, rather than nucleobase fragmentation. VUV photoionization of nucleotides (monophosphate-carbohydrate-nucleobase), however, shows that the carbohydrate-nucleobase bond is the primary fragmentation site for these species. Density functional theory (DFT) calculations indicate that the removed carbohydrate electrons by the 118.2 nm photons are associated with endocyclic C-C and C-O ring centered orbitals: loss of electron density in the ring bonds of the nascent ion can thus account for the observed fragmentation patterns following carbohydrate ionization. DFT calculations also indicate that electrons removed from nucleotides under these same conditions are associated with orbitals involved with the nucleobase-saccharide linkage electron density. The calculations give a general mechanism and explanation of the experimental results.

  1. Vacuum ultraviolet detector for gas chromatography.

    Science.gov (United States)

    Schug, Kevin A; Sawicki, Ian; Carlton, Doug D; Fan, Hui; McNair, Harold M; Nimmo, John P; Kroll, Peter; Smuts, Jonathan; Walsh, Phillip; Harrison, Dale

    2014-08-19

    Analytical performance characteristics of a new vacuum ultraviolet (VUV) detector for gas chromatography (GC) are reported. GC-VUV was applied to hydrocarbons, fixed gases, polyaromatic hydrocarbons, fatty acids, pesticides, drugs, and estrogens. Applications were chosen to feature the sensitivity and universal detection capabilities of the VUV detector, especially for cases where mass spectrometry performance has been limited. Virtually all chemical species absorb and have unique gas phase absorption cross sections in the approximately 120-240 nm wavelength range monitored. Spectra are presented, along with the ability to use software for deconvolution of overlapping signals. Some comparisons with experimental synchrotron data and computed theoretical spectra show good agreement, although more work is needed on appropriate computational methods to match the simultaneous broadband electronic and vibronic excitation initiated by the deuterium lamp. Quantitative analysis is governed by Beer-Lambert Law relationships. Mass on-column detection limits reported for representatives of different classes of analytes ranged from 15 (benzene) to 246 pg (water). Linear range measured at peak absorption for benzene was 3-4 orders of magnitude. Importantly, where absorption cross sections are known for analytes, the VUV detector is capable of absolute determination (without calibration) of the number of molecules present in the flow cell in the absence of chemical interferences. This study sets the stage for application of GC-VUV technology across a wide breadth of research areas.

  2. Thermospheric gravity waves in Fabry-Perot Interferometer measurements of the 630.0nm OI line

    Directory of Open Access Journals (Sweden)

    E. A. K. Ford

    2006-03-01

    Full Text Available 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. It is known that some gravity waves may propagate through the mesopause and reach greater altitudes before eventually "breaking" and depositing energy. The generation, propagation, and breaking of upper thermospheric gravity waves have not been studied directly often. However, their ionospheric counterparts, travelling ionospheric disturbances (TIDs, have been extensively studied in, for example, radar data. At high latitudes, it is believed localised auroral activity may generate gravity waves in-situ. Increases in sensor efficiency of Fabry-Perot Interferometers (FPIs located in northern Scandinavia have provided higher time resolution measurements of the auroral oval and polar cap atomic oxygen red line emission at 630.0 nm. A Lomb-Scargle analysis of this data has shown evidence of gravity wave activity with periods ranging from a few tens of minutes to several hours. Oscillations are seen in the intensity of the line as well as the temperatures and line of sight winds. Instruments are located in Sodankylä, Finland; Kiruna, Sweden; Skibotn, Norway, and Svalbard in the Arctic Ocean. A case study is presented here, where a wave of 1.8 h period has a phase speed of 250 ms-1 with a propagation angle of 302°, and a horizontal wavelength of 1600 km. All the FPIs are co-located with EISCAT radars, as well as being supplemented by a range of other instrumentation. This allows the waves found in the FPI data to be put in context with the ionosphere and atmosphere system. Consequently, the source region of the gravity waves can be determined.

  3. Thermospheric gravity waves in Fabry-Perot Interferometer measurements of the 630.0nm OI line

    Directory of Open Access Journals (Sweden)

    E. A. K. Ford

    2006-03-01

    Full Text Available 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. It is known that some gravity waves may propagate through the mesopause and reach greater altitudes before eventually "breaking" and depositing energy. The generation, propagation, and breaking of upper thermospheric gravity waves have not been studied directly often. However, their ionospheric counterparts, travelling ionospheric disturbances (TIDs, have been extensively studied in, for example, radar data. At high latitudes, it is believed localised auroral activity may generate gravity waves in-situ. Increases in sensor efficiency of Fabry-Perot Interferometers (FPIs located in northern Scandinavia have provided higher time resolution measurements of the auroral oval and polar cap atomic oxygen red line emission at 630.0 nm. A Lomb-Scargle analysis of this data has shown evidence of gravity wave activity with periods ranging from a few tens of minutes to several hours. Oscillations are seen in the intensity of the line as well as the temperatures and line of sight winds. Instruments are located in Sodankylä, Finland; Kiruna, Sweden; Skibotn, Norway, and Svalbard in the Arctic Ocean. A case study is presented here, where a wave of 1.8 h period has a phase speed of 250 ms-1 with a propagation angle of 302°, and a horizontal wavelength of 1600 km. All the FPIs are co-located with EISCAT radars, as well as being supplemented by a range of other instrumentation. This allows the waves found in the FPI data to be put in context with the ionosphere and atmosphere system. Consequently, the source region of the gravity waves can be determined.

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

    Science.gov (United States)

    Li, Cheng; Lan, Tian; Yu, Xiyu; Bo, Nan; Dong, Jingyu; Fan, Shangchun

    2017-11-04

    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.

  5. 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.

  6. 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.

  7. Commissioning MOS and Fabry-Perot modes for the Robert Stobie Spectrograph on the Southern African Large Telescope

    Science.gov (United States)

    Koeslag, A. R.; Williams, T. B.; Nordsieck, K. H.; Romero-Colmenero, E.; Vaisanen, P. H.; Maartens, D. S.

    2014-07-01

    The Southern African Large Telescope (SALT) currently has three instruments: the imaging SALTICAM, the new High Resolution Spectrograph (HRS) which is in the process of being commissioned and the Robert Stobie Spectrograph (RSS). RSS has multiple science modes, of which long slit spectroscopy was originally commissioned; We have commissioned two new science modes: Multi Object Spectroscopy (MOS) and Fabry-Perot (FP). Due to the short track times available on SALT it is vital that acquisition is as efficient as possible. This paper will discuss how we implemented these modes in software and some of the challenges we had to overcome. MOS requires a slit-mask to be aligned with a number of stars. This is done in two phases: in MOS calibration the positions of the slits are detected using a through-slit image and RA/DEC database information, and in MOS acquisition the detector sends commands to the telescope control system (TCS) in an iterative and interactive fashion for fine mask/detector alignment to get the desired targets on the slits. There were several challenges involved with this system, and the user interface evolved to make the process as efficient as possible. We also had to overcome problems with the manufacturing process of the slit-masks. FP requires the precise alignment each of the two etalons installed on RSS. The software makes use of calibration tables to get the etalons into roughly aligned starting positions. An exposure is then done using a calibration arc lamp, producing a ring pattern. Measurement of the rings allows the determination of the adjustments needed to properly align the etalons. The software has been developed to optimize this process, along with software tools that allow us to fine tune the calibration tables. The software architecture allows the complexity of automating the FP calibration and procedures to be easily managed.

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

    International Nuclear Information System (INIS)

    Aguayo-Rodriguez, G; Zaldivar-Huerta, I E; GarcIa-Juarez, A; Rodriguez-Asomoza, J; Larger, L; Courjal, N

    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.

  9. 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.

  10. Vacuum Ultraviolet Laser Probe of Chemical Dynamics of Aerospace Relevance

    Science.gov (United States)

    2012-09-12

    RESPONSIBLE PERSON 19b. TELEPHONE NUMBER (Include area code) 09/12/12 01/15/09-11/30/11 VACUUM ULTRAVIOLET LASER PROBES OF CHEMICAL DYNAMICS PF...is to be limited. Standard Form 298 Back (Rev. 8/98) FINAL AFOSR REPORT (Dec. 1, 2008-Nov. 30, 2011) I. Grant Title: Vacuum Ultraviolet ...goal of this research program is to provide pertinent information about the energetics, photochemistry , and chemical dynamics of spacecraft effluents

  11. Rapid volumetric photoacoustic tomographic imaging with a Fabry-Perot ultrasound sensor depicts peripheral arteries and microvascular vasomotor responses to thermal stimuli.

    Science.gov (United States)

    Plumb, Andrew A; Huynh, Nam Trung; Guggenheim, Jamie; Zhang, Edward; Beard, Paul

    2018-03-01

    To determine if a new photoacoustic imaging (PAI) system successfully depicts (1) peripheral arteries and (2) microvascular circulatory changes in response to thermal stimuli. Following ethical permission, 8 consenting subjects underwent PAI of the dorsalis pedis (DP) artery, and 13 completed PAI of the index fingertip. Finger images were obtained after immersion in warm (30-35 °C) or cold (10-15 °C) water to promote vasodilation or vasoconstriction. The PAI instrument used a Fabry-Perot interferometeric ultrasound sensor and a 30-Hz 750-nm pulsed excitation laser. Volumetric images were acquired through a 14 × 14 × 14-mm volume over 90 s. Images were evaluated subjectively and quantitatively to determine if PAI could depict cold-induced vasoconstriction. The full width at half maximum (FWHM) of resolvable vessels was measured. Fingertip vessels were visible in all participants, with mean FWHM of 125 μm. Two radiologists used PAI to correctly identify vasoconstricted fingertip capillary beds with 100% accuracy (95% CI 77.2-100.0%, p thermal stimuli. • Fabry-Perot interferometer-based photoacoustic imaging (PAI) generates volumetric, high-resolution images of the peripheral vasculature. • The system reliably detects thermally induced peripheral vasoconstriction (100% correct identification rate, p < 0.001). • Vessels measuring less than 100 μm in diameter can be depicted in vivo.

  12. 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.

  13. Submillimeter spectroscopy of the Carina Nebula: Observations, operations and upgrades of the South Pole Imaging Fabry-Perot Interferometer

    Science.gov (United States)

    Oberst, Thomas Edward

    2009-06-01

    We present the results of a ~ 250 arcmin 2 mapping of the 205 μm [NII] fine- structure line emission over the northern Carina Nebula, including the Car I and Car II HII regions. Spectra were obtained using the South Pole Imaging Fabry-Perot Interferometer (SPIFI) at the Antarctic Telescope and Remote Observatory (AST/RO) at South Pole. New upgrades and modifications to the SPIFI instrument are discussed, and full details of SPIFI-AST/RO integration and calibration are provided. At the time of these observations, SPIFI had a spectral resolving power of ~ 4250, a FWHM beam size of ~ 54'', and a noise equivalent power (NEP) referred to the front end of the receiver of ~ 2.5 × 10 -15 W Hz -1/2 (~ 1.4 times the background limit). These data constitute the first ground-based detection of the 205 μm [NII] line, and only the third detection overall since those of the Cosmic Background Explorer (COBE) Far Infrared Absolute Spectrophotometer (FIRAS) and the Kuiper Airborne Observatory (KAO) in the early 1990s. We supplement the 205 μm data with new reductions of far-infrared fine- structure spectra from the Infrared Space Observatory (ISO) in 63 μm [OI], 122 m [NII], 146 μm [OI], and 158 μm [CII]; the 146 μm [OI] data include 90 raster positions which have not been previously published. Morphological comparisons are made with optical, radio continuum and CO maps. The 122/205 [NII] line ratio is used to probe the density of the low-ionization gas, and the 158/205 [CII]/[NII] line ratio is used to probe the fraction of C + arising from photodissociation regions (PDRs). The [OI] and [CII] lines are used to construct a PDR model of Carina following Kaufman et al. (1999). When the PDR properties are compared with other sources, Carina is found to be more akin to 30 Doradus than galactic star-forming regions such as Orion, M17, or W49. This is consistent with the view of Carina as a more evolved region, where much of the parent molecular cloud has been ionized or swept

  14. 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

  15. Jones matrix description of Fabry-Perot interference in a single axis photo-elastic modulator and the consequences for the magneto-optical measurement method

    Science.gov (United States)

    Talukder, Md. Abdul Ahad; Geerts, Wilhelmus J.

    2017-08-01

    When using a Photo-elastic modulator (PEM) in combination with a coherent light source, in addition to the modulation of the phase, Fabry-Perot interference in the PEM's optical head induces large offsets in the 1ω and 2ω detector signals. A Jones matrix which describes both effects simultaneously, was derived for a single axis PEM and used to find an expression for the detector signal for two different MO Kerr setups. The effect of the PEM tilt angle, polarizer angle, analyzer angle, and retardation, on the detector signal offsets show that offsets can be zeroed by adjusting PEM tilt angle, polarizer angle, and retardation. This strategy will allow one to avoid large offset drifts due to the small retardation, intensity, and beam direction fluctuations caused by lab temperature fluctuations. In addition, it will enable one to measure in the most sensitive range of the lock-in amplifiers further improving the signal to noise ratio of the setup.

  16. A New Remote Sensing Filter Radiometer Employing a Fabry-Perot Etalon and a CCD Camera for Column Measurements of Methane in the Earth Atmosphere

    Science.gov (United States)

    Georgieva, E. M.; Huang, W.; Heaps, W. S.

    2012-01-01

    A portable remote sensing system for precision column measurements of methane has been developed, built and tested at NASA GSFC. The sensor covers the spectral range from 1.636 micrometers to 1.646 micrometers, employs an air-gapped Fabry-Perot filter and a CCD camera and has a potential to operate from a variety of platforms. The detector is an XS-1.7-320 camera unit from Xenics Infrared solutions which combines an uncooled InGaAs detector array working up to 1.7 micrometers. Custom software was developed in addition to the graphical user basic interface X-Control provided by the company to help save and process the data. The technique and setup can be used to measure other trace gases in the atmosphere with minimal changes of the etalon and the prefilter. In this paper we describe the calibration of the system using several different approaches.

  17. 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.

  18. 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.

  19. 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.

  20. A wavelength tunable ONU transmitter based on multi-mode Fabry-Perot laser and micro-ring resonator for bandwidth symmetric TWDM-PON

    Science.gov (United States)

    Gao, Zhensen; Sun, Xiao; Zhang, Kaibin

    2016-02-01

    Wavelength tunable optical transmitter is an essential component for the newly standardized time and wavelength division multiplexed passive optical network (TWDM-PON), where tunable ONU with 10Gb/s bit rate is desired to provide 40Gb/s symmetric bandwidth. In this paper, a novel wavelength tunable optical transmitter is proposed by reusing legacy low speed multi-mode Fabry-Perot laser and connecting it with an integrated photonic chip with two coupled micro-ring resonators to generate a tunable single mode signal based on Vernier effect for 10Gb/s high speed modulation, which makes it as a promising solution for colorless ONU in future symmetric TWDM-PON.

  1. 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.

  2. Ultraviolet Rayleigh-Mie lidar with Mie-scattering correction by Fabry-Perot etalons for temperature profiling of the troposphere.

    Science.gov (United States)

    Hua, Dengxin; Uchida, Masaru; Kobayashi, Takao

    2005-03-01

    A Rayleigh-Mie-scattering lidar system at an eye-safe 355-nm ultraviolet wavelength that is based on a high-spectral-resolution lidar technique is demonstrated for measuring the vertical temperature profile of the troposphere. Two Rayleigh signals, which determine the atmospheric temperature, are filtered with two Fabry-Perot etalon filters. The filters are located on the same side of the wings of the Rayleigh-scattering spectrum and are optically constructed with a dual-pass optical layout. This configuration achieves a high rejection rate for Mie scattering and reasonable transmission for Rayleigh scattering. The Mie signal is detected with a third Fabry-Perot etalon filter, which is centered at the laser frequency. The filter parameters were optimized by numerical calculation; the results showed a Mie rejection of approximately -45 dB, and Rayleigh transmittance greater than 1% could be achieved for the two Rayleigh channels. A Mie correction method is demonstrated that uses an independent measure of the aerosol scattering to correct the temperature measurements that have been influenced by the aerosols and clouds. Simulations and preliminary experiments have demonstrated that the performance of the dual-pass etalon and Mie correction method is highly effective in practical applications. Simulation results have shown that the temperature errors that are due to noise are less than 1 K up to a height of 4 km for daytime measurement for 300 W m(-2) sr(-1) microm(-1) sky brightness with a lidar system that uses 200 mJ of laser energy, a 3.5-min integration time, and a 25-cm telescope.

  3. 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)

  4. Recent advances and applications of gas chromatography vacuum ultraviolet spectroscopy.

    Science.gov (United States)

    Santos, Inês C; Schug, Kevin A

    2017-01-01

    The vacuum ultraviolet spectrophotometer was developed recently as an alternative to existing gas chromatography detectors. This detector measures the absorption of gas-phase chemical species in the range of 120-240 nm, where all chemical compounds present unique absorption spectra. Therefore, qualitative analysis can be performed and quantification follows standard Beer-Lambert law principles. Different fields of application, such as petrochemical, food, and environmental analysis have been explored. Commonly demonstrated is the capability for facile deconvolution of co-eluting analytes. The concept of additive absorption for co-eluting analytes has also been advanced for classification and speciation of complex mixtures using a data treatment procedure termed time interval deconvolution. Furthermore, pseudo-absolute quantitation can be performed for system diagnosis, as well as potentially calibrationless quantitation. In this manuscript an overview of these features, the vacuum ultraviolet spectrophotometer instrumentation, and performance capabilities are given. A discussion of the applications of the vacuum ultraviolet detector is provided by describing and discussing the papers published thus far since 2014. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Jones matrix description of Fabry-Perot interference in a single axis photo-elastic modulator and the consequences for the magneto-optical measurement method

    Directory of Open Access Journals (Sweden)

    Md. Abdul Ahad Talukder

    2017-08-01

    Full Text Available When using a Photo-elastic modulator (PEM in combination with a coherent light source, in addition to the modulation of the phase, Fabry-Perot interference in the PEM’s optical head induces large offsets in the 1ω and 2ω detector signals. A Jones matrix which describes both effects simultaneously, was derived for a single axis PEM and used to find an expression for the detector signal for two different MO Kerr setups. The effect of the PEM tilt angle, polarizer angle, analyzer angle, and retardation, on the detector signal offsets show that offsets can be zeroed by adjusting PEM tilt angle, polarizer angle, and retardation. This strategy will allow one to avoid large offset drifts due to the small retardation, intensity, and beam direction fluctuations caused by lab temperature fluctuations. In addition, it will enable one to measure in the most sensitive range of the lock-in amplifiers further improving the signal to noise ratio of the setup.

  6. Quasi-analytical synthesis of continuous phase correcting structures to increase the directivity of circularly polarized Fabry-Perot resonator antennas

    International Nuclear Information System (INIS)

    Afzal, Muhammad U.; Esselle, Karu P.

    2015-01-01

    This paper presents a quasi-analytical technique to design a continuous, all-dielectric phase correcting structures (PCSs) for circularly polarized Fabry-Perot resonator antennas (FPRAs). The PCS has been realized by varying the thickness of a rotationally symmetric dielectric block placed above the antenna. A global analytical expression is derived for the PCS thickness profile, which is required to achieve nearly uniform phase distribution at the output of the PCS, despite the non-uniform phase distribution at its input. An alternative piecewise technique based on spline interpolation is also explored to design a PCS. It is shown from both far- and near-field results that a PCS tremendously improves the radiation performance of the FPRA. These improvements include an increase in peak directivity from 22 to 120 (from 13.4 dBic to 20.8 dBic) and a decrease of 3 dB beamwidth from 41.5° to 15°. The phase-corrected antenna also has a good directivity bandwidth of 1.3 GHz, which is 11% of the center frequency

  7. In-line silica capillary tube all-silica fiber-optic Fabry-Perot interferometric sensor for detecting high intensity focused ultrasound fields.

    Science.gov (United States)

    Wang, D H; Wang, S J; Jia, P G

    2012-06-01

    Aiming at detecting high intensity focused ultrasound (HIFU) fields, this letter reports on a novel in-line silica capillary tube all-silica fiber-optic Fabry-Perot (ILSCT-ASFP) interferometric sensor fabricated by splicing a commercially available silica capillary tube to two single-mode fibers. The experimental results show that such a novel ILSCT-ASFP interferometric sensor with a cavity length of ∼60.76 μm has an excellent fringe visibility of up to ∼20 dB, and the fringe visibility is still good when the cavity length extends up to ∼1031.07 μm. The measured wavelength-temperature sensitivity of 0.000858 nm/°C shows that the wavelength drift of the fabricated ILSCT-ASFP interferometric sensor towards temperature is extremely low. Meanwhile, the measurement of HIFU fields by this novel sensor is demonstrated, and the experimental results indicate that the signal-to-noise ratio of the sensing system for sensing a 0.93 MHz HIFU field with a pressure of 2.69 MPa in the focus area can reach 42.8 dB. The corresponding noise equivalent pressure is 0.0194 MPa, and the calculated acoustic sensitivity is 65.4 mV/MPa over a 2.5 MHz measurement bandwidth.

  8. 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.

  9. 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.

  10. Stability of a frequency-comb-based transfer-lock using a passive Fabry-Perot resonator and its application to spectroscopy of ultracold molecules

    Science.gov (United States)

    Pal, Sambit Bikas; Lam, Mark; Dieckmann, Kai

    2017-04-01

    In this poster, we demonstrate a transfer-lock laser frequency stabilization that utilizes a frequency comb (FC) and a radio frequency counter referenced to a GPS frequency standard to compensate for the frequency drifts of two lasers, which are locked to a single passive Fabry-Perot resonator (FPR). The method requires only one optical phase lock with the FC and allows transfer locking of lasers at wavelengths beyond the usable range of the FC. To attain a large frequency tuning range for the lasers, we implement optical serrodyning. We further demonstrate an efficient scheme to suppress residual amplitude modulation, thereby improving the stability of the Pound-Drever-Hall lock used in this case. The absolute frequency stability was found to be better than 2 ×10-13 on timescales up to 300 s. Hence, together with the frequency stability on short timescales provided by the FPR, this scheme facilitates coherent Raman spectroscopy as needed for an example for the production of ultracold dipolar heteronuclear molecules.

  11. DWDM channel spacing tunable optical TDM carrier from a mode-locked weak-resonant-cavity Fabry-Perot laser diode based fiber ring.

    Science.gov (United States)

    Peng, Guo-Hsuan; Chi, Yu-Chieh; Lin, Gong-Ru

    2008-08-18

    A novel optical TDM pulsed carrier with tunable mode spacing matching the ITU-T defined DWDM channels is demonstrated, which is generated from an optically injection-mode-locked weak-resonant-cavity Fabry-Perot laser diode (FPLD) with 10%-end-facet reflectivity. The FPLD exhibits relatively weak cavity modes and a gain spectral linewidth covering >33.5 nm. The least common multiple of the mode spacing determined by both the weak-resonant-cavity FPLD and the fiber-ring cavity can be tunable by adjusting length of the fiber ring cavity or the FPLD temperature to approach the desired 200GHz DWDM channel spacing of 1.6 nm. At a specific fiber-ring cavity length, such a least-common- multiple selection rule results in 12 lasing modes between 1532 and 1545 nm naturally and a mode-locking pulsewidth of 19 ps broadened by group velocity dispersion among different modes. With an additional intracavity bandpass filter, the operating wavelength can further extend from 1520 to 1553.5 nm. After channel filtering, each selected longitudinal mode gives rise to a shortened pulsewidth of 12 ps due to the reduced group velocity dispersion. By linear dispersion compensating with a 55-m long dispersion compensation fiber (DCF), the pulsewidth can be further compressed to 8 ps with its corresponding peak-to-peak chirp reducing from 9.7 to 4.3 GHz.

  12. Side-mode transmission diagnosis of a multichannel selectable injection-locked Fabry-Perot Laser Diode with anti-reflection coated front facet.

    Science.gov (United States)

    Liao, Yu-Sheng; Kuo, Hao-Chung; Chen, Yung-Jui; Lin, Gong-Ru

    2009-03-16

    Theory and experiments on the side-mode-suppression-ratio (SMSR) enhancement and the linewidth reduction of a Fabry-Perot laser diode (FPLD) side-mode-injection-locked by using another FPLD are demonstrated to realize its potential application as a DWDM transmitter source. The SMSR, the spectral linewidth and the linewidth enhancement factor are simulated to realize the limitation of the FPLD-FPLD link under side-mode injection-locking condition. A degradation of the linewidth enhancement factor from 1.5 to 2.1 is observed due to the slave FPLD injection-locked at principle- and side-mode conditions. Up to 22-channel selectability of the 2.5 Gbit/s directly modulated FPLD based transmitter under side-mode injection-locking is demonstrated with a SMSR >35 dB, a Q-factor 6.8-9.2, a locking range of 24 nm, a power penalty of -0.7 dB, and a BER of 10(-10) at -17 dBm. The side-mode injection-locked FPLD shows high-quality transmission performance and meet the demand for cost-effective and high-capability 2.5 Gbit/s WDM systems. (c) 2008 Optical Society of America

  13. 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.

  14. Mitigation of mode partition noise in quantum-dash Fabry-Perot mode-locked lasers using Manchester encoding and balanced detection.

    Science.gov (United States)

    Chaibi, Mohamed Essghair; Bramerie, Laurent; Lobo, Sébastien; Peucheret, Christophe

    2017-07-10

    We propose the use of Manchester encoding in conjunction with balanced detection to overcome the mode partition noise (MPN) limit of quantum-dash Fabry-Perot mode-locked lasers (QD-MLLs) used as multi-wavelength sources in short-reach applications. The proposed approach is demonstrated for a 10-mode laser, each carrying a 10-Gb/s signal. We show that bit-error-rate floors as high as 10 -4 when traditional non-return-to-zero (NRZ) modulation is employed with a single-ended detection scheme can be pushed below 10 -9 thanks to the introduction of Manchester encoding together with balanced detection. The benefit of the scheme could be attributed to the spectral shift of the Manchester spectrum, resulting in a smaller overlap with the high-relative intensity noise (RIN) region present at low frequencies, and the use of balanced detection. We clarify the origin of the performance improvement through comparisons of single-ended and balanced detection and the use of a RIN emulation technique. We unambiguously show that the use of balanced detection plays the leading role in MPN mitigation enabled by Manchester modulation.

  15. 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.

  16. 3m Vacuum Ultraviolet Spectrometer with Optical Multichannel Detector

    International Nuclear Information System (INIS)

    Martin, P.; Peraza, C.; Blanco, F.; Campos, J.

    1993-01-01

    This paper describes the design and the performance of a normal incidence vacuum ultraviolet spectrometer, for the 300-2400 A spectral range. It is provided with a multichannel detection system. The monochromator is original design and it has been built at CIEMAT. It is equipped with a 3 m concave holographic grating with 2400 grooves/mm. The multichannel detector consists of a windowless double microchannel plate / phosphor screen image intensifier, coupled by fiber optic to a 1024 elements self-scanning linear photodiode array. The output from the array is digitized by a 12-bit analog to digital converter and stored in a computer, for its later analysis. The necessary software to store and display data has been developed. (Author) 18 refs

  17. 3m vacuum ultraviolet spectrometer with optical multichanel detector

    International Nuclear Information System (INIS)

    Marin, P.; Peraza, C.; Blanco, F.; Campos, J.

    1993-01-01

    This paper, describes the design and the performance of a normal incidence vacuum ultraviolet spectrometer, for the 300-2400 A spectral range. It is provided with a multichannel detection system. The monochromator is original design and it has been built at CIEMAT: It is equipped with a 3 m concave holographic grating with 2400 grooves/mm. The multichannel detector consists of a windowless double microchannel plate/phosphor screen image intensifier, coupled by fiber optic to a 1024 elements self-scanning linear photodiode array. The output from the arrays is digitized by a 12-bit analog to digital converter and stored in a computer for its later analysis. The necessary software to store and display data has been developed. (Author)

  18. Gas chromatography-vacuum ultraviolet spectroscopy for multiclass pesticide identification.

    Science.gov (United States)

    Fan, Hui; Smuts, Jonathan; Walsh, Phillip; Harrison, Dale; Schug, Kevin A

    2015-04-10

    A new vacuum ultraviolet detector for gas chromatography was recently developed and applied to multiclass pesticide identification. VUV detection features full spectral acquisition in a wavelength range of 115-240nm, where virtually all chemical species absorb. VUV absorption spectra of 37 pesticides across different classes were recorded. These pesticides display rich gas phase absorption features across various classes. Even for isomeric compounds, such as hexachlorocyclohexane (HCH) isomers, the VUV absorption spectra are unique and can be easily differentiated. Also demonstrated is the ability to use VUV data analysis software for deconvolution of co-eluting signals. As a universal detector, VUV provides both qualitative and quantitative information. It offers high specificity, sensitivity (pg on-column detection limits), and a fast data acquisition rate, making it a powerful tool for multiclass pesticide screening when combined with gas chromatography. Copyright © 2015 Elsevier B.V. All rights reserved.

  19. Vacuum ultraviolet photoabsorption spectroscopy of crystalline and amorphous benzene

    DEFF Research Database (Denmark)

    Dawes, Anita; Pascual, Natalia; Hoffmann, Soren V.

    2017-01-01

    We present the first high resolution vacuum ultraviolet photoabsorption study of amorphous benzene with com parisons to annealed crystalline benzene and the gas phase. Vapour deposited benzene layers w ere grow n at 25 K and annealed to 90 K under conditions pertinent to interstellaricy dust grains...... and icy planetary bodies in our solar system. Three single t-single t electronic transitions in solid benzene correspond to the B-1(2u), B-1(1u) and E-1(1u) states, redshifted by 0.05, 0.25 and 0.51 eV respectively with respect to the gas phase. The symmetry forbidden B-1(2u)...

  20. Enabling High Spectral Resolution Thermal Imaging from CubeSat and MicroSatellite Platforms Using Uncooled Microbolometers and a Fabry-Perot interferometer

    Science.gov (United States)

    Wright, R.; Lucey, P. G.; Crites, S.; Garbeil, H.; Wood, M.; Pilger, E. J.; Honniball, C.; Gabrieli, A.

    2016-12-01

    Measurements of reflectance or emittance in tens of narrow, contiguous wavebands, allow for the derivation of laboratory quality spectra remotely, from which the chemical composition and physical properties of targets can be determined. Although spaceborne (e.g. EO-1 Hyperion) hyperspectral data in the 0.4-2.5 micron (VSWIR) region are available, the provision of equivalent data in the log-wave infrared has lagged behind, there being no currently operational high spatial resolution LWIR imaging spectrometer on orbit. This is attributable to two factors. Firstly, earth emits less light than it reflects, reducing the signal available to measure in the TIR, and secondly, instruments designed to measure (and spectrally decompose) this signal are more complex, massive, and expensive than their VSWIR counterparts, largely due to the need to cryogenically cool the detector and optics. However, this measurement gap needs to be filled, as LWIR data provide fundamentally different information than VSWIR measurements. The TIRCIS instrument (Thermal Infra-Red Compact Imaging Spectrometer), developed at the Hawaii Institute of Geophysics and Planetology, uses a Fabry-Perot interferometer, an uncooled microbolometer array, and push-broom scanning to acquire hyperspectral image data in the 8-14 micron spectral range. Radiometric calibration is provided by blackbody targets while spectral calibration is achieved using monochromatic light sources. The instrument has a mass of <15 kg and dimensions of 53 cm × 25 cm × 22 cm, and has been designed to be compatible with integration into a micro-satellite platform. (A precursor to this instrument was launched onboard a 55 kg microsatellite as part of the ORS-4 mission in October 2015). The optical design yields a 120 m ground sample size given an orbit of 500 km. Over the wavelength interval of 7.5 to 14 microns up to 50 spectral samples are possible (the accompanying image shows a quartz spectrum composed of 17 spectral samples). Our

  1. Vacuum ultraviolet spectroscopy study of excimer-laser-generated plasmas

    Science.gov (United States)

    Mehlman, G.; Chrisey, D. B.; Burkhalter, P. G.; Horwitz, J. S.; Newman, D. A.

    1993-07-01

    The dispersed emission in the vacuum ultraviolet (VUV) (1200-3000 Å) from the plasma generated by the interaction of a KrF excimer laser with an Al and a YBa2Cu3O7 target has been measured. Emission spectra were collected as a function of distance above the target surface and as a function of laser fluence. The qualitative features of the plasmas from the two different targets were similar. The character of the emission spectra changed from a pseudocontinuous emission at the target surface to discrete emission from singly, doubly ionized species as well as neutrals at distances greater than ˜1.5 mm. The spatial variation indicated two regions: a high-density sheath along the target where the core emission is close to blackbody; and beyond, a plasma with large opacity emitting a UV spectrum of intensity decreasing fast with distance. Estimates of the plasma temperature and density were between 2 and 4 eV and ˜1018/cm3, respectively.

  2. Permanent gas analysis using gas chromatography with vacuum ultraviolet detection.

    Science.gov (United States)

    Bai, Ling; Smuts, Jonathan; Walsh, Phillip; Fan, Hui; Hildenbrand, Zacariah; Wong, Derek; Wetz, David; Schug, Kevin A

    2015-04-03

    The analysis of complex mixtures of permanent gases consisting of low molecular weight hydrocarbons, inert gases, and toxic species plays an increasingly important role in today's economy. A new gas chromatography detector based on vacuum ultraviolet (VUV) spectroscopy (GC-VUV), which simultaneously collects full scan (115-240 nm) VUV and UV absorption of eluting analytes, was applied to analyze mixtures of permanent gases. Sample mixtures ranged from off-gassing of decomposing Li-ion and Li-metal batteries to natural gas samples and water samples taken from private wells in close proximity to unconventional natural gas extraction. Gas chromatography separations were performed with a porous layer open tubular column. Components such as C1-C5 linear and branched hydrocarbons, water, oxygen, and nitrogen were separated and detected in natural gas and the headspace of natural gas-contaminated water samples. Of interest for the transport of lithium batteries were the detection of flammable and toxic gases, such as methane, ethylene, chloromethane, dimethyl ether, 1,3-butadiene, CS2, and methylproprionate, among others. Featured is the capability for deconvolution of co-eluting signals from different analytes. Copyright © 2015 Elsevier B.V. All rights reserved.

  3. Si nanocrystals embedded in SiO2: Optical studies in the vacuum ultraviolet range

    DEFF Research Database (Denmark)

    Pankratov, V.; Osinniy, Viktor; Kotlov, A.

    2011-01-01

    Photoluminescence excitation and transmission spectra of Si nanocrystals of different diameters embedded in a SiO2 matrix have been investigated in the broad visible-vacuum ultraviolet spectral range using synchrotron radiation. The dependence of the photoluminescence excitation spectra...

  4. Proposed method for obtaining population inversion for vacuum-ultraviolet and x-ray transitions

    International Nuclear Information System (INIS)

    Norton, B.A.; Wooding, E.R.

    1975-01-01

    A method for producing population inversion in a plasma for use as an x-ray or vacuum-ultraviolet lasing medium is described. The process involves a method for removal of the lower quantum levels of an ion, based upon their velocity, which results in an inversion between them and various upper levels. A possible device and its operating characteristics are also discussed

  5. Measurements of transition probabilities in the range from vacuum ultraviolet to infrared

    International Nuclear Information System (INIS)

    Peraza Fernandez, M.C.

    1992-01-01

    In this memory we describe the design, testing and calibration of different spectrometers to measure transition probabilities from the vacuum ultraviolet to the infrared spectral region. For the infrared measurements we have designed and performed a phase sensitive detection system, using an InGaAs photodiode like detector. With this system we have determined the transition probabilities of infrared lines of KrI and XeI. For these lines we haven't found previous measurements. In the vacuum ultraviolet spectral region we have designed a 3 m normal incidence monochromator where we have installed an optical multichannel analyzer. We have tested its accurate working, obtaining the absorption spectrum of KrI. In the visible region we have obtained the emission spectrum of Al using different spectral: hallow-cathode lamp and Nd: YAG laser produced Al plasma. With these spectra we have determined different atomic parameters like transition probabilities and electron temperatures.(author). 83 refs

  6. Development of high resolution vacuum ultraviolet beam line at Indus-1 synchrotron source

    International Nuclear Information System (INIS)

    Shukla, R.P.; Das, N.C.; Udupa, D.V.; Saraswathy, P.; Sunanda, K.; Jha, S.N.; Shastri, Aparna; Singh, Paramjeet; Mallick, Manika; Mishra, A.P.; Sahoo, N.K.; Sinha, A.K.; Bhatt, S.; Sahni, V.C.

    2005-07-01

    High resolution vacuum ultraviolet beamline at Indus-1 450 MeV synchrotron source has been developed for carrying out absorption spectral studies of atoms and molecules. The beamline consists of three major parts i.e. a focusing optical system, an absorption cell and a high resolution 6.65 m vacuum ultraviolet spectrometer in Eagle mount. The wavelength range of the spectrometer is from 700 A to 2000 A and the resolution of the spectrometer is 0.01 A. Using the synchrotron source Indus-1, the absorption spectra of oxygen, ammonia and carbon disulphide have been recorded at the wavelength band of 1750 A, 1881 A and 3100 A respectively. Details of different aspects of design and development of the high resolution VUV beamline are described in this report. (author)

  7. Vacuum ultraviolet transmission spectroscopic system using a laser-produced plasma

    Energy Technology Data Exchange (ETDEWEB)

    Kaku, Masanori; Yamaura, Takahiro; Kodama, Hidenori; Kubodera, Shoichi; Sasaki, Wataru [Miyazaki Univ., Department of Electrical and Electronic Engineering and Photon Science Center, Miyazaki (Japan)

    2001-10-01

    We have developed a vacuum ultraviolet (VUV) spectroscopic system using VUV continua emitting from laser-produced rare gas plasmas. By using this emission source, we have measured VUV transmission spectra of Nd{sup 3+}:LaF{sub 3} crystal. The crystal has a transmission peak at 172 nm and the absorption coefficient is measured to be 1.4 cm{sup -1} at this wavelength. (author)

  8. Complex of imaging diagnostic instruments in the vacuum ultraviolet range for the GOL-3 multimirror trap

    International Nuclear Information System (INIS)

    Burdakov, A.V.; Polosatkin, S.V.; Postupaev, V.V.; Weinzettl, V.; Piffl, V.

    2004-01-01

    Paper describes the GOL-3 multimirror trap base system of imaging diagnostic instruments for vacuum ultraviolet radiation, presents characteristics of the system devices and examples of their operation. Diagnostic procedures serve to acquire information on the plasma basic parameters and to ensure monitoring of facility operation. In combination with the spectroscopic systems the mentioned diagnostic procedures enable to determine dynamics of diffusion of impurities in plasma [ru

  9. Resolution of isomeric new designer stimulants using gas chromatography - Vacuum ultraviolet spectroscopy and theoretical computations.

    Science.gov (United States)

    Skultety, Ludovit; Frycak, Petr; Qiu, Changling; Smuts, Jonathan; Shear-Laude, Lindsey; Lemr, Karel; Mao, James X; Kroll, Peter; Schug, Kevin A; Szewczak, Angelica; Vaught, Cory; Lurie, Ira; Havlicek, Vladimir

    2017-06-08

    Distinguishing isomeric representatives of "bath salts", "plant food", "spice", or "legal high" remains a challenge for analytical chemistry. In this work, we used vacuum ultraviolet spectroscopy combined with gas chromatography to address this issue on a set of forty-three designer drugs. All compounds, including many isomers, returned differentiable vacuum ultraviolet/ultraviolet spectra. The pair of 3- and 4-fluoromethcathinones (m/z 181.0903), as well as the methoxetamine/meperidine/ethylphenidate (m/z 247.1572) triad, provided very distinctive vacuum ultraviolet spectral features. On the contrary, spectra of 4-methylethcathinone, 4-ethylmethcathinone, 3,4-dimethylmethcathinone triad (m/z 191.1310) displayed much higher similarities. Their resolution was possible only if pure standards were probed. A similar situation occurred with the ethylone and butylone pair (m/z 221.1052). On the other hand, majority of forty-three drugs was successfully separated by gas chromatography. The detection limits for all the drug standards were in the 2-4 ng range (on-column amount), which is sufficient for determinations of seized drugs during forensics analysis. Further, state-of-the-art time-dependent density functional theory was evaluated for computation of theoretical absorption spectra in the 125-240 nm range as a complementary tool. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. A study on the resistance performance of epoxy nano-composites under the vacuum ultraviolet irradiation

    Science.gov (United States)

    Liu, Yang; Li, Guo-hui; Jiang, Li-xiang

    2008-12-01

    Irradiation damage effects of the epoxy resin 648 and epoxy nano-composites are studied by means of simulating the vacuum ultraviolet (VUV) irradiation whose wavelength ranges from 5 to 200 nm. Experimental results of the mass loss, SEM and XPS show that nano-TiO 2 particles exhibit better resistance performance under VUV. Comparing with epoxy resin, the epoxy nano-composite brings significantly less mass loss, slighter flexural strength variation and decreasing gas extraction with less gas component varieties after irradiation. What is more, no new carbon peak-value has been found and principle components of Ols peak-value remain unchanged on the surface.

  11. Vacuum ultraviolet light source utilizing rare gas scintillation amplification sustained by photon positive feedback

    Science.gov (United States)

    Aprile, Elena (Inventor); Chen, Danli (Inventor)

    1995-01-01

    A source of light in the vacuum ultraviolet (VUV) spectral region includes a reflective UV-sensitive photocathode supported in spaced parallel relationship with a mesh electrode within a rare gas at low pressure. A high positive potential applied to the mesh electrode creates an electric field which causes drifting of free electrons occurring between the electrodes and producing continuous VUV light output by electric field-driven scintillation amplification sustained by positive photon feedback mediated by photoemission from the photocathode. In one embodiment the lamp emits a narrow-band continuum peaked at 175 nm.

  12. Vacuum-ultraviolet blazed silicon grating anisotropically etched by native-oxide mask.

    Science.gov (United States)

    Sheng, Bin; Xu, Xiangdong; Liu, Ying; Hong, Yilin; Zhou, Hongjun; Huo, Tonglin; Fu, Shaojun

    2009-04-15

    We describe a simple and convenient method of controlling the profile of a blazed grating that consists of using a patterned native-oxide layer of off-cut silicon (111) wafers as the mask of anisotropic etching to maximize the smooth blaze facets of the desired blaze angle and to minimize the deficiencies of the groove apexes. With the blazed-grating profile well controlled by this technique, a 1200 g/mm blazed grating was fabricated that had a blaze angle of 5.0 degrees and smooth blaze facets of about 0.2 nm rms. It was measured to have blaze efficiency in the vacuum-ultraviolet wavelength region.

  13. Test of prototype ITER vacuum ultraviolet spectrometer and its application to impurity study in KSTAR plasmas.

    Science.gov (United States)

    Seon, C R; Hong, J H; Jang, J; Lee, S H; Choe, W; Lee, H H; Cheon, M S; Pak, S; Lee, H G; Biel, W; Barnsley, R

    2014-11-01

    To optimize the design of ITER vacuum ultraviolet (VUV) spectrometer, a prototype VUV spectrometer was developed. The sensitivity calibration curve of the spectrometer was calculated from the mirror reflectivity, the grating efficiency, and the detector efficiency. The calibration curve was consistent with the calibration points derived in the experiment using the calibrated hollow cathode lamp. For the application of the prototype ITER VUV spectrometer, the prototype spectrometer was installed at KSTAR, and various impurity emission lines could be measured. By analyzing about 100 shots, strong positive correlation between the O VI and the C IV emission intensities could be found.

  14. Note: Hollow cathode lamp with integral, high optical efficiency isolation valve: A modular vacuum ultraviolet source

    International Nuclear Information System (INIS)

    Sloan Roberts, F.; Anderson, Scott L.

    2013-01-01

    The design and operating conditions of a hollow cathode discharge lamp for the generation of vacuum ultraviolet radiation, suitable for ultrahigh vacuum (UHV) application, are described in detail. The design is easily constructed, and modular, allowing it to be adapted to different experimental requirements. A thin isolation valve is built into one of the differential pumping stages, isolating the discharge section from the UHV section, both for vacuum safety and to allow lamp maintenance without venting the UHV chamber. The lamp has been used both for ultraviolet photoelectron spectroscopy of surfaces and as a “soft” photoionization source for gas-phase mass spectrometry

  15. Note: Hollow cathode lamp with integral, high optical efficiency isolation valve: A modular vacuum ultraviolet source

    Science.gov (United States)

    Sloan Roberts, F.; Anderson, Scott L.

    2013-12-01

    The design and operating conditions of a hollow cathode discharge lamp for the generation of vacuum ultraviolet radiation, suitable for ultrahigh vacuum (UHV) application, are described in detail. The design is easily constructed, and modular, allowing it to be adapted to different experimental requirements. A thin isolation valve is built into one of the differential pumping stages, isolating the discharge section from the UHV section, both for vacuum safety and to allow lamp maintenance without venting the UHV chamber. The lamp has been used both for ultraviolet photoelectron spectroscopy of surfaces and as a "soft" photoionization source for gas-phase mass spectrometry.

  16. Vacuum-Ultraviolet (VUV) Photoionization of Small Methanol and Methanol-Water Clusters

    Energy Technology Data Exchange (ETDEWEB)

    Kostko, Oleg; Belau, Leonid; Wilson, Kevin R.; Ahmed, Musahid

    2008-04-24

    In this work, we report on the vacuum-ultraviolet (VUV) photoionization of small methanol and methanol-water clusters. Clusters of methanol with water are generated via co-expansion of the gas phase constituents in a continuous supersonic jet expansion of methanol and water seeded in Ar. The resulting clusters are investigated by single photon ionization with tunable vacuum-ultraviolet synchrotron radiation and mass analyzed using reflectron mass spectrometry. Protonated methanol clusters of the form (CH3OH)nH+(n = 1-12) dominate the mass spectrum below the ionization energy of the methanol monomer. With an increase in water concentration, small amounts of mixed clusters of the form (CH3OH n(H2O)H+ (n = 2-11) are detected. The only unprotonated species observed in this work are the methanol monomer and dimer. Appearance energies are obtained from the photoionization efficiency (PIE) curves for CH3OH+, (CH3OH)2+, (CH3OH)nH+ (n = 1-9), and (CH3OH)n(H2O)H+ (n = 2-9) as a function of photon energy. With an increasein the water content in the molecular beam, there is an enhancement of photoionization intensity for the methanol dimer and protonated methanol monomer at threshold. These results are compared and contrasted to previous experimental observations.

  17. Laser Desorption Postionization Mass Spectrometry of Antibiotic-Treated Bacterial Biofilms using Tunable Vacuum Ultraviolet Radiation

    Energy Technology Data Exchange (ETDEWEB)

    Gasper, Gerald L; Takahashi, Lynelle K; Zhou, Jia; Ahmed, Musahid; Moore, Jerry F; Hanley, Luke

    2010-08-04

    Laser desorption postionization mass spectrometry (LDPI-MS) with 8.0 ? 12.5 eV vacuum ultraviolet synchrotron radiation is used to single photon ionize antibiotics andextracellular neutrals that are laser desorbed both neat and from intact bacterial biofilms. Neat antibiotics are optimally detected using 10.5 eV LDPI-MS, but can be ionized using 8.0 eV radiation, in agreement with prior work using 7.87 eV LDPI-MS. Tunable vacuum ultraviolet radiation also postionizes laser desorbed neutrals of antibiotics and extracellular material from within intact bacterial biofilms. Different extracellular material is observed by LDPI-MS in response to rifampicin or trimethoprim antibiotic treatment. Once again, 10.5 eV LDPI-MS displays the optimum trade-off between improved sensitivity and minimum fragmentation. Higher energy photons at 12.5 eV produce significant parent ion signal, but fragment intensity and other low mass ions are also enhanced. No matrix is added to enhance desorption, which is performed at peak power densities insufficient to directly produce ions, thus allowing observation of true VUV postionization mass spectra of antibiotic treated biofilms.

  18. Simultaneous removal of NO and SO2using vacuum ultraviolet light (VUV)/heat/peroxymonosulfate (PMS).

    Science.gov (United States)

    Liu, Yangxian; Wang, Yan; Wang, Qian; Pan, Jianfeng; Zhang, Jun

    2018-01-01

    Simultaneous removal process of SO 2 and NO from flue gas using vacuum ultraviolet light (VUV)/heat/peroxymonosulfate (PMS) in a VUV spraying reactor was proposed. The key influencing factors, active species, reaction products and mechanism of SO 2 and NO simultaneous removal were investigated. The results show that vacuum ultraviolet light (185 nm) achieves the highest NO removal efficiency and yield of and under the same test conditions. NO removal is enhanced at higher PMS concentration, light intensity and oxygen concentration, and is inhibited at higher NO concentration, SO 2 concentration and solution pH. Solution temperature has a double impact on NO removal. CO 2 concentration has no obvious effect on NO removal. and produced from VUV-activation of PMS play a leading role in NO removal. O 3 and ·O produced from VUV-activation of O 2 also play an important role in NO removal. SO 2 achieves complete removal under all experimental conditions due to its very high solubility in water and good reactivity. The highest simultaneous removal efficiency of SO 2 and NO reaches 100% and 91.3%, respectively. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. Development of lasers in the ultraviolet and vacuum ultraviolet for photochemical applications

    International Nuclear Information System (INIS)

    Goujon, Paul.

    1975-06-01

    Intense light sources in the ultraviolet (lambda>200 nm) and in the vacuum ultraviolet (lambda 2 , CO and H 2 , as well as in Ar+H 2 and Ar+N 2 mixtures, have been observed in the near ultraviolet and in vacuum ultraviolet. The pulses last 1.5 to 2 ns and the power varies from 1 to 3 MW. These emissions are produced by a transversely excited laser using a travelling wave discharge, the construction of which is described. The performance of such pulsed lasers is discussed as a function of the various parameters involved. The pulse energy was measured either with a photodiode having a known photocathode yield, or by actinometry, measuring the hydrogen formation by photolysis of ethylene (C 2 H 4 ). This laser can work recurrently with an excellent pulse reproductibility, thus enabling sampling techniques to be employed. The properties sought after in designing this laser are brevity, and reproducibility of the pulse high power and short wavelengths. It is intended as a fundamental research tool for time-resolved molecular spectroscopy studies [fr

  20. Analysis of Fe V and Ni V Wavelength Standards in the Vacuum Ultraviolet

    Science.gov (United States)

    Ward, Jacob Wolfgang; Nave, Gillian

    2015-01-01

    The recent publication[1] by J.C. Berengut et al. tests for a potential variation in the fine-structure constant in the presence of high gravitational potentials through spectral analysis of white-dwarf stars.The spectrum of the white-dwarf star studied in the paper, G191-B2B, has prominent Fe V and Ni V lines, which were used to determine any variation in the fine-structure constant via observed shifts in the wavelengths of Fe V and Ni V in the vacuum ultraviolet region. The results of the paper indicate no such variation, but suggest that refined laboratory values for the observed wavelengths could greatly reduce the uncertainty associated with the paper's findings.An investigation of Fe V and Ni V spectra in the vacuum ultraviolet region has been conducted to reduce wavelength uncertainties currently limiting modern astrophysical studies of this nature. The analyzed spectra were produced by a sliding spark light source with electrodes made of invar, an iron nickel alloy, at peak currents of 750-2000 A. The use of invar ensures that systematic errors in the calibration are common to both species. The spectra were recorded with the NIST Normal Incidence Vacuum Spectrograph on phosphor image plate and photographic plate detectors. Calibration was done with a Pt II spectrum produced by a Platinum Neon Hollow Cathode lamp.[1] J. C. Berengut, V. V. Flambaum, A. Ong, et al Phys. Rev. Lett. 111, 010801 (2013)

  1. Scalable conditional induction variables (CIV) analysis

    KAUST Repository

    Oancea, Cosmin E.

    2015-02-01

    Subscripts using induction variables that cannot be expressed as a formula in terms of the enclosing-loop indices appear in the low-level implementation of common programming abstractions such as Alter, or stack operations and pose significant challenges to automatic parallelization. Because the complexity of such induction variables is often due to their conditional evaluation across the iteration space of loops we name them Conditional Induction Variables (CIV). This paper presents a flow-sensitive technique that summarizes both such CIV-based and affine subscripts to program level, using the same representation. Our technique requires no modifications of our dependence tests, which is agnostic to the original shape of the subscripts, and is more powerful than previously reported dependence tests that rely on the pairwise disambiguation of read-write references. We have implemented the CIV analysis in our parallelizing compiler and evaluated its impact on five Fortran benchmarks. We have found that that there are many important loops using CIV subscripts and that our analysis can lead to their scalable parallelization. This in turn has led to the parallelization of the benchmark programs they appear in.

  2. Is vacuum ultraviolet detector a concentration or a mass dependent detector?

    Science.gov (United States)

    Liu, Huian; Raffin, Guy; Trutt, Guillaume; Randon, Jérôme

    2017-12-29

    The vacuum ultraviolet detector (VUV) is a very effective tool for chromatogram deconvolution and peak identification, and can also be used for quantification. To avoid quantitative issues in relation to time drift, such as variation of peak area or peak height, the detector response type has to be well defined. Due to the make-up flow and pressure regulation of make-up, the detector response (height of the peak) and peak area appeared to be dependent on experimental conditions such as inlet pressure and make-up pressure. Even if for some experimental conditions, VUV looks like mass-flow sensitive detector, it has been demonstrated that VUV is a concentration sensitive detector. Copyright © 2017 Elsevier B.V. All rights reserved.

  3. Two-dimensional vacuum ultraviolet images in different MHD events on the EAST tokamak

    Science.gov (United States)

    Zhijun, WANG; Xiang, GAO; Tingfeng, MING; Yumin, WANG; Fan, ZHOU; Feifei, LONG; Qing, ZHUANG; EAST Team

    2018-02-01

    A high-speed vacuum ultraviolet (VUV) imaging telescope system has been developed to measure the edge plasma emission (including the pedestal region) in the Experimental Advanced Superconducting Tokamak (EAST). The key optics of the high-speed VUV imaging system consists of three parts: an inverse Schwarzschild-type telescope, a micro-channel plate (MCP) and a visible imaging high-speed camera. The VUV imaging system has been operated routinely in the 2016 EAST experiment campaign. The dynamics of the two-dimensional (2D) images of magnetohydrodynamic (MHD) instabilities, such as edge localized modes (ELMs), tearing-like modes and disruptions, have been observed using this system. The related VUV images are presented in this paper, and it indicates the VUV imaging system is a potential tool which can be applied successfully in various plasma conditions.

  4. Metallic Na formation in NaCl crystals with irradiation of electron or vacuum ultraviolet photon

    Energy Technology Data Exchange (ETDEWEB)

    Owaki, Shigehiro [Osaka Prefecture Univ., Sakai, Osaka (Japan). Coll. of Integrated Arts and Sciences; Koyama, Shigeko; Takahashi, Masao; Kamada, Masao; Suzuki, Ryouichi

    1997-03-01

    Metallic Na was formed in NaCl single crystals with irradiation of a variety of radiation sources and analyzed the physical states with several methods. In the case of irradiation of 21 MeV electron pulses to the crystal blocks, the optical absorption and lifetime measurement of positron annihilation indicated appearance of Na clusters inside. Radiation effects of electron beam of 30 keV to the crystals in vacuum showed the appearance of not only metallic Na but atomic one during irradiation with Auger electron spectroscopy. Intense photon fluxes in vacuum ultraviolet region of synchrotron radiation were used as another source and an analyzing method of ultraviolet photoelectron spectroscopy. The results showed the metallic Na layered so thick that bulk plasmon can exist. (author)

  5. Photofragmentation of gas-phase acetic acid and acetamide clusters in the vacuum ultraviolet region

    Science.gov (United States)

    Berholts, Marta; Myllynen, Hanna; Kooser, Kuno; Itälä, Eero; Granroth, Sari; Levola, Helena; Laksman, Joakim; Oghbaiee, Shabnam; Oostenrijk, Bart; Nõmmiste, Ergo; Kukk, Edwin

    2017-11-01

    Photofragmentation of gas-phase acetamide and acetic acid clusters produced by a supersonic expansion source has been studied using time-of-flight mass spectrometry and the partial ion yield (PIY) technique combined with tunable vacuum-ultraviolet synchrotron radiation. Appearance energies of the clusters and their fragments were experimentally determined from the PIY measurements. The effect of clusterization conditions on the formation and fragmentation of acetic acid clusters was investigated. Ab initio quantum mechanical calculations were performed on both samples' dimers to find their neutral and ionized geometries as well as proton transfer energy barriers leading to the optimal geometries. In the case of the acetamide dimer, the reaction resulting in the production of ammoniated acetamide was probed, and the geometry of the obtained ion was calculated.

  6. Enhancement of the vacuum ultraviolet emission from excimer laser-generated plasmas by ambient gas atoms

    Science.gov (United States)

    Mehlman, G.; Chrisey, D. B.; Horwitz, J. S.; Burkhalter, P. G.; Auyeung, R. C. Y.; Newman, D. A.

    1993-11-01

    We have measured the axial (z) and radial (x) distribution of the vacuum ultraviolet emission from excimer laser generated aluminum plasmas in vacuum and in 300 mTorr of argon. The ratio of the radiated line intensities (emission in a gas versus vacuum) on the z axis (i.e., x=0) increased exponentially with distance from the target surface for plasmas generated in a 300 mTorr argon ambient. The absolute line intensities increased linearly with the argon pressure and approximately linearly with the ambient gas atomic cross section when other rare gases were substituted. The line intensity radial distribution was broader for plasmas in argon than in vacuum and the magnitude of the effect increased monotonically with z. The spectral data obtained from plasmas in a gas ambient are discussed in terms of the diffusion of plasma electrons in an ionized gas.

  7. Permanent hydrophilic modification of polypropylene and poly(vinyl alcohol) films by vacuum ultraviolet radiation

    Science.gov (United States)

    Belmonte, Guilherme Kretzmann; Charles, German; Strumia, Miriam Cristina; Weibel, Daniel Eduardo

    2016-09-01

    Polypropylene (PP) and Poly(vinyl alcohol) (PVA) both synthetics polymers but one of them biodegradable, were surface modified by vacuum ultraviolet (VUV) irradiation. After VUV irradiation in an inert nitrogen atmosphere, the films were exposed to oxygen gas. The treated films were characterized by water contact angle measurements (WCA), optical profilometry, FTIR-ATR, XPS, UPS and NEXAFS techniques. PP and PVA VUV-treated films reached superhydrophilic conditions (WCAs styrene (ST) as a typical monomer was tested on PP films. It was confirmed that only in the VUV irradiated region an efficient grafting of ST or polymerized ST was found. Outside the irradiated regions no ST grafted was observed. Our results showed the potential use of VUV treatment for surface modification and processing of polymers which lack chromophores in the UV region.

  8. Amplification properties of vacuum ultraviolet Ar*2 produced by infrared high-intensity laser.

    Science.gov (United States)

    Kaku, Masanori; Harano, Shinya; Matsumoto, Ryota; Katto, Masahito; Kubodera, Shoichi

    2011-07-15

    We report optical amplification of Ar(2)* at 126 nm, pumped by optical-field-induced ionization (OFI) created by an infrared high-intensity laser. A gain-length product of 0.84 was obtained by using multipass amplification with a vacuum ultraviolet (VUV) cavity. The gain-length product was increased up to 4.3 through the use of single-pass amplification with a VUV reflector and a hollow 5.0 cm-long fiber. Similar small signal gain coefficients of 0.84 and 0.86 cm(-1) were obtained in two different experiments, in which OFI Ar plasma gain media were produced in free space filled with Ar and inside an Ar-filled hollow fiber. © 2011 Optical Society of America

  9. Tunable vacuum ultraviolet laser based spectrometer for angle resolved photoemission spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Jiang, Rui; Mou, Daixiang; Wu, Yun; Huang, Lunan; Kaminski, Adam [Division of Materials Science and Engineering, Ames Laboratory, Ames, Iowa 50011 (United States); Department of Physics and Astronomy, Iowa State University, Ames, Iowa 50011 (United States); McMillen, Colin D.; Kolis, Joseph [Department of Chemistry, Clemson University, Clemson, South Carolina 29634 (United States); Giesber, Henry G.; Egan, John J. [Advanced Photonic Crystals LLC, Fort Mill, South Carolina 29708 (United States)

    2014-03-15

    We have developed an angle-resolved photoemission spectrometer with tunable vacuum ultraviolet laser as a photon source. The photon source is based on the fourth harmonic generation of a near IR beam from a Ti:sapphire laser pumped by a CW green laser and tunable between 5.3 eV and 7 eV. The most important part of the set-up is a compact, vacuum enclosed fourth harmonic generator based on potassium beryllium fluoroborate crystals, grown hydrothermally in the US. This source can deliver a photon flux of over 10{sup 14} photon/s. We demonstrate that this energy range is sufficient to measure the k{sub z} dispersion in an iron arsenic high temperature superconductor, which was previously only possible at synchrotron facilities.

  10. Vacuum ultraviolet-induced surface modification of cyclo-olefin polymer substrates for photochemical activation bonding

    International Nuclear Information System (INIS)

    Kim, Young-Jong; Taniguchi, Yoshinao; Murase, Kuniaki; Taguchi, Yoshihiro; Sugimura, Hiroyuki

    2009-01-01

    The surface of cyclo-olefin polymer (COP) was treated with vacuum ultraviolet (VUV) light at 172 nm wavelength to improve the wettability and adhesion properties. Through VUV treatment in air, the terminal groups of the COP surface were oxidized into oxygen functional groups, containing C-O, C=O, and COO components, making the COP surface hydrophilic. The extent of oxygenation was evaluated by XPS and FTIR-ATR spectra, and it was shown that the surface properties, hydrophilicity, and functionalization were dependent on both VUV irradiation distance and irradiation time, which have an effect on the concentration of oxygen functional groups. VUV-light treatment with a short irradiation distance was more effective in introducing oxygen functional groups.

  11. Synchronization of positive surface streamers triggered by vacuum ultraviolet in atmosphere

    International Nuclear Information System (INIS)

    Kashiwagi, Yasuhide; Itoh, Haruo

    2006-01-01

    The synchronous generation of the surface streamer discharges from two electrodes in air is investigated in terms of wavelength and intensity of the discharge light as a trigger for the synchronization of the surface streamers. It is found that the light emitted from the first streamer causes the photoelectron emission and the photoionization in the vicinity of the opposing electrode, triggering synchronous discharge of the second streamer. The wavelength of the light contributing to this phenomenon is shorter than 250 nm, with a remarkable rise in synchronization probability from 164 nm to 115 nm. This is considered to be due to the existence of the photoabsorption windows for oxygen in this vacuum ultraviolet region. These results suggest that the photon energy required to supply initial electrons sufficient to trigger the surface streamers on an acrylic resin insulator is at least 5 eV and more enhancement is found at 8 and 10 eV in this study

  12. Degradation of quinoline and isoquinoline by vacuum ultraviolet light and mechanism thereof

    International Nuclear Information System (INIS)

    Zhu Dazhang; Ni Yaming; Sun Dongmei; Wang Shilong; Sun Xiaoyu; Yao Side

    2010-01-01

    Since the wavelength is shorter than 190 nm, vacuum ultraviolet light has high energy enough to break the H-O bonds of water to produce HO·, as well as the protection is very easy, degradation of organic contaminants in water by vacuum ultraviolet light has obviously excellent feature of no reagent adding to the wastewater among advanced oxidation technologies. In this paper, it was reported that quinoline and isoquinoline were degraded in water by the irradiation of low-pressure quartz mercury light with the electric power of 200 W which mainly emitted the light of 185 nm and 254 nm. The change regulation of the concentration of substrates, chemical oxygen demand (COD) and total organic carbon (TOC) were investigated as well as the degradation processes of quinoline and isoquinoline were compared. It showed that both quinoline and isoquinoline could be degraded very fast under the given conditions. The concentration of the substrates decreased to nearly 0 in 10 minutes while the apparent first reaction rate constants were 0.41 ± 0.02 min -1 and 0.19 ± 0.01 min -1 , respectively. Meanwhile, the COD and TOC decreased to nearly 0 in 30 minutes. Quinoline has the faster degradation rate. In order to investigate mechanism thereof, pulse radiolysis and laser flash photolysis of quinoline and isoquinoline aqueous solution were performed, respectively. Pulse radiolysis indicated that the reaction rate constant of quinoline and HO· was faster than that of isoquinoline. In the meanwhile, laser flash photolysis indicated that both quinoline and isoquinoline could be ionized by the UV-C light while the photo-ionization efficiency of quinoline was higher than that of quinoline. These two reasons caused the faster degradation rate of quinoline. (authors)

  13. Synchrotron Vacuum Ultraviolet Light and Soft X-Ray Radiation Effects on Aluminized Teflon FEP Investigated

    Science.gov (United States)

    Dever, Joyce A.; Townsend, Jacqueline A.; Gaier, James R.; Jalics, Alice I.

    1999-01-01

    Since the Hubble Space Telescope (HST) was deployed in low Earth orbit in April 1990, two servicing missions have been conducted to upgrade its scientific capabilities. Minor cracking of second-surface metalized Teflon FEP (DuPont; fluorinated ethylene propylene) surfaces from multilayer insulation (MLI) was first observed upon close examination of samples with high solar exposure retrieved during the first servicing mission, which was conducted 3.6 years after deployment. During the second HST servicing mission, 6.8 years after deployment, astronaut observations and photographic documentation revealed significant cracks in the Teflon FEP layer of the MLI on both the solar- and anti-solar-facing surfaces of the telescope. NASA Goddard Space Flight Center directed the efforts of the Hubble Space Telescope MLI Failure Review Board, whose goals included identifying the low-Earth-orbit environmental constituent(s) responsible for the cracking and embrittling of Teflon FEP which was observed during the second servicing mission. The NASA Lewis Research Center provided significant support to this effort. Because soft x-ray radiation from solar flares had been considered as a possible cause for the degradation of the mechanical properties of Teflon FEP (ref. 1), the effects of soft xray radiation and vacuum ultraviolet light on Teflon FEP were investigated. In this Lewisled effort, samples of Teflon FEP with a 100-nm layer of vapor-deposited aluminum (VDA) on the backside were exposed to synchrotron radiation of various vacuum ultraviolet and soft x-ray wavelengths between 18 nm (69 eV) and 0.65 nm (1900 eV). Synchrotron radiation exposures were conducted using the National Synchrotron Light Source at Brookhaven National Laboratory. Samples of FEP/VDA were exposed with the FEP surface facing the synchrotron beam. Doses and fluences were compared with those estimated for the 20-yr Hubble Space Telescope mission.

  14. Permanent hydrophilic modification of polypropylene and poly(vinyl alcohol) films by vacuum ultraviolet radiation

    Energy Technology Data Exchange (ETDEWEB)

    Belmonte, Guilherme Kretzmann [Instituto de Química, Universidade Federal do Rio Grande do Sul (UFRGS), Avenida Bento Gonçalves 9500, 91501-970 Porto Alegre, RS (Brazil); Charles, German [Centro de Química Aplicada (CEQUIMAP), Facultad de Ciencias Químicas, Unversidad Nacional de Córdoba, Haya de la Torre y Medina Allende, Edificio de Ciencias II, Ciudad Universitaria, Córdoba 5000 (Argentina); Strumia, Miriam Cristina [Departamento de Química Orgánica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, IPQA-Conicet, Haya de la Torre y Medina Allende, Edificio de Ciencias II, Ciudad Universitaria, Córdoba 5000 (Argentina); Weibel, Daniel Eduardo, E-mail: danielw@iq.ufrgs.br [Instituto de Química, Universidade Federal do Rio Grande do Sul (UFRGS), Avenida Bento Gonçalves 9500, 91501-970 Porto Alegre, RS (Brazil)

    2016-09-30

    Highlights: • Polypropylene and Poly(vinyl alcohol) were surface modified by vacuum ultraviolet (VUV) irradiation. • The hydrophilicity of the treated films was permanent and resisted aging for several months. • Grafting of styrene monomer was only observed in the VUV irradiated regions. • The obtained results showed the potential in the use of VUV treatment for surface modification and processing of polymers which lack chromophores in the UV region. - Abstract: Polypropylene (PP) and Poly(vinyl alcohol) (PVA) both synthetics polymers but one of them biodegradable, were surface modified by vacuum ultraviolet (VUV) irradiation. After VUV irradiation in an inert nitrogen atmosphere, the films were exposed to oxygen gas. The treated films were characterized by water contact angle measurements (WCA), optical profilometry, FTIR-ATR, XPS, UPS and NEXAFS techniques. PP and PVA VUV-treated films reached superhydrophilic conditions (WCAs <10°) in about 30 min of irradiation under our experimental conditions. It was observed that when the WCAs reached about 35–40° the hydrophilicity was permanent in both polymers. These results contrasted with typical plasma treatments were a rapid hydrophobic recovery with aging time is usually observed. UPS and XPS data showed the presence of new functionalities on the PP and PVA surfaces that were assigned to COO, C=O, C−O and C=C functional groups. Finally, grafting of styrene (ST) as a typical monomer was tested on PP films. It was confirmed that only in the VUV irradiated region an efficient grafting of ST or polymerized ST was found. Outside the irradiated regions no ST grafted was observed. Our results showed the potential use of VUV treatment for surface modification and processing of polymers which lack chromophores in the UV region.

  15. Effects of plasma and vacuum-ultraviolet exposure on the mechanical properties of low-k porous organosilicate glass

    Science.gov (United States)

    X. Guo; J.E. Jakes; S. Banna; Y. Nishi; J.L. Shohet

    2014-01-01

    The effects of plasma exposure and vacuum-ultraviolet (VUV) irradiation on the mechanical properties of low-k porous organosilicate glass (SiCOH) dielectric films were investigated. Nanoindentation measurements were made on SiCOH films before and after exposure to an electron-cyclotron-resonance plasma or a monochromatic synchrotron VUV beam, to determine the changes...

  16. System for time-discretized vacuum ultraviolet spectroscopy of spark breakdown in air

    Energy Technology Data Exchange (ETDEWEB)

    Ryberg, D.; Fierro, A.; Dickens, J.; Neuber, A. [Center for Pulsed Power and Power Electronics, Department of Electrical and Computer Engineering and Department of Physics, Texas Tech University, Lubbock, Texas 79409 (United States)

    2014-10-15

    A system for time-discretized spectroscopic measurements of the vacuum ultraviolet (VUV) emission from spark discharges in the 60-160 nm range has been developed for the study of early plasma-forming phenomena. The system induces a spark discharge in an environment close to atmospheric conditions created using a high speed puff value, but is otherwise kept at high vacuum to allow for the propagation of VUV light. Using a vertical slit placed 1.5 mm from the discharge the emission from a small cross section of the discharge is allowed to pass into the selection chamber consisting of a spherical grating, with 1200 grooves/mm, and an exit slit set to 100 μm. Following the exit slit is a photomultiplier tube with a sodium salicylate scintillator that is used for the time discretized measurement of the VUV signal with a temporal resolution limit of 10 ns. Results from discharges studied in dry air, Nitrogen, SF{sub 6}, and Argon indicate the emission of light with wavelengths shorter than 120 nm where the photon energy begins to approach the regime of direct photoionization.

  17. Internal Energies of Ion-Sputtered Neutral Tryptophan and Thymine Molecules Determined by Vacuum Ultraviolet Photoionization

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Jia; Takahashi, Lynelle; Wilson, Kevin R.; Leone, Stephen R.; Ahmed, Musahid

    2010-03-11

    Vacuum ultraviolet photoionization coupled to secondary neutral mass spectrometry (VUV-SNMS) of deposited tryptophan and thymine films are performed at the Chemical Dynamics Beamline. The resulting mass spectra show that while the intensity of the VUV-SNMS signal is lower than the corresponding secondary ion mass spectroscopy (SIMS) signal, the mass spectra are significantly simplified in VUV-SNMS. A detailed examination of tryptophan and thymine neutral molecules sputtered by 25 keV Bi3 + indicates that the ion-sputtered parent molecules have ~;;2.5 eV of internal energy. While this internal energy shifts the appearance energy of the photofragment ions for both tryptophan and thymine, it does not change the characteristic photoionizaton efficiency (PIE) curves of thymine versus photon energy. Further analysis of the mass spectral signals indicate that approximately 80 neutral thymine molecules and 400 tryptophan molecules are sputtered per incident Bi3 + ion. The simplified mass spectra and significant characteristic ion contributions to the VUV-SNMS spectra indicate the potential power of the technique for organic molecule surface analysis.

  18. Schwarzschild microscopes in vacuum ultraviolet and soft X-ray regions

    International Nuclear Information System (INIS)

    Watanabe, M.; Yanagihara, M.; Ejima, T.; Toyoda, M.; Kondo, Y.; Hatano, T.; Tsuru, T.; Yamamoto, M.

    2005-01-01

    Microscopes in vacuum ultraviolet and soft X-ray regions using a normal incidence type of Schwarzschild objective are reviewed. The objective consists of a concave mirror and a convex mirror coated with a high reflectance multilayer, having a large numerical aperture comparing with other objectives. The microscopes have been used to diagnose inertia-confinement-fusion plasmas, and to investigate small samples or microstructures of inorganic and organic materials by imaging them using laboratory light sources. Synchrotron radiation has been also used to obtain a microbeam for a photoelectron scanning microscope with a spatial resolution of 0.1 μm. The structure and performance of two laboratory microscopes developed at Tohoku University are demonstrated. One of them is a soft X-ray emission imaging microscope. An image of an artificial pattern made of W and SiO 2 on Si wafer by focusing Si L emission was presented. The other is an ultraviolet photoelectron scanning microscope using a He (helium) gas discharge lamp. The valence band spectra of a microcrystal of FeWO 4 were presented. Furthermore other applications such as demagnifying optics for lithography and optics to gather fluorescence for emission spectroscopy are introduced. (authors)

  19. Detector calibration in the spectral range from vacuum-ultraviolet to visible

    International Nuclear Information System (INIS)

    Saito, Terubumi

    1994-01-01

    The Electrotechnical Laboratory is responsible for establishing optical units in Japan. Optical units are classified into photometric units which are weighted by human eye responsivity such as candela and radiometric units which are pure physical units such as watt. In this report, the overview of the techniques to determine the radiometric scales for detectors in the spectral region from ultraviolet to visible is described. The characteristics of semiconductor photodiodes as the primary standard detector and rare gas ionization chambers as another example of the primary standard detector are discussed. For characterizing the response of detectors, quantum efficiency or responsivity is used. The definitions of both are given. In order to realize a detector standard, the calibration with a primary standard detector the use of a primary standard radiation source and an efficiency-evaluated monochromatizing component, or the extension of spectral range of an existing detector standard by using a thermal detector is carried out. Noble gas ionization chambers as the primary standard detector in vacuum ultraviolet region, the self-calibration method, and semiconductor photodiodes as the absolute detector are described. (K.I.)

  20. Secondary Structure Prediction of Protein Constructs Using Random Incremental Truncation and Vacuum-Ultraviolet CD Spectroscopy

    Science.gov (United States)

    Pukáncsik, Mária; Orbán, Ágnes; Nagy, Kinga; Matsuo, Koichi; Gekko, Kunihiko; Maurin, Damien; Hart, Darren; Kézsmárki, István; Vertessy, Beata G.

    2016-01-01

    A novel uracil-DNA degrading protein factor (termed UDE) was identified in Drosophila melanogaster with no significant structural and functional homology to other uracil-DNA binding or processing factors. Determination of the 3D structure of UDE is excepted to provide key information on the description of the molecular mechanism of action of UDE catalysis, as well as in general uracil-recognition and nuclease action. Towards this long-term aim, the random library ESPRIT technology was applied to the novel protein UDE to overcome problems in identifying soluble expressing constructs given the absence of precise information on domain content and arrangement. Nine constructs of UDE were chosen to decipher structural and functional relationships. Vacuum ultraviolet circular dichroism (VUVCD) spectroscopy was performed to define the secondary structure content and location within UDE and its truncated variants. The quantitative analysis demonstrated exclusive α-helical content for the full-length protein, which is preserved in the truncated constructs. Arrangement of α-helical bundles within the truncated protein segments suggested new domain boundaries which differ from the conserved motifs determined by sequence-based alignment of UDE homologues. Here we demonstrate that the combination of ESPRIT and VUVCD spectroscopy provides a new structural description of UDE and confirms that the truncated constructs are useful for further detailed functional studies. PMID:27273007

  1. Determination of ionization energies of small silicon clusters with vacuum?ultraviolet (VUV) radiation

    Energy Technology Data Exchange (ETDEWEB)

    Kostko, Oleg; Leone, Stephen R.; Duncan, Michael A.; Ahmed, Musahid

    2009-09-23

    In this work we report on single photon vacuum ultraviolet photoionization of small silicon clusters (n=1-7) produced via laser ablation of Si. The adiabatic ionization energies (AIE) are extracted from experimental photoionization efficiency (PIE) curves with the help of Frank?Condon simulations, used to interpret the shape and onset of the PIE curves. The obtained AIEs are (all energies are in eV): Si (8.13+-0.05), Si2 (7.92+-0.05), Si3 (8.12+-0.05), Si4 (8.2+-0.1), Si5 (7.96+-0.07), Si6 (7.8+-0.1), and Si7 (7.8+-0.1). Most of the experimental AIE values are in good agreement with ab initio electronic structure calculations. To explain observed deviations between the experimental and theoretical AIEs for Si4 and Si6, a theoretical search of different isomers of these species is performed. Electronic structure calculations aid in the interpretation of the a2PIu state of Si2+ dimer in the PIE spectrum. Time dependent density functional theory (TD-DFT) calculations are performed to reveal the energies of electronically excited states in the cations for a number of Si clusters.

  2. Identification and deconvolution of carbohydrates with gas chromatography-vacuum ultraviolet spectroscopy.

    Science.gov (United States)

    Schenk, Jamie; Nagy, Gabe; Pohl, Nicola L B; Leghissa, Allegra; Smuts, Jonathan; Schug, Kevin A

    2017-09-01

    Methodology for qualitative and quantitative determination of carbohydrates with gas chromatography coupled to vacuum ultraviolet detection (GC-VUV) is presented. Saccharides have been intently studied and are commonly analyzed by gas chromatography-mass spectrometry (GC-MS), but not always effectively. This can be attributed to their high degree of structural complexity: α/β anomers from their axial/equatorial hydroxyl group positioning at the C1-OH and flexible ring structures that lead to the open chain, five-membered ring furanose, and six-membered ring pyranose configurations. This complexity can result in convoluted chromatograms, ambiguous fragmentation patterns and, ultimately, analyte misidentification. In this study, mono-, di, and tri-saccharides were derivatized by two different methods-permethylation and oximation/pertrimethylsilylation-and analyzed by GC-VUV. These two derivatization methods were then compared for their efficiency, ease of use, and robustness. Permethylation proved to be a useful technique for the analysis of ketopentoses and pharmaceuticals soluble in dimethyl sulfoxide (DMSO), while the oximation/pertrimethylsilylation method prevailed as the more promising, overall, derivatization method. VUV spectra have been shown to be distinct and allow for efficient differentiation of isomeric species such as ketopentoses and reducing versus non-reducing sugars. In addition to identification, pharmaceutical samples containing several compounds were derivatized and analyzed for their sugar content with the GC-VUV technique to provide data for qualitative analysis. Copyright © 2017 Elsevier B.V. All rights reserved.

  3. Sterilization of Bacillus atrophaeus using OH radicals supplied by vacuum ultraviolet method

    Science.gov (United States)

    Yonetamari, Kenta; Tokumitsu, Yusuke; Yonemori, Seiya; Ono, Ryo; Yasuda, Hachiro; Mizuno, Akira

    2015-09-01

    Sterilization by cold plasma has widely been performed. It is well known that reactive oxygen species (ROS) has a potential of sterilization. However, it is not clear which ROS is effective on sterilization because a lot of types of ROS are produced in plasma. In this study, sterilization effect of OH radicals by vacuum ultraviolet (VUV) method was investigated. This method utilizes photodissociation reaction to produce ROS so it can produce ROS selectively. Wet and dry helium with and without 1% O2 gas was used to demonstrate sterilization effect of OH radicals. Gases were flowed in a quartz tube (inner diameter 2 mm, outer diameter 4 mm) at a flow rate of 1.5 L/min. The produced ROS flowed out of the quartz tube nozzle. A Xe2 excimer lamp emitting 172 +/- 7 nm VUV light was placed parallel to the quartz tube with a distance of 8 mm. The distance between the lower end of the lamp and the nozzle of quartz tube was changed from 3 to 15 cm. As a target of sterilization, Bacillus atrophaeus (ATCC 9372) was used. The density of OH radicals was measured using laser-induced fluorescence (LIF). As a result, sterilization using VUV method was verified. This result showed that OH radicals sterilized the bacteria.

  4. Secondary Structure Prediction of Protein Constructs Using Random Incremental Truncation and Vacuum-Ultraviolet CD Spectroscopy.

    Directory of Open Access Journals (Sweden)

    Mária Pukáncsik

    Full Text Available A novel uracil-DNA degrading protein factor (termed UDE was identified in Drosophila melanogaster with no significant structural and functional homology to other uracil-DNA binding or processing factors. Determination of the 3D structure of UDE is excepted to provide key information on the description of the molecular mechanism of action of UDE catalysis, as well as in general uracil-recognition and nuclease action. Towards this long-term aim, the random library ESPRIT technology was applied to the novel protein UDE to overcome problems in identifying soluble expressing constructs given the absence of precise information on domain content and arrangement. Nine constructs of UDE were chosen to decipher structural and functional relationships. Vacuum ultraviolet circular dichroism (VUVCD spectroscopy was performed to define the secondary structure content and location within UDE and its truncated variants. The quantitative analysis demonstrated exclusive α-helical content for the full-length protein, which is preserved in the truncated constructs. Arrangement of α-helical bundles within the truncated protein segments suggested new domain boundaries which differ from the conserved motifs determined by sequence-based alignment of UDE homologues. Here we demonstrate that the combination of ESPRIT and VUVCD spectroscopy provides a new structural description of UDE and confirms that the truncated constructs are useful for further detailed functional studies.

  5. Vacuum ultraviolet beamline at the Swiss Light Source for chemical dynamics studies

    International Nuclear Information System (INIS)

    Johnson, Melanie; Bodi, Andras; Schulz, Lothar; Gerber, Thomas

    2009-01-01

    A bend-magnet vacuum ultraviolet (VUV) beamline, intended for chemical dynamics studies, was constructed and brought into operation at the Swiss Light Source (SLS) of the Paul Scherrer Institut. The beamline delivers synchrotron radiation in the 5-30 eV photon energy range with a photon flux of 10 11 photons/s at 10 eV and 10 12 photons/s at 20 eV with a resolving power of 2500. The resolving power increases to 10 4 at the cost of photon flux. An in-house designed rare gas filter is used to suppress higher harmonic radiation by a factor of >10 4 , yielding purely monochromatic light in the energy range of 5-21.6 eV. The filter is compact, easy to align, requires a total pumping power of less than 645 l/s and consumes only 3 normal l/h of filter gas. It is located at the end of the beamline, right in front of the experimental endstation. It is usually operated at a higher pressure than the endstation, which offers the additional benefit of protecting the beamline vacuum from sample contamination.

  6. Solid state direct bonding of polymers by vacuum ultraviolet light below 160 nm

    Science.gov (United States)

    Hashimoto, Yuki; Yamamoto, Takatoki

    2017-10-01

    This work investigated the application of vacuum ultraviolet (VUV) irradiation to the bonding of various substrates, including glass, polycarbonate (PC), cyclic olefin polymer (COP), polydimethylsiloxane (PDMS) and polymethyl methacrylate (PMMA). This method has the advantage of being able to bond various substrates without the application of heat or adhesives, and therefore may be very useful in the fabrication of micro/nanoscale structures composed of polymers. In contrast to previous applications of this technique, the present study used VUV radiation at wavelengths at and below 160 nm so as to take advantage of the higher energy in this range. Bonding was assessed based on measuring the shear stress of various test specimens subjected to VUV irradiation and then pressed together, and a number of analytical methods were also employed to examine the irradiated surfaces in order to elucidate the morphological and chemical changes following VUV treatment. These analyses included water contact angle measurements, attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR), time of flight secondary ion mass spectrometry (TOF-SIMS) and atomic force microscopy (AFM). Poor bonding was identified between combinations consisting of PMMA/PC, PMMA/COP, PMMA/PMMA, PMMA/glass, and PC/COP, whereas all other combinations resulted in successful bonding with the bonding stress values such as PC/PC = 2.0 MPa, PC/glass = 10.7 MPa and COP/COP = 1.7 MPa, respectively.

  7. Surface functionalization of graphite and carbon nanotubes by vacuum-ultraviolet photochemical reactions

    Energy Technology Data Exchange (ETDEWEB)

    Girard-Lauriault, Pierre-Luc, E-mail: pierre-luc.girard-lauriault@mcgill.ca [BAM Bundesanstalt fuer Materialforschung und - pruefung, D-12203 Berlin (Germany); Department of Chemical Engineering, McGill University, Montreal, H3A 2B2 (Canada); Illgen, Rene [BAM Bundesanstalt fuer Materialforschung und - pruefung, D-12203 Berlin (Germany); Ruiz, Juan-Carlos; Wertheimer, Michael R. [Groupe de Physique et Technologie des Couches Minces (GCM), Department of Engineering Physics, Ecole Polytechnique, Montreal, QC, H3C3A7 (Canada); Unger, Wolfgang E.S. [BAM Bundesanstalt fuer Materialforschung und - pruefung, D-12203 Berlin (Germany)

    2012-09-01

    Highlights: Black-Right-Pointing-Pointer Graphite and CNT surfaces were functionalized by VUV photochemistry in NH{sub 3} or O{sub 2}. Black-Right-Pointing-Pointer Significant amounts of N and O were incorporated at the materials surface. Black-Right-Pointing-Pointer Primary amine and hydroxyl groups were successfully incorporated at the surface. Black-Right-Pointing-Pointer NEXAFS permitted to assess the conservation of the aromatic structure. - Abstract: Graphite and multiwall carbon nanotube surfaces were functionalized by vacuum-ultraviolet induced photochemistry in NH{sub 3} or O{sub 2}, in order to introduce amino- (NH{sub 2}) or hydroxyl (OH) functionalities, respectively. Modified surfaces were characterized by X-ray photoelectron spectroscopy (XPS), which showed significant incorporation of nitrogen (N) and oxygen (O) at the materials' surface. While high-resolution XP spectra did not yield much specific information about the incorporated functional groups, chemical derivatization with 4-trifluoromethyl benzaldehyde and trifluoroacetic anhydride accompanied by XPS enabled quantification of NH{sub 2} and OH groups, respectively. Using near edge X-ray absorption fine structure spectroscopy, we assessed the conservation of the aromatic structure following functionalization treatments.

  8. Transformation of porous structure under vacuum ultraviolet irradiation of the films based on silicon dioxide

    Energy Technology Data Exchange (ETDEWEB)

    Dultsev, F.N., E-mail: fdultsev@isp.nsc.ru [Institute of Semiconductor Physics SB RAS, Novosibirsk 630090, Lavrentiev ave., 13 (Russian Federation); Novosibirsk State University, 630090, Novosibirsk (Russian Federation); Nekrasov, D.V. [Novosibirsk State University, 630090, Novosibirsk (Russian Federation)

    2016-03-31

    Transformation of the films with the pores of different radii under the action of vacuum ultraviolet radiation was studied experimentally and theoretically. Simulation results showed that Si–O–Si angle depends on pore size. Fourier Transform infrared spectra provide indirect confirmation of this statement. The experimental data and calculation results suggest that methyl group decreases π bonding, which causes a decrease in Si–O–Si angle. The action of ultraviolet radiation is to be considered as a photochemical reaction; the fragments formed in this reaction (CH{sub 3}{sup ⁎}, CH{sub 2}{sup ⁎}) can participate in polymerization, which leads to pore sealing. - Highlights: • Irradiation with the energy of 10–20 eV causes pore sealing. • FTIR studies and simulation results show that Si–O–Si angle depends on pore size. • Fragments formed in photochemical reaction (CH{sub 2}{sup ⁎}) can participate in polymerization. • Polymerization probability is high because the process takes place in closed space.

  9. Scalable conditional induction variables (CIV) analysis

    DEFF Research Database (Denmark)

    Oancea, Cosmin Eugen; Rauchwerger, Lawrence

    2015-01-01

    Subscripts using induction variables that cannot be expressed as a formula in terms of the enclosing-loop indices appear in the low-level implementation of common programming abstractions such as filter, or stack operations and pose significant challenges to automatic parallelization. Because...... representation. Our technique requires no modifications of our dependence tests, which is agnostic to the original shape of the subscripts, and is more powerful than previously reported dependence tests that rely on the pairwise disambiguation of read-write references. We have implemented the CIV analysis in our...

  10. Vacuum-Ultraviolet Photoionization and Mass Spectrometric Characterization of Lignin Monomers Coniferyl and Sinapyl Alcohols

    Energy Technology Data Exchange (ETDEWEB)

    Takahashi, Lynelle K.; Zhou, Jia; Kostko, Oleg; Golan, Amir; Leone, Stephen R.; Ahmed, Musahid

    2011-02-09

    The fragmentation mechanisms of monolignols under various energetic processes are studied with jet-cooled thermal desorption molecular beam (TDMB) mass spectrometry (MS), 25 keV Bi3+ secondary ion MS (SIMS), synchrotron vacuum-ultraviolet secondary neutral MS (VUV-SNMS) and theoretical methods. Experimental and calculated appearance energies of fragments observed in TDMB MS indicate that the coniferyl alcohol photoionization mass spectra contain the molecular parent and several dissociative photoionization products. Similar results obtained for sinapyl alcohol are also discussed briefly. Ionization energies of 7.60 eV ? 0.05 eV for coniferyl alcohol and<7.4 eV for both sinapyl and dihydrosinapyl alcohols are determined. The positive ion SIMS spectrum of coniferyl alcohol shares few characteristic peaks (m/z = 137 and 151) with the TDMB mass spectra, shows extensive fragmentation, and does not exhibit clear molecular parent signals. VUV-SNMS spectra, on the other hand, are dominated by the parent ion and main fragments also present in the TDMB spectra. Molecular fragmentation in VUV-SNMS spectra can be reduced by increasing the extraction delay time. Some features resembling the SIMS spectra are also observed in the desorbed neutral products. The monolignol VUV-SNMS peaks shared with the TDMB mass spectra suggest that dissociative photoionization of ion-sputtered neutral molecules predominate in the VUV-SNMS mass spectra, despite the extra internal energy imparted in the initial ion impact. The potential applications of these results to imaging mass spectrometry of bio-molecules are discussed.

  11. Vacuum ultraviolet spectroscopy and photochemistry of zinc dihydride and related molecules in low-temperature matrices.

    Science.gov (United States)

    Henchy, Chris; Kilmartin, Una; McCaffrey, John G

    2013-09-26

    Optical absorption spectra of thin film samples, formed by the codeposition of zinc vapor with D2 and CH4, have been recorded with synchrotron radiation. With sufficiently low metal vapor flux, samples deposited at 4 K were found to consist exclusively of isolated zinc atoms for both solids. The atomic absorption bands in the quantum solids D2 and CH4 were found to exhibit large bandwidths, behavior related to the high lattice frequencies of these low mass solids. The reactivity of atomic zinc was promoted with (1)P state photolysis leading to the first recording of electronic absorption spectra for the molecules ZnD2 and CH3ZnH in the vacuum ultraviolet (VUV) region. (3)P state luminescence of atomic zinc observed in the Zn/CH4 system points to the involvement of the spin triplet state in the relaxation of CH3ZnH system as it evolves into the C3v ground state. This state is not involved in the relaxation of the higher symmetry molecule ZnD2. Time dependent density functional theory (TD-DFT) calculations were conducted to predict the electronic transitions of the inserted molecular species. Comparisons with experimental data indicate the predicted transition energies are approximately 0.5 eV less than the recorded values. Possible reasons for the discrepancy are discussed. The molecular photochemistry of ZnD2 and CH3ZnH observed in the VUV was modeled successfully with a simple four-valence electron AH2 Walsh-type diagram.

  12. Degradation of organic pollutants by Vacuum-Ultraviolet (VUV): Kinetic model and efficiency.

    Science.gov (United States)

    Xie, Pengchao; Yue, Siyang; Ding, Jiaqi; Wan, Ying; Li, Xuchun; Ma, Jun; Wang, Zongping

    2018-04-15

    Vacuum-Ultraviolet (VUV), an efficient and green method to produce hydroxyl radical (•OH), is effective in degrading numerous organic contaminants in aqueous solution. Here, we proposed an effective and simple kinetic model to describe the degradation of organic pollutants in VUV system, by taking the •OH scavenging effects of formed organic intermediates as co-existing organic matter in whole. Using benzoic acid (BA) as a •OH probe, •OH was regarded vital for pollutant degradation in VUV system, and the thus developed model successfully predicted its degradation kinetics under different conditions. Effects of typical influencing factors such as BA concentrations and UV intensity were investigated quantitatively by the model. Temperature was found to be an important influencing factor in the VUV system, and the quantum yield of •OH showed a positive linear dependence on temperature. Impacts of humic acid (HA), alkalinity, chloride, and water matrices (realistic waters) on the oxidation efficiency were also examined. BA degradation was significantly inhibited by HA due to its scavenging of •OH, but was influenced much less by the alkalinity and chloride; high oxidation efficiency was still obtained in the realistic water. The degradation kinetics of three other typical micropollutants including bisphenol A (BPA), nitrobenzene (NB) and dimethyl phthalate (DMP), and the mixture of co-existing BA, BPA and DMP were further studied, and the developed model predicted the experimental data well, especially in realistic water. It is expected that this study will provide an effective approach to predict the degradation of organic micropollutants by the promising VUV system, and broaden the application of VUV system in water treatment. Copyright © 2018 Elsevier Ltd. All rights reserved.

  13. Two-color visible/vacuum ultraviolet photoelectron imaging dynamics of Br2.

    Science.gov (United States)

    Plenge, Jürgen; Nicolas, Christophe; Caster, Allison G; Ahmed, Musahid; Leone, Stephen R

    2006-10-07

    An experimental two-color photoionization dynamics study of laser-excited Br2 molecules is presented, combining pulsed visible laser excitation and tunable vacuum ultraviolet (VUV) synchrotron radiation with photoelectron imaging. The X 1Sigmag + -B 3Pi0+u transition in Br2 is excited at 527 nm corresponding predominantly to excitation of the v' = 28 vibrational level in the B 3Pi0+u state. Tunable VUV undulator radiation in the energy range of 8.40-10.15 eV is subsequently used to ionize the excited molecules to the X 2Pi32,12 state of the ion, and the ionic ground state is probed by photoelectron imaging. Similar experiments are performed using single-photon synchrotron ionization in the photon energy range of 10.75-12.50 eV without any laser excitation. Photoelectron kinetic energy distributions are extracted from the photoelectron images. In the case of two-color photoionization using resonant excitation of the intermediate B 3Pi0+u state, a broad distribution of photoelectron kinetic energies is observed, and in some cases even a bimodal distribution, which depends on the VUV photon energy. In contrast, for single-photon ionization, a single nearly Gaussian-shaped distribution is observed, which shifts to higher energy with photon energy. Simulated spectra based on Franck-Condon factors for the transitions Br2(X 1Sigmag+, v" = 0)-Br2 +(X 2Pi12,32, v+) and Br2(B 3Pi0+u, v' = 28)-Br2 +(X 2Pi12,32, v+) are generated. Comparison of these calculated spectra with the measured images suggests that the differences in the kinetic energy distributions for the two ionization processes reflect the different extensions of the vibrational wave functions in the v" = 0 electronic ground state (X 1Sigmag+) versus the electronically and vibrationally excited state (B 3Pi0+u, v' = 28).

  14. Sulfur Isotopic Fractionation During Vacuum Ultraviolet Photolysis of SO2: Implication for Meteorites and Early Earth

    Science.gov (United States)

    Chakraborty, S.; Jackson, T. L.; Rude, B.; Ahmed, M.; Thiemens, M. H.

    2016-12-01

    Several sulfur bearing gas phase species existed in the solar nebula, including H2S, SO2, SiS, OCS, CS2, CS, NS and SO as a consequence of multiple available chemical valence states (S2- to S6+). Sulfur directly condensed into refractory phases in the solar nebula under reducing conditions. Mass independent (MI) sulfur isotopic compositions have been measured in chondrules and organics from chondritic meteorites. Large 33S excesses in sulfides from achondrite meteoritic groups have also been found suggesting that refractory sulfide minerals condensed from a nebular gas with an enhanced carbon to oxygen ratio. Photochemical reactions in the early solar nebula have been inferred to be a leading process in generating MI sulfur compositions. Previously, we have reported wavelength dependent mass-independent sulfur isotopic compositions (with a varying degree in D33S and D36S) in the product elemental sulfur during vacuum ultraviolet (VUV) photodissociation of H2S. Recently we performed photodissociation of SO2 experiments in the wavelength region 98 to 200 nm at low pressures (0.5 torr) using the VUV photons from the Advanced Light Source Synchrotron in a differentially pumped reaction chamber. To our knowledge, this is the first ever experiment to determine the isotopic fractionation in VUV photodissociation of SO2. At VUV energy region, SO2 is mostly predissociative. The measured sulfur isotopic compositions in the product elemental sulfur are MI and dependent on the wavelength. These new results support the previous finding from photodissociation of other di- and tri-atomic molecules (CO, N2, H2S) that predissociative photodissociation produces MI isotopic products and is a quantum mechanically driven selective phenomenon. These new results are useful because (i) they are important in interpreting meteoritic data and decipher sulfur chemistry in the early nebula which is indicative of the redox condition of the nebula (ii) SO2 photolysis in the atmosphere of early

  15. High-Resolution Electronics: Spontaneous Patterning of High-Resolution Electronics via Parallel Vacuum Ultraviolet (Adv. Mater. 31/2016).

    Science.gov (United States)

    Liu, Xuying; Kanehara, Masayuki; Liu, Chuan; Sakamoto, Kenji; Yasuda, Takeshi; Takeya, Jun; Minari, Takeo

    2016-08-01

    On page 6568, T. Minari and co-workers describe spontaneous patterning based on the parallel vacuum ultraviolet (PVUV) technique, enabling the homogeneous integration of complex, high-resolution electronic circuits, even on large-scale, flexible, transparent substrates. Irradiation of PVUV to the hydrophobic polymer surface precisely renders the selected surface into highly wettable regions with sharply defined boundaries, which spontaneously guides a metal nanoparticle ink into a series of circuit lines and gaps with the widths down to a resolution of 1 μm. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Absolute calibration of space- and time-resolving flat-field vacuum ultraviolet spectrograph for plasma diagnostics

    Energy Technology Data Exchange (ETDEWEB)

    Okamoto, Yuuji; Yoshikawa, Masayuki; Watabe, Chikara; Tamano, Teruo; Kawamori, Eiichirou; Ito, Takahiro; Watanabe, Yoshihiko; Yatsu, Kiyoshi [Plasma Research Center, Tsukuba Univ., Ibaraki (Japan); Yamaguchi, Naohiro [Toyota Technological Inst., Nagoya (Japan)

    2000-06-01

    Measurement of spectra in the wavelength range from vacuum ultraviolet (VUV) to soft X-ray is an important means to diagnose impurities in magnetically confined plasmas used in fusion plasmas such as a GAMMA10 plasma. Recently, a space- and time-resolving flat-field grazing-incidence VUV spectrograph was constructed for the simultaneous observation of spatial, temporal and spectral distributions of plasma radiation in the wavelength range of 150-1050 A. Absolute calibration experiments were performed at beamline 11C in the Photon Factory at the High Energy Accelerator Research Organization. The absolute efficiency of the VUV spectrograph was measured for P polarization geometry in the spectrograph. (author)

  17. Absolute calibration of space- and time-resolving flat-field vacuum ultraviolet spectrograph for plasma diagnostics

    International Nuclear Information System (INIS)

    Okamoto, Yuuji; Yoshikawa, Masayuki; Watabe, Chikara; Tamano, Teruo; Kawamori, Eiichirou; Ito, Takahiro; Watanabe, Yoshihiko; Yatsu, Kiyoshi; Yamaguchi, Naohiro

    2000-01-01

    Measurement of spectra in the wavelength range from vacuum ultraviolet (VUV) to soft X-ray is an important means to diagnose impurities in magnetically confined plasmas used in fusion plasmas such as a GAMMA10 plasma. Recently, a space- and time-resolving flat-field grazing-incidence VUV spectrograph was constructed for the simultaneous observation of spatial, temporal and spectral distributions of plasma radiation in the wavelength range of 150-1050 A. Absolute calibration experiments were performed at beamline 11C in the Photon Factory at the High Energy Accelerator Research Organization. The absolute efficiency of the VUV spectrograph was measured for P polarization geometry in the spectrograph. (author)

  18. Surface Emitting, High Efficiency Near-Vacuum Ultraviolet Light Source with Aluminum Nitride Nanowires Monolithically Grown on Silicon.

    Science.gov (United States)

    Zhao, S; Djavid, M; Mi, Z

    2015-10-14

    To date, it has remained challenging to realize electrically injected light sources in the vacuum ultraviolet wavelength range (∼200 nm or shorter), which are important for a broad range of applications, including sensing, surface treatment, and photochemical analysis. In this Letter, we have demonstrated such a light source with molecular beam epitaxially grown aluminum nitride (AlN) nanowires on low cost, large area Si substrate. Detailed angle dependent electroluminescence studies suggest that, albeit the light is TM polarized, the dominant light emission direction is from the nanowire top surface, that is, along the c axis, due to the strong light scattering effect. Such an efficient surface emitting device was not previously possible using conventional c-plane AlN planar structures. The AlN nanowire LEDs exhibit an extremely large electrical efficiency (>85%), which is nearly ten times higher than the previously reported AlN planar devices. Our detailed studies further suggest that the performance of AlN nanowire LEDs is predominantly limited by electron overflow. This study provides important insight on the fundamental emission characteristics of AlN nanowire LEDs and also offers a viable path to realize an efficient surface emitting near-vacuum ultraviolet light source through direct electrical injection.

  19. Exploiting single photon vacuum ultraviolet photoionization to unravel the synthesis of complex organic molecules in interstellar ices

    Science.gov (United States)

    Abplanalp, Matthew J.; Förstel, Marko; Kaiser, Ralf I.

    2016-01-01

    Complex organic molecules (COM) such as aldehydes, ketones, carboxylic acids, esters, and amides are ubiquitous in the interstellar medium, but traditional gas phase astrochemical models cannot explain their formation routes. By systematically exploiting on line and in situ vacuum ultraviolet photoionization coupled with reflectron time of flight mass spectrometry (PI-ReTOF-MS) and combining these data with infrared spectroscopy (FTIR), we reveal that complex organic molecules can be synthesized within interstellar ices that are condensed on interstellar grains via non-equilibrium reactions involving suprathermal hydrogen atoms at temperatures as low as 5 K. By probing for the first time specific structural isomers without their degradation (fragment-free), the incorporation of tunable vacuum ultraviolet photoionization allows for a much greater understanding of reaction mechanisms that exist in interstellar ices compared to traditional methods, thus eliminating the significant gap between observational and laboratory data that existed for the last decades. With the commission of the Atacama Large Millimeter/Submillimeter Array (ALMA), the number of detections of more complex organic molecules in space will continue to grow ⿿ including biorelevant molecules connected to the Origins of Life theme ⿿ and an understanding of these data will rely on future advances in sophisticated physical chemistry laboratory experiments.

  20. Gas phase radiolysis and vacuum ultraviolet photolysis of heterocyclic organic compounds. Progress report, February 1, 1974--February 1, 1975

    International Nuclear Information System (INIS)

    Scala, A.A.; Salomon, D.; Colon, I.; D'Angona, J.

    1975-01-01

    In the γ radiolysis of tetrahydrofuran there are pronounced density effects in the pressure range from 0 to 50 Torr with the most important ion-pair yields decreasing as the pressure increases. The relative product yields of the radiolysis is compared with that of xenon photolysis. Possible mechanisms to explain the results obtained are discussed. The ion-pair yields from the γ radiolysis of the heterocyclic amines, ethylenimine, azetidine, pyrrolidine, and piperidine, are determined, and the pressure effects are evaluated. Reactions mechanisms are discussed. The vacuum ultraviolet photolysis products of thietane and tetrahydrothiophene are studied and compared with the γ radiolysis products. Reaction mechanisms are discussed. The status of the construction of a photoionization mass spectrometer and the measurement of the ionization efficiencies and extinction coefficients of organic compounds is reported. (U.S.)

  1. Vacuum ultraviolet-ultraviolet and x-ray excited luminescence properties of Ba3Gd(BO3)3:Ce3+

    NARCIS (Netherlands)

    Han, B.; Liang, H.; Lin, H.; Zhong, J.; Su, Q.; Dorenbos, P.; Birowosuto, M.D.; Zhang, G.; Fu, Y.

    2007-01-01

    The phosphors Ba3Gd(BO3)3:Ce3+ were prepared by a solid-state reaction technique at high temperature. The vacuum ultraviolet-ultraviolet and visible spectroscopic properties of the phosphors together with decay time curves are investigated and discussed. The spectroscopic properties are explained by

  2. Ultraviolet-vacuum ultraviolet photoluminescence and x ray radioluminescence of Ce3+-doped Ba3MgSi2O8

    NARCIS (Netherlands)

    Ding, X.; Liang, H.; Hou, D.; Su, Q.; Dorenbos, P.; Sun, S.; Tao, Y.

    2011-01-01

    Ce3+-doped Ba3MgSi2O8 phosphors were prepared by a solid-state reaction route. The photoluminescence properties in the vacuum ultraviolet-vis spectral range and the x ray excited radioluminescence were investigated. Ce3+ ions were found to enter three different sites in the host lattice. Five

  3. Fiscal state aid and real estate collective investment vehicles (CIVs)

    NARCIS (Netherlands)

    Vermeulen, H.

    2011-01-01

    State aid is an issue that does not immediately come to mind on the topic of real estate collective investment vehicles (CIVs). Nevertheless the question of state aid plays an important role. Last year, the European Commission charged with the monitoring of state aid has taken an important decision

  4. Spectrograms of the JT-60 plasmas in the vacuum ultraviolet region (wavelength region 15 ∼ 1360 A)

    International Nuclear Information System (INIS)

    Kubo, Hirotaka; Sugie, Tatsuo; Sakasai, Akira; Koide, Yoshihiko; Nishino, Nobuhiro; Akaoka, Nobuo

    1988-07-01

    Spectrograms in the vacuum ultraviolet region have been obtained by a 3 m grazing incidence spectrograph in order to study impurity behaviors in JT-60 plasma. The spectrograms have been investigated in the first OH experiments, High-Ti mode experiments, and the experiments that were carried out after the replacement of 40 % of the first wall of the vacuum vessel with graphite tiles. In the first OH experiments, the spectrogram which covered the wavelength region of 15 ∼ 1360 A was obtained, and spectral lines of oxygen, carbon, and titanium were identified. In High-Ti mode experiments, the spectrogram which covered the wavelength region of 17 ∼ 77 A was obtained, and spectral lines of highly ionized molybdenum were identified in addition to those of oxygen, carbon, and titanium. In the experiments after the replacement of the first wall, the spectrogram which covered the wavelength region of 15 ∼ 55 A was obtained, and it was found clearly that the metallic impurities decreased. (author)

  5. Photocatalytic pretreatment of oily wastewater from the restaurant by a vacuum ultraviolet/TiO2 system

    International Nuclear Information System (INIS)

    Kang Jianxiong; Lu Lu; Zhan Wei; Li Bo; Li Daosheng; Ren Yongzheng; Liu Dongqi

    2011-01-01

    The present study aims at investigating the performance of a vacuum ultraviolet (VUV, 185 nm) and TiO 2 oxidation system for the pretreatment of oily wastewater from restaurant. The influence of irradiation time, pH, dissolved oxygen (DO), the dosage of TiO 2 and the initial chemical oxygen demand (COD) concentration on COD removal efficiency was ascertained and optimum process conditions for stable and effective operation were determined. Under the optimum conditions of irradiation 10 min, initial COD 3981 mg/L, TiO 2 150 mg/L, pH 7.0 and flow rate of air 40 L/h, the process of VUV and TiO 2 /VUV achieved removal efficiencies of COD, BOD 5 and oil as 50 ± 3%, 37 ± 2%, 86 ± 3%, and 63 ± 3%, 43 ± 2%, 70 ± 3%, respectively. The biodegradability factor f B of the wastewater was determined as 1.56 which indicated that the VUV/TiO 2 process improved the biodegradability of the oily wastewater significantly. Results clearly indicate that VUV/TiO 2 photolysis tends to destruct parts of COD, BOD 5 , and ammonia, as well as enhances the biodegradability of the oily wastewater simultaneously. Thus, this technique could be used as a pretreatment step for conventional biological treatment of oily wastewater.

  6. Improved Resolution of Hydrocarbon Structures and Constitutional Isomers in Complex Mixtures Using Gas Chromatography-Vacuum Ultraviolet-Mass Spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Isaacman, Gabriel [Univ. of California, Berkeley, CA (United States); Wilson, Kevin R. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Chan, Arthur W. H. [Univ. of California, Berkeley, CA (United States); Worton, David R. [Univ. of California, Berkeley, CA (United States). Aerosol Dynamics Inc., Berkeley, CA (United States); Kimmel, Joel R. [Aerodyne Research, Inc., Billerica, MA (United States); Univ. of Colorado, Boulder, CO (United States). Tofwerk AG, Thun (Switzerland); Nah, Theodora [Univ. of California, Berkeley, CA (United States); Hohaus, Thorsten [Aerodyne Research, Inc., Billerica, MA (United States); Gonin, Marc [Tofwerk AG, Thun (Switzerland); Kroll, Jesse H. [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); Worsnop, Douglas R. [Aerodyne Research, Inc., Billerica, MA (United States); Goldstein, Allen H. [Univ. of California, Berkeley, CA (United States); Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2012-01-30

    Understanding the composition of complex hydrocarbon mixtures is important for environmental studies in a variety of fields, but many prevalent compounds cannot be confidently identified using traditional gas chromatography/mass spectrometry (GC/MS) techniques. In this study, we use vacuum-ultraviolet (VUV) ionization to elucidate the structures of a traditionally “unresolved complex mixture” by separating components by GC retention time, tR, and mass-to-charge ratio, m/z, which are used to determine carbon number, NC, and the number of rings and double bonds, NDBE. Constitutional isomers are resolved on the basis of tR, enabling the most complete quantitative analysis to date of structural isomers in an environmentally relevant hydrocarbon mixture. Unknown compounds are classified in this work by carbon number, degree of saturation, presence of rings, and degree of branching, providing structural constraints. The capabilities of this analysis are explored using diesel fuel, in which constitutional isomer distribution patterns are shown to be reproducible between carbon numbers and follow predictable rules. Nearly half of the aliphatic hydrocarbon mass is shown to be branched, suggesting branching is more important in diesel fuel than previously shown. Lastly, the classification of unknown hydrocarbons and the resolution of constitutional isomers significantly improves resolution capabilities for any complex hydrocarbon mixture.

  7. Desorption Dynamics, Internal Energies and Imaging of Organic Molecules from Surfaces with Laser Desorption and Vacuum Ultraviolet (VUV) Photoionization

    Energy Technology Data Exchange (ETDEWEB)

    Kostko, Oleg; Takahashi, Lynelle K.; Ahmed, Musahid

    2011-04-05

    There is enormous interest in visualizing the chemical composition of organic material that comprises our world. A convenient method to obtain molecular information with high spatial resolution is imaging mass spectrometry. However, the internal energy deposited within molecules upon transfer to the gas phase from a surface can lead to increased fragmentation and to complications in analysis of mass spectra. Here it is shown that in laser desorption with postionization by tunable vacuum ultraviolet (VUV) radiation, the internal energy gained during laser desorption leads to minimal fragmentation of DNA bases. The internal temperature of laser-desorbed triacontane molecules approaches 670 K, whereas the internal temperature of thymine is 800 K. A synchrotron-based VUV postionization technique for determining translational temperatures reveals that biomolecules have translational temperatures in the range of 216-346 K. The observed low translational temperatures, as well as their decrease with increased desorption laser power is explained by collisional cooling. An example of imaging mass spectrometry on an organic polymer, using laser desorption VUV postionization shows 5 mu m feature details while using a 30 mu m laser spot size and 7 ns duration. Applications of laser desorption postionization to the analysis of cellulose, lignin and humic acids are briefly discussed.

  8. Effects of vacuum-ultraviolet irradiation on copper penetration into low-k dielectrics under bias-temperature stress

    Energy Technology Data Exchange (ETDEWEB)

    Guo, X.; Zheng, H.; Xue, P.; Shohet, J. L. [Plasma Processing and Technology Laboratory and Department of Electrical and Computer Engineering, University of Wisconsin-Madison, Madison, Wisconsin 53706 (United States); King, S. W. [Logic Technology Development, Intel Corporation, Hillsboro, Oregon 97124 (United States); Nishi, Y. [Department of Electrical Engineering, Stanford University, Stanford, California 94305 (United States)

    2015-01-05

    The effects of vacuum-ultraviolet (VUV) irradiation on copper penetration into non-porous low-k dielectrics under bias-temperature stress (BTS) were investigated. By employing x-ray photoelectron spectroscopy depth-profile measurements on both as-deposited and VUV-irradiated SiCOH/Cu stacks, it was found that under the same BTS conditions, the diffusion depth of Cu into the VUV-irradiated SiCOH is higher than that of as-deposited SiCOH. On the other hand, under the same temperature-annealing stress (TS) without electric bias, the Cu distribution profiles in the VUV-irradiated SiCOH were same with that for the as-deposited SiCOH. The experiments suggest that in as-deposited SiCOH, the diffused Cu exists primarily in the atomic state, while in VUV-irradiated SiCOH, the diffused Cu is oxidized by the hydroxyl ions (OH{sup −}) generated from VUV irradiation and exists in the ionic state. The mechanisms for metal diffusion and ion injection in VUV irradiated low-k dielectrics are discussed.

  9. Photodissociation dynamics of H2O at 111.5 nm by a vacuum ultraviolet free electron laser

    Science.gov (United States)

    Wang, Heilong; Yu, Yong; Chang, Yao; Su, Shu; Yu, Shengrui; Li, Qinming; Tao, Kai; Ding, Hongli; Yang, Jaiyue; Wang, Guanglei; Che, Li; He, Zhigang; Chen, Zhichao; Wang, Xingan; Zhang, Weiqing; Dai, Dongxu; Wu, Guorong; Yuan, Kaijun; Yang, Xueming

    2018-03-01

    Photodissociation dynamics of H2O via the F ˜ state at 111.5 nm were investigated using the high resolution H-atom Rydberg "tagging" time-of-flight (TOF) technique, in combination with the tunable vacuum ultraviolet free electron laser at the Dalian Coherent Light Source. The product translational energy distributions and angular distributions in both parallel and perpendicular directions were derived from the recorded TOF spectra. Based on these distributions, the quantum state distributions and angular anisotropy parameters of OH (X) and OH (A) products have been determined. For the OH (A) + H channel, highly rotationally excited OH (A) products have been observed. These products are ascribed to a fast direct dissociation on the B ˜ 1A1 state surface after multi-step internal conversions from the initial excited F ˜ state to the B ˜ state. While for the OH (X) + H channel, very highly rotationally excited OH (X) products with moderate vibrational excitation are revealed and attributed to the dissociation via a nonadiabatic pathway through the well-known two conical intersections between the B ˜ -state and the X ˜ -state surfaces.

  10. Real-time analysis of soot emissions from bituminous coal pyrolysis and combustion with a vacuum ultraviolet photoionization aerosol time-of-flight mass spectrometer.

    Science.gov (United States)

    Gao, Shaokai; Zhang, Yang; Meng, Junwang; Shu, Jinian

    2009-01-15

    This paper reports on-line analyses of the soot emissions from the Inner Mongolia bituminous coal combustion and pyrolysis processes with a vacuum ultraviolet photoionization aerosol time-of-flight mass spectrometer (VUV-ATOFMS). The soot particles are generated by heating a small amount of screened coal powder in synthetic air and nitrogen atmosphere in a tubular oven. The vacuum ultraviolet photoionization time-of-flight (VUV-TOF) mass spectra of the soot particles emitted from combustion and pyrolysis at different oven temperatures and different stages are obtained. The VUV-TOF mass spectra are assigned with the references of the results of the off-line GC/MS analysis.

  11. A single-shot nonlinear autocorrelation approach for time-resolved physics in the vacuum ultraviolet spectral range

    International Nuclear Information System (INIS)

    Rompotis, Dimitrios

    2016-02-01

    In this work, a single-shot temporal metrology scheme operating in the vacuum-extreme ultraviolet spectral range has been designed and experimentally implemented. Utilizing an anti-collinear geometry, a second-order intensity autocorrelation measurement of a vacuum ultraviolet pulse can be performed by encoding temporal delay information on the beam propagation coordinate. An ion-imaging time-of-flight spectrometer, offering micrometer resolution has been set-up for this purpose. This instrument enables the detection of a magnified image of the spatial distribution of ions exclusively generated by direct two-photon absorption in the combined counter-propagating pulse focus and thus obtain the second-order intensity autocorrelation measurement on a single-shot basis. Additionally, an intense VUV light source based on high-harmonic generation has been experimentally realized. It delivers intense sub-20 fs Ti:Sa fifth-harmonic pulses utilizing a loose-focusing geometry in a long Ar gas cell. The VUV pulses centered at 161.8 nm reach pulse energies of 1.1 μJ per pulse, while the corresponding pulse duration is measured with a second-order, fringe-resolved autocorrelation scheme to be 18 ± 1 fs on average. Non-resonant, two-photon ionization of Kr and Xe and three-photon ionization of Ne verify the fifth-harmonic pulse intensity and indicate the feasibility of multi-photon VUV pump/VUV probe studies of ultrafast atomic and molecular dynamics. Finally, the extended functionally of the counter-propagating pulse metrology approach is demonstrated by a single-shot VUV pump/VUV probe experiment aiming at the investigation of ultrafast dissociation dynamics of O 2 excited in the Schumann-Runge continuum at 162 nm.

  12. The electronic states of 1,2,3-triazole studied by vacuum ultraviolet photoabsorption and ultraviolet photoelectron spectroscopy, and a comparison with ab initio configuration interaction methods

    DEFF Research Database (Denmark)

    Palmer, Michael H.; Hoffmann, Søren Vrønning; Jones, Nykola C.

    2011-01-01

    The Rydberg states in the vacuum ultraviolet photoabsorption spectrum of 1,2,3-triazole have been measured and analyzed with the aid of comparison to the UV valence photoelectron ionizations and the results of ab initio configuration interaction (CI) calculations. Calculated electronic ionization...... and excitation energies for singlet, triplet valence, and Rydberg states were obtained using multireference multiroot CI procedures with an aug-cc-pVTZ [5s3p3d1f] basis set and a set of Rydberg [4s3p3d3f] functions. Adiabatic excitation energies obtained for several electronic states using coupled...... are the excitations consistent with an f-series....

  13. Fabry-Perot for the Integrated Direct Detection Lidar

    Data.gov (United States)

    National Aeronautics and Space Administration — Develop an etalon front end receiver (FIDDL) and combine it with the Optical Autocovariance Wind Lidar (OAWL) for an integrated direct detection (IDD) wind lidar....

  14. Miniaturized fiber inline Fabry-Perot interferometer for chemical sensing.

    Science.gov (United States)

    2010-01-01

    This paper demonstrates the chemical sensing capability of a miniaturized fiber inline Fabry-Prot sensor fabricated by femtosecond : laser. Its accessible cavity enables the device to measure the refractive index within the cavity. The refractive i...

  15. Enhancement of UV Excited Photoluminescence by Fabry-Perot Microcavity

    Directory of Open Access Journals (Sweden)

    Chunxian Tao

    2015-01-01

    Full Text Available A light-emitting microcavity with the structure of dielectric mirror/phosphor coating/dielectric mirror for the enhancement of PL efficiency excited under UV light was designed and fabricated. The fluorescence emission of Lumogen S0795 coating within microcavity structure is significantly enhanced compared with the coating on bare substrate. The measurement results indicate the possibility of developing front illuminated CCD based on optical resonant cavity for UV-visible imaging with higher sensitivity.

  16. 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

  17. 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.

  18. A tunable, solid, Fabry-Perot etalon for solar seismology

    Science.gov (United States)

    Rust, David M.; Burton, Clive H.; Leistner, Achim J.

    1986-01-01

    A solid etalon has been designed and fabricated from a 50-mm diameter wafer of optical-quality lithium niobate. The finished etalon has a free spectral range of 0.325 nm at 588 nm. The parallel faces are coated with silver, and the central 15-mm aperture of the etalon has a finesse of 18.6. The reflective faces double as electrodes, and application of voltage will shift the passband. This feature was used in a servo circuit to stabilize the passband against temperature and tilt-induced drifts to better than three parts in one billion. Operated in the stabilized mode for day-long sessions, this filter alternately samples the wings of a narrow atomic absorption line in the solar spectrum and produces a signal proportional to velocity on the solar disk. The Fourier transform of this signal yields information on acoustic waves in the solar interior.

  19. VizieR Online Data Catalog: 188 CIV BAL QSOs from SDSS DR7 (He+, 2015)

    Science.gov (United States)

    He, Z.-C.; Bian, W.-H.; Ge, X.; Jiang, X.-L.

    2016-07-01

    In the SDSS DR7, it is found that there are 1080 spectra of 480 CIV BAL QSOs with at least two-epoch observations. In order to identify the variable regions in CIV BAL troughs, we select BAL QSOs with SDSS spectral signal-to-noise ratio (S/N) at r band larger than 10, and redshift more than 1.7. It consists of 188 CIV BAL QSOs with 428 SDSS spectra. (2 data files).

  20. Vacuum ultraviolet photolysis of diclofenac and the effects of its treated aqueous solutions on the proliferation and migratory responses of Tetrahymena pyriformis

    International Nuclear Information System (INIS)

    Arany, Eszter; Láng, Júlia; Somogyvári, Dávid; Láng, Orsolya; Alapi, Tünde; Ilisz, István

    2014-01-01

    The effects of dissolved O 2 , phosphate buffer and the initial concentration of diclofenac on the vacuum ultraviolet photolysis of this contaminant molecule were studied. Besides kinetic measurements, the irradiated, multicomponent samples were characterized via the proliferation and migratory responses (in sublethal concentrations) of the bioindicator eukaryotic ciliate Tetrahymena pyriformis. The results suggest that hydroxyl radicals, hydrogen atoms and hydroperoxyl radicals may all contribute to the degradation of diclofenac. The aromatic by-products of diclofenac were presumed to include a hydroxylated derivative, 1-(8-chlorocarbazolyl)acetic acid and 1-(8-hydroxycarbazolyl)acetic acid. The biological activity of photoexposed samples reflected the chemical transformation of diclofenac and was also dependent on the level of dissolved O 2 . The increase in toxicity of samples taken after different irradiation times did not exceed a factor of two. Our results suggest that the combination of vacuum ultraviolet photolysis with toxicity and chemotactic measurements can be a valuable method for the investigation of the elimination of micropollutants. - Highlights: • The radical-scavenging effect of phosphates seems to be negligible. • Only higher concentrations of HO 2 · contribute to the degradation of diclofenac. • Toxicity of VUV-treated samples decreases with increasing rate of mineralization. • Dissolved O 2 enhances the mineralization of diclofenac by affecting the radical set. • Treated samples retain the chemorepellent character of the parent compound

  1. Vacuum ultraviolet photolysis of diclofenac and the effects of its treated aqueous solutions on the proliferation and migratory responses of Tetrahymena pyriformis

    Energy Technology Data Exchange (ETDEWEB)

    Arany, Eszter [Research Group of Environmental Chemistry, Institute of Chemistry, University of Szeged, H-6720 Szeged, Rerrich Béla tér 1 (Hungary); Láng, Júlia [Department of Genetics, Cell- and Immunobiology, Semmelweis University, H-1089 Budapest, Nagyvárad tér 4 (Hungary); Somogyvári, Dávid [Research Group of Environmental Chemistry, Institute of Chemistry, University of Szeged, H-6720 Szeged, Rerrich Béla tér 1 (Hungary); Láng, Orsolya [Department of Genetics, Cell- and Immunobiology, Semmelweis University, H-1089 Budapest, Nagyvárad tér 4 (Hungary); Alapi, Tünde [Research Group of Environmental Chemistry, Institute of Chemistry, University of Szeged, H-6720 Szeged, Rerrich Béla tér 1 (Hungary); Department of Inorganic and Analytical Chemistry, University of Szeged, H-6720 Szeged, Dóm tér 7 (Hungary); Ilisz, István [Department of Inorganic and Analytical Chemistry, University of Szeged, H-6720 Szeged, Dóm tér 7 (Hungary); and others

    2014-01-01

    The effects of dissolved O{sub 2}, phosphate buffer and the initial concentration of diclofenac on the vacuum ultraviolet photolysis of this contaminant molecule were studied. Besides kinetic measurements, the irradiated, multicomponent samples were characterized via the proliferation and migratory responses (in sublethal concentrations) of the bioindicator eukaryotic ciliate Tetrahymena pyriformis. The results suggest that hydroxyl radicals, hydrogen atoms and hydroperoxyl radicals may all contribute to the degradation of diclofenac. The aromatic by-products of diclofenac were presumed to include a hydroxylated derivative, 1-(8-chlorocarbazolyl)acetic acid and 1-(8-hydroxycarbazolyl)acetic acid. The biological activity of photoexposed samples reflected the chemical transformation of diclofenac and was also dependent on the level of dissolved O{sub 2}. The increase in toxicity of samples taken after different irradiation times did not exceed a factor of two. Our results suggest that the combination of vacuum ultraviolet photolysis with toxicity and chemotactic measurements can be a valuable method for the investigation of the elimination of micropollutants. - Highlights: • The radical-scavenging effect of phosphates seems to be negligible. • Only higher concentrations of HO{sub 2}{sup ·} contribute to the degradation of diclofenac. • Toxicity of VUV-treated samples decreases with increasing rate of mineralization. • Dissolved O{sub 2} enhances the mineralization of diclofenac by affecting the radical set. • Treated samples retain the chemorepellent character of the parent compound.

  2. Measurement of H and H2 populations in-situ in a low-temperature plasma by vacuum-ultraviolet laser-absorption spectroscopy

    International Nuclear Information System (INIS)

    Schlachter, A.S.; Young, A.T.; Stutzin, G.C.; Stearns, J.W.; Doebele, H.G.; Leung, K.N.; Kunkel, W.B.

    1988-12-01

    A new technique, vacuum-ultraviolet laser-absorption spectroscopy, has been developed to quantitatively determine the absolute density of H and H 2 within a plasma. The technique is particularly well suited to measurement in a plasma, where high charged particle and photon background complicate other methods of detection. The high selectivity and sensitivity of the technique allows for the measurement of the rotational-vibrational state distribution of H 2 as well as the translational temperature of the atoms and molecules. The technique has been used to study both pulsed and continuous H/sup /minus// ion-source plasma discharges. H 2 state distributions in a multicusp ''volume'' H/sup /minus// ion- source plasma show a high degree of internal excitation, with levels up to v = 5 and J = 8 being observed. The method is applicable for a very wide range of plasma conditions. Emission measurements from excited states of H are also reported. 17 refs., 9 figs

  3. Dependence of absolute photon flux on infrared absorbance alteration and surface roughness on photoresist polymers irradiated with vacuum ultraviolet photons emitted from HBr plasma

    Science.gov (United States)

    Zhang, Yan; Takeuchi, Takuya; Ishikawa, Kenji; Hayashi, Toshio; Takeda, Keigo; Sekine, Makoto; Hori, Masaru

    2017-12-01

    The absolute fluxes of vacuum ultraviolet (VUV) photons emitted from HBr plasma were analyzed and the effects of VUV photons on a photoresist polymer in ArF-excimer-laser (193 nm) lithography were quantitatively investigated on the basis of the infrared spectra attributed to the C=O region. The spectral peak intensity assigned to the methacrylic acid (MAA) in the photoresist drastically decreased owing to the loss of this monomer caused by the irradiation of VUV photons at dosages below 16 × 1016 photons/cm2. X-ray photoelectron spectroscopy observation showed that the removed monomer moved to the surface and generated volatile products that induced a decrease in film thickness. As a consequence, the surface became rough during the early-stage irradiation at dosages lower than 16 × 1016 photons/cm2 owing to the monomer loss of MAA with volatile product formation and subsequent cross-linking reactions.

  4. 3m Vacuum Ultraviolet Spectrometer with Optical Multichannel Detector; Espectrometro de ultravioleta de vacio de 3m provisto de sistema de deteccion optical multicanal

    Energy Technology Data Exchange (ETDEWEB)

    Martin, P.; Peraza, C.; Blanco, F.; Campos, J.

    1993-07-01

    This paper describes the design and the performance of a normal incidence vacuum ultraviolet spectrometer, for the 300-2400 A spectral range. It is provided with a multichannel detection system. The monochromator is original design and it has been built at CIEMAT. It is equipped with a 3 m concave holographic grating with 2400 grooves/mm. The multichannel detector consists of a windowless double microchannel plate / phosphor screen image intensifier, coupled by fiber optic to a 1024 elements self-scanning linear photodiode array. The output from the array is digitized by a 12-bit analog to digital converter and stored in a computer, for its later analysis. The necessary software to store and display data has been developed. (Author) 18 refs.

  5. Photoluminescence performance of thulium doped Li4SrCa(SiO4)2 under irradiation of ultraviolet and vacuum ultraviolet lights

    International Nuclear Information System (INIS)

    Wang, Zhaofeng; Li, Yezhou; Liu, Xiong; Wei, Xingmin; Chen, Yueling; Zhou, Fei; Wang, Yuhua

    2014-01-01

    Highlights: • A novel blue-emitting phosphor Li 4 SrCa(SiO 4 ) 2 :Tm 3+ was reported. • Li 4 SrCa(SiO 4 ) 2 :Tm 3+ exhibited excellent thermal and irradiation stability. • Li 4 SrCa(SiO 4 ) 2 :Tm 3+ was found to possess high color purity. - Abstract: In this work, we synthesized Tm 3+ doped Li 4 SrCa(SiO 4 ) 2 phosphors and investigated their photoluminescence properties under the excitation of ultraviolet and vacuum ultraviolet lights. The crystal structure analysis and variation of cell parameters confirm that Tm 3+ ions have been successfully doped in the structure of Li 4 SrCa(SiO 4 ) 2 host by occupying the sites of Ca 2+ with the coordination number of 6. The luminescence results suggest that Li 4 SrCa(SiO 4 ) 2 :Tm 3+ is a good blue-emitting phosphor when excited by ultraviolet and vacuum ultraviolet irradiations. In addition, it is observed that there is nearly no degradation for Li 4 SrCa(SiO 4 ) 2 :Tm 3+ after undergoing thermal and irradiation treatments. Possible mechanisms for the luminescence processes are proposed on the basis of the discussion of excitation and emission spectra. In particular, the emission color of Li 4 SrCa(SiO 4 ) 2 :Tm 3+ by excitation of 147 and 172 nm irradiations is very close to the standard blue color, suggesting that it could be potentially applied in plasma display panels and mercury-free fluorescence lamps

  6. Experimental Investigation on Operational Performance of PAFS for CIV Opening Stroke

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Seok; Bae, Byoung-Uhn; Park, Yusun; Kang, Kyoung-Ho [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2015-10-15

    The test facility, ATLAS-PAFS was constructed to experimentally investigate the thermal hydraulic behavior in the primary and secondary systems of the APR+ during a transient when PAFS is actuated. In this study, PAFS-CIV-01 test was performed for validating the cooling rate of the reactor according to the CIV opening stroke at the FLB accident, which was analyzed as the most severe case in the APR+ SSAR (Standard Safety Analysis Report). With an aim of simulating a FLB+CIV accident of the APR+ as realistically as possible, the three-level scaling methodology was taken into account to determine the test conditions of the steady-state and the transient. The main objectives of this test were not only to provide physical insight into the system response of the APR+ during changes of CIV opening stroke but also to produce an integral effect test data to validate a thermal hydraulic safety analysis code. The initial steady-state conditions and the sequence of event in the FLB scenario for the APR+ were successfully simulated with the ATLAS-PAFS facility. The pressure and the temperature gradient of the primary system was reduced as the stroke of the CIV was decreased during the heat removal by PAFS operation. The mean temperature gradient of the core was reduced as the stroke of the CIV was decreased. The cooling rate of the core under 60% stroke (70.4 mm{sup 2}) of the CIV met the criteria. The water in the PCCT was heated up to the saturation condition by the heat transfer from the PCHX tube surface. In PAFS-CIV-01 test, the major sequence of events was ended before the water level decrease in the PCCT. From the present experimental result, it could be concluded that the cooling rate of the core was controlled by the adjustment of the CIV opening stroke when the APR+ PAFS was operating.

  7. Comparison of surface vacuum ultraviolet emissions with resonance level number densities. II. Rare-gas plasmas and Ar-molecular gas mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Boffard, John B., E-mail: jboffard@wisc.edu; Lin, Chun C. [Department of Physics, University of Wisconsin, Madison, Wisconsin 53706 (United States); Wang, Shicong; Wendt, Amy E. [Department of Electrical and Computer Engineering, University of Wisconsin, Madison, Wisconsin 53706 (United States); Culver, Cody [Materials Science Program, University of Wisconsin, Madison, Wisconsin 53706 (United States); Radovanov, Svetlana; Persing, Harold [Applied Materials Inc., Gloucester, Massachusetts 01939 (United States)

    2015-03-15

    Vacuum ultraviolet (VUV) emissions from excited plasma species can play a variety of roles in processing plasmas, including damaging the surface properties of materials used in semiconductor processing. Depending on their wavelength, VUV photons can easily transmit thin upper dielectric layers and affect the electrical characteristics of the devices. Despite their importance, measuring VUV fluxes is complicated by the fact that few materials transmit at VUV wavelengths, and both detectors and windows are easily damaged by plasma exposure. The authors have previously reported on measuring VUV fluxes in pure argon plasmas by monitoring the concentrations of Ar(3p{sup 5}4s) resonance atoms that produce the VUV emissions using noninvasive optical emission spectroscopy in the visible/near-infrared wavelength range [Boffard et al., J. Vac. Sci. Technol., A 32, 021304 (2014)]. Here, the authors extend this technique to other rare-gases (Ne, Kr, and Xe) and argon-molecular gas plasmas (Ar/H{sub 2}, Ar/O{sub 2}, and Ar/N{sub 2}). Results of a model for VUV emissions that couples radiation trapping and the measured rare-gas resonance level densities are compared to measurements made with both a calibrated VUV photodiode and a sodium salicylate fluorescence detection scheme. In these more complicated gas mixtures, VUV emissions from a variety of sources beyond the principal resonance levels of the rare gases are found to contribute to the total VUV flux.

  8. Effects of Irradiation with Ions and Photons in Ultraviolet-Vacuum Ultraviolet Regions on Nano-Surface Properties of Polymers Exposed to Plasmas

    Science.gov (United States)

    Cho, Ken; Takenaka, Kosuke; Setsuhara, Yuichi; Shiratani, Masaharu; Sekine, Makoto; Hori, Masaru

    2012-01-01

    The interactions of ions and photons in ultraviolet (UV) and vacuum ultraviolet (VUV) regions from argon plasmas with polymer surfaces were investigated by of depth analysis of chemical bonding states in the nano-surface layer of poly(ethylene terephthalate) (PET) films via conventional X-ray photoelectron spectroscopy (XPS) and hard X-ray photoelectron spectroscopy (HXPES). The PET films were exposed to argon plasmas by covering the PET films with MgF2 and quartz windows as optical filters to compare the irradiation effects with ions and photons. The conventional XPS results indicated that oxygen functionalities (the C-O bond and the O=C-O bond) were degraded by ion bombardment in the shallower region up to about 10 nm from the surface, whereas the effect of photoirradiation in the UV and VUV regions was insignificant. The HXPES analysis showed that irradiation with ions and photons did not cause serious damage in chemical bonding states in the deeper region up to about 50 nm from the surface.

  9. Quantification of isomerically summed hydrocarbon contributions to crude oil by carbon number, double bond equivalent, and aromaticity using gas chromatography with tunable vacuum ultraviolet ionization.

    Science.gov (United States)

    Nowak, Jeremy A; Weber, Robert J; Goldstein, Allen H

    2018-03-12

    The ability to structurally characterize and isomerically quantify crude oil hydrocarbons relevant to refined fuels such as motor oil, diesel, and gasoline represents an extreme challenge for chromatographic and mass spectrometric techniques. This work incorporates two-dimensional gas chromatography coupled to a tunable vacuum ultraviolet soft photoionization source, the Chemical Dynamics Beamline 9.0.2 of the Advanced Light Source at the Lawrence Berkeley National Laboratory, with a time-of-flight mass spectrometer (GC × GC-VUV-TOF) to directly characterize and isomerically sum the contributions of aromatic and aliphatic species to hydrocarbon classes of four crude oils. When the VUV beam is tuned to 10.5 ± 0.2 eV, both aromatic and aliphatic crude oil hydrocarbons are ionized to reveal the complete chemical abundance of C 9 -C 30 hydrocarbons. When the VUV beam is tuned to 9.0 ± 0.2 eV only aromatic hydrocarbons are ionized, allowing separation of the aliphatic and aromatic fractions of the crude oil hydrocarbon chemical classes in an efficient manner while maintaining isomeric quantification. This technique provides an effective tool to determine the isomerically summed aromatic and aliphatic hydrocarbon compositions of crude oil, providing information that goes beyond typical GC × GC separations of the most dominant hydrocarbon isomers.

  10. Airfoil sampling of a pulsed Laval beam with tunable vacuum ultraviolet (VUV) synchrotron ionization quadrupole mass spectrometry: Application to low--temperature kinetics and product detection

    Energy Technology Data Exchange (ETDEWEB)

    Soorkia, Satchin; Liu, Chen-Lin; Savee, John D; Ferrell, Sarah J; Leone, Stephen R; Wilson, Kevin R

    2011-10-12

    A new pulsed Laval nozzle apparatus with vacuum ultraviolet (VUV) synchrotron photoionization quadrupole mass spectrometry is constructed to study low-temperature radicalneutralchemical reactions of importance for modeling the atmosphere of Titan and the outer planets. A design for the sampling geometry of a pulsed Laval nozzle expansion has beendeveloped that operates successfully for the determination of rate coefficients by time-resolved mass spectrometry. The new concept employs airfoil sampling of the collimated expansion withexcellent sampling throughput. Time-resolved profiles of the high Mach number gas flow obtained by photoionization signals show that perturbation of the collimated expansion by theairfoil is negligible. The reaction of C2H with C2H2 is studied at 70 K as a proof-of-principle result for both low-temperature rate coefficient measurements and product identification basedon the photoionization spectrum of the reaction product versus VUV photon energy. This approach can be used to provide new insights into reaction mechanisms occurring at kinetic ratesclose to the collision-determined limit.

  11. Effect of the methyl substitution on the combustion of two methylheptane isomers: Flame chemistry using vacuum-ultraviolet (VUV) photoionization mass spectrometry

    KAUST Repository

    Selim, Hatem

    2015-04-16

    Alkanes with one or more methyl substitutions are commonly found in liquid transportation fuels, so a fundamental investigation of their combustion chemistry is warranted. In the present work, stoichiometric low-pressure (20 Torr) burner-stabilized flat flames of 2-methylheptane and 3-methylheptane were investigated. Flame species were measured via time-of-flight molecular-beam mass spectrometry, with vacuum-ultraviolet (VUV) synchrotron radiation as the ionization source. Mole fractions of major end-products and intermediate species (e.g., alkanes, alkenes, alkynes, aldehydes, and dienes) were quantified axially above the burner surface. Mole fractions of several free radicals were also measured (e.g., CH3, HCO, C2H3, C3H3, and C3H5). Isomers of different species were identified within the reaction pool by an energy scan between 8 and 12 eV at a distance of 2.5 mm away from the burner surface. The role of methyl substitution location on the alkane chain was determined via comparisons of similar species trends obtained from both flames. The results revealed that the change in CH3 position imposed major differences on the combustion of both fuels. Comparison with numerical simulations was performed for kinetic model testing. The results provide a comprehensive set of data about the combustion of both flames, which can enhance the erudition of both fuels combustion chemistry and also improve their chemical kinetic reaction mechanisms. © 2015 American Chemical Society.

  12. Versatile high-repetition-rate phase-locked chopper system for fast timing experiments in the vacuum ultraviolet and x-ray spectral region

    International Nuclear Information System (INIS)

    Plogmaker, Stefan; Johansson, Erik M. J.; Rensmo, Haakan; Feifel, Raimund; Siegbahn, Hans; Linusson, Per; Eland, John H. D.; Baker, Neville

    2012-01-01

    A novel light chopper system for fast timing experiments in the vacuum-ultraviolet (VUV) and x-ray spectral region has been developed. It can be phase-locked and synchronized with a synchrotron radiation storage ring, accommodating repetition rates in the range of ∼8 to ∼120 kHz by choosing different sets of apertures and subharmonics of the ring frequency (MHz range). Also the opening time of the system can be varied from some nanoseconds to several microseconds to meet the needs of a broad range of applications. Adjusting these parameters, the device can be used either for the generation of single light pulses or pulse packages from a microwave driven, continuous He gas discharge lamp or from storage rings which are otherwise often considered as quasi-continuous light sources. This chopper can be utilized for many different kinds of experiments enabling, for example, unambiguous time-of-flight (TOF) multi-electron coincidence studies of atoms and molecules excited by a single light pulse as well as time-resolved visible laser pump x-ray probe electron spectroscopy of condensed matter in the valence and core level region.

  13. Electronic structure, photoemission spectra, and vacuum-ultraviolet optical spectra of CsPbCl3 and CsPbBr3

    Science.gov (United States)

    Heidrich, K.; Schäfer, W.; Schreiber, M.; Söchtig, J.; Trendel, G.; Treusch, J.; Grandke, T.; Stolz, H. J.

    1981-11-01

    Optical spectra of CsPbCl3 and CsPbBr3 have been measured in the range from 2 to 10 eV and have been combined with ultraviolet-photoemission-spectroscopy (UPS)-measurements at 21.1 and 40.8 eV. A quantitative band calculation is presented, which takes into account anion-anion interaction as well as electronic states of the Cs+ ion. The prominent features of earlier band models and measurements are reestablished through our measurements and calculations, namely that the valence band consists of anionic p functions and Pb 6s functions, the lowest conduction band being Pb 6p type, and the lowest gap occuring at the R point of the Brillouin zone. Inclusion of a further (Cs 6s-type) conduction band, however, is necessary to bring the calculated joint density of states into agreement with vacuum-ultraviolet optical spectra. The calculated densities of states of the valence bands are in quantitative agreement with those deduced from our UPS measurements.

  14. Determination of ionization energies of CnN (n=4-12): Vacuum-ultraviolet (VUV) photoionization experiments and theoretical calculations

    International Nuclear Information System (INIS)

    Kostko, Oleg; Zhou, Jia; Sun, Bian Jian; Lie, Jie Shiuan; Chang, Agnes H.H.; Kaiser, Ralf I.; Ahmed, Musahid

    2010-01-01

    Results from single photon vacuum ultraviolet photoionization of astrophysically relevant CnN clusters, n = 4 - 12, in the photon energy range of 8.0 eV to 12.8 eV are presented. The experimental photoionization efficiency curves, combined with electronic structure calculations, provide improved ionization energies of the CnN species. A search through numerous nitrogen-terminated CnN isomers for n=4-9 indicates that the linear isomer has the lowest energy, and therefore should be the most abundant isomer in the molecular beam. Comparison with calculated results also shed light on the energetics of the linear CnN clusters, particularly in the trends of the even-carbon and the odd-carbon series. These results can help guide the search of potential astronomical observations of these neutral molecules together with their cations in highly ionized regions or regions with a high UV/VUV photon flux (ranging from the visible to VUV with flux maxima in the Lyman-a region) in the interstellar medium.

  15. Occurrence and Global Properties of Narrow CIV lambda 1549 Absorption Lines in Moderate-Redshift Quasars

    DEFF Research Database (Denmark)

    Vestergaard, Marianne

    2003-01-01

    A statistical study is presented of (a) the frequency of narrow CIV lambda 1549 absorption lines in 1.5 ~50%) of narrow CIV absorbers is detected for the radio-quiet and radio-loud quasars, and a constant ~25% of all the quasars, irrespective of radio type display associated CIV absorbers stronger...... than a rest equivalent width of 0.5A. Both radio-quiet and radio-loud quasars with narrow absorption lines have systematically redder continua, especially strongly absorbed objects. There is evidence of inclination dependent dust reddening and absorption for the radio quasars. An additional key result...... is that the most strongly absorbed radio quasars have the largest radio source extent. This result is in stark contrast to a recent study of the low-frequency selected Molonglo survey in which a connection between the strength of the narrow absorbers and the (young) age of the radio source has been proposed...

  16. Flow-modulated comprehensive two-dimensional gas chromatography combined with a vacuum ultraviolet detector for the analysis of complex mixtures.

    Science.gov (United States)

    Zoccali, Mariosimone; Schug, Kevin A; Walsh, Phillip; Smuts, Jonathan; Mondello, Luigi

    2017-05-12

    The present paper is focused on the use of a vacuum ultraviolet absorption spectrometer (VUV) for gas chromatography (GC), within the context of flow modulated comprehensive two-dimensional gas chromatography (FM GC×GC). The features of the VUV detector were evaluated through the analysis of petrochemical and fatty acids samples. Besides responding in a predictable fashion via Beer's law principles, the detector provides additional spectroscopic information for qualitative analysis. Virtually all chemical species absorb and have unique gas phase absorption features in the 120-240nm wavelength range monitored. The VUV detector can acquire up to 90 full range absorption spectra per second, allowing its coupling with comprehensive two-dimensional gas chromatography. This recent form of detection can address specific limitations related to mass spectrometry (e.g., identification of isobaric and isomeric species with very similar mass spectra or labile chemical compounds), and it is also able to deconvolute co-eluting peaks. Moreover, it is possible to exploit a pseudo-absolute quantitation of analytes based on pre-recorded absorption cross-sections for target analytes, without the need for traditional calibration. Using this and the other features of the detector, particular attention was devoted to the suitability of the FM GC×GC-VUV system toward qualitative and quantitative analysis of bio-diesel fuel and different kinds of fatty acids. Satisfactory results were obtained in terms of tailing factor (1.1), asymmetry factor (1.1), and similarity (average value 97%), for the FAMEs mixtures analysis. Copyright © 2017 Elsevier B.V. All rights reserved.

  17. A Deep Narrowband Imaging Search for CIV and He II Emission from Ly$\\alpha$ Blobs

    OpenAIRE

    Battaia, Fabrizio Arrigoni; Yang, Yujin; Hennawi, Joseph F.; Prochaska, J. Xavier; Matsuda, Yuichi; Yamada, Toru; Hayashino, Tomoki

    2014-01-01

    We conduct a deep narrow-band imaging survey of 13 Ly$\\alpha$ blobs (LABs) located in the SSA22 proto-cluster at z~3.1 in the CIV and HeII emission lines in an effort to constrain the physical process powering the Ly$\\alpha$ emission in LABs. Our observations probe down to unprecedented surface brightness limits of 2.1 $-$ 3.4 $\\times$ 10$^{-18}$ erg s$^{-1}$ cm$^{-2}$ arcsec$^{-2}$ per 1 arcsec$^2$ aperture (5$\\sigma$) for the HeII$\\lambda$1640 and CIV$\\lambda$1549 lines, respectively. We do...

  18. Laboratory experiments on the magnetic field and neutral density limits on CIV interaction

    International Nuclear Information System (INIS)

    Axnaes, I.; Brenning, N.

    1990-03-01

    Laboratory experiments are reported which determine the magnetic field and neutral density limit for Critical Ionization Velocity (CIV) interaction in the impact configuration. A combination of microwave interferometry and spectroscopy has been used to measure how the electron energy distribution varies with the neutral density and the magnetic field strength. The efficiency of the CIV process is evaluated in terms of the efficiency factor η of energy transfer to the electron. This efficiency is studied as function of the ratio V A /V 0 between the Alfven velocity and the plasma stream velocity and the ratio ν i /ω gi between the ionization frequency and the ion gyro frequency. With other parameters kept constant, V A /V 0 is proportional to the square root of the magnetic field, while ν i /ω gi is proportional to the neutral density. We have found that these two dimensionless parameters are coupled in such a fashion that a stronger magnetic field can compensate for a lower neutral density. For our strongest magnetic field, corresponding to V A /V 0 = 4, CIV interaction is found to occur for a comparatively low value ν i /ω gi ∼ 0.1. For V A /V 0 = 1, we found a clear absence of CIV interaction even for ν i /ω gi approaching unity. (authors)

  19. Narrow CIV lambda 1549A Absorption Lines in Moderate-Redshift Quasars

    DEFF Research Database (Denmark)

    Vestergaard, Marianne

    2002-01-01

    A large, high-quality spectral data base of well-selected, moderate-redshift radio-loud and radio-quiet quasars is used to characterize the incidence of narrow associated CIV lambda 1549 absorption, and how this may depend on some quasar properties, including radio-type. Preliminary results...

  20. Vibrational autoionization of state-selective jet-cooled methanethiol (CH3SH) investigated with infrared vacuum-ultraviolet photoionization

    Energy Technology Data Exchange (ETDEWEB)

    Xie, Min; Sen, Zhitao; Pratt, S. T.; Lee, Yuan-Pern

    2017-11-21

    Vibrational autoionization of Rydberg states provides key information about nonadiabatic processes above an ionization threshold. We employed time-of-flight mass detection of CH3SH+ to record vibrational-state selective photo-ionization efficiency (PIE) spectra of jet-cooled methanethiol (CH3SH) on exciting CH3SH to a specific vibrationally excited state with an infrared (IR) laser, followed by excitation with a tunable laser in the vacuum-ultraviolet (VUV) region for ionization. Autoionizing Rydberg states assigned to the ns, np, nd and nf series are identified. When IR light at 2601 (ν3, SH stretching mode) and 2948 cm-12, CH3 symmetric stretching mode) was employed, the Rydberg series converged to the respective vibrationally excited (ν3 and ν2) states of CH3SH+. When IR light at 3014 cm-1 (overlapped ν19, CH3 antisymmetric stretching and CH2 antisymmetric stretching modes) was employed, two converging limits towards vibrationally excited states (ν1 and ν9) of CH3SH+ were observed. In contrast, when IR light at 2867 cm-1 (2ν10, overtone of CH3 deformation mode) and 2892 cm-1 (2ν4, overtone of CH2 scissoring mode) was employed, both Δν = -1 and Δν = -2 ionization transitions were observed; there is evidence for direct ionization from the initial state into the CH3SH+ (v4+ = 1) continuum. In all observed IR-VUV-PIE spectra, the ns and nd series show intensity greater than the other Rydberg series, which is consistent with the fact that the highest-occupied molecular orbital of CH3SH is a p-like lone pair orbital on the S atom. The quantum yields for autoionization of various vibrational excited states are discussed.

  1. The electronic states of 1,2,4-triazoles: A study of 1H- and1-methyl-1,2,4-triazole by vacuum ultraviolet photoabsorption and ultraviolet photoelectron spectroscopy and a comparison with ab initio configuration interaction computations

    DEFF Research Database (Denmark)

    Palmer, Michael H.; Camp, Philip J.; Hoffmann, Søren Vrønning

    2012-01-01

    The first vacuum ultraviolet absorption spectrum of a 1,2,4-triazole has been obtained and analyzed in detail, with assistance from both an enhanced UV photoelectron spectroscopic study and ab initio multi-reference multi-root configuration interaction procedures. For both 1H- and 1-methyl-1......,2,4-triazoles, the first ionization energy bands show complex vibrational structure on the low-energy edges of otherwise unstructured bands. Detailed analysis of these bands confirms the presence of three ionized states. The 6–7 eV VUV spectral region shows an unusual absorption plateau, which is interpreted...

  2. VizieR Online Data Catalog: SDSS/BOSS/TDSS CIV BAL quasars (Grier+, 2016)

    Science.gov (United States)

    Grier, C. J.; Brandt, W. N.; Hall, P. B.; Trump, J. R.; Filiz, Ak N.; Anderson, S. F.; Green, P. J.; Schneider, D. P.; Sun, M.; Vivek, M.; Beatty, T. G.; Brownstein, J. R.; Roman-Lopes, A.

    2016-08-01

    We began with the 2005 targets from the BAL catalog of Gibson et al. (2009, J/ApJ/692/758), which were observed by SDSS and targeted for additional observations with Baryon Oscillation Spectroscopic Survey (BOSS; Eisenstein et al. 2011AJ....142...72E; Dawson et al. 2013AJ....145...10D) and Time Domain Spectroscopic Survey (TDSS; Morganson et al. 2015ApJ...806..244M). We then searched for BOSS and TDSS observations of these targets as of 2015 June 30, identifying 172 targets that were observed by all three surveys. We restricted the redshift range of our sample to 1.5CIV region and to a signal-to-noise ratio (S/N1700) equal to or greater than 6. See section 2.1 for further details. (1 data file).

  3. 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

  4. Millimeter Wave Spectroscopy in a Semi-Confocal Fabry-Perot Cavity

    Science.gov (United States)

    Drouin, Brian; Tang, Adrian; Reck, Theodore J.; Nemchick, Deacon J.; Cich, Matthew J.; Crawford, Timothy J.; Raymond, Alexander W.; Chang, M.-C. Frank; Kim, Rod M.

    2017-06-01

    A new generation of CMOS circuits operating at 89-104 GHz with improved output power and pulse switch isolation have enhanced the performance of the miniaturized pulsed-echo Fourier transform spectrometer under development for planetary exploration at the Jet Propulsion laboratory. Additional progress has been made by creating a waveguide-fed structure for the novel planar coupler design. This structure has enabled characterization of each component in the system and enabled spectroscopy to be done with conventional millimeter hardware that enables (1) direct comparisons to the CMOS components, (2) enhanced bandwidth of 74-109 GHz, and (3) amplification of the transmitter prior to cavity injection. We have now demonstrated the technique with room temperature detections on multiple species including N_2O, OCS, CH_3CN, CH_3OH, CH_3NH_2, CH_3CHO, CH_3Cl, HDO, D_2O, CH_3CH_2CN and CH_3CH_2OH. Of particular interest to spectroscopic work in the millimeter range is the ongoing incorporation of a ΔΣ radio-frequency source into the millimeter-wave lock-loop - this has improved the phase-noise of the tunable CMOS transceiver to better than the room-temperature Doppler limit and provides a promising source for general use that may replace the high end microwave synthesizers. We are in the process of building a functional interface to the various subsystems. We will present a trade-space study to determine the optimal operating conditions of the pulse-echo system.

  5. Rugged Low Temperature Actuators for Tunable Fabry Perot Optical Filters, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — Why are rugged, low temperature actuator materials important? By themselves, they are useless; however, when fabricated into thin films and integrated into optical...

  6. 1.5 MU M Fabry-Perot Microcavities Based on Hydrogenated Silicon and Related Materials

    Science.gov (United States)

    2001-06-01

    limited by sensitivity of InGaAs photodiode. A sharp 1.54 jtm peak corresponds to a resonant mode of the MC. 167 168 Microcavity and Photonic Cristal A C B...transmission spectra are found to be close to each other in agreement with our theoretical analysis. 170 Microcavity and Photonic Cristal 2. Conclusions In

  7. Shot Noise in Gravitational-Wave Detectors with Fabry-Perot Arms

    OpenAIRE

    Lyons, Torrey T.; Regehr, Martin W.; Raab, Frederick J.

    2000-01-01

    Shot-noise-limited sensitivity is calculated for gravitational-wave interferometers with Fabry–Perot arms, similar to those being installed at the Laser Interferometer Gravitational-Wave Observatory (LIGO) and the Italian–French Laser Interferometer Collaboration (VIRGO) facility. This calculation includes the effect of nonstationary shot noise that is due to phase modulation of the light. The resulting formula is experimentally verified by a test interferometer with suspended mirrors in the ...

  8. Synchronization dynamics of two nanomechanical membranes within a Fabry-Perot cavity

    Science.gov (United States)

    Bemani, F.; Motazedifard, Ali; Roknizadeh, R.; Naderi, M. H.; Vitali, D.

    2017-08-01

    Spontaneous synchronization is a significant collective behavior of weakly coupled systems. Due to their inherent nonlinear nature, optomechanical systems can exhibit self-sustained oscillations which can be exploited for synchronizing different mechanical resonators. In this paper, we explore the synchronization dynamics of two membranes coupled to a common optical field within a cavity, and pumped with a strong blue-detuned laser drive. We focus on the system quantum dynamics in the parameter regime corresponding to synchronization of the classical motion of the two membranes. With an appropriate definition of the phase difference operator for the resonators, we study synchronization in the quantum case through the covariance matrix formalism. We find that for sufficiently large driving, quantum synchronization is robust with respect to quantum fluctuations and to thermal noise up to not too large temperatures. Under synchronization, the two membranes are never entangled, while quantum discord behaves similarly to quantum synchronization, that is, it is larger when the variance of the phase difference is smaller.

  9. Transient-fiber-Bragg grating spectra in self-swept Fabry-Perot fiber lasers

    OpenAIRE

    Peterka, P. (Pavel); Honzátko, P. (Pavel); Koška, P. (Pavel); Podrazký, O. (Ondřej); Kašík, I. (Ivan)

    2015-01-01

    Fiber laser instabilities may significantly influence fiber laser performance. Recently, we have shown that the self-Q-switching instability mode can evolve from the so-called self-induced laser line sweeping (SLLS). The SLLS effect is characterized by quasiperiodic laser line drift in a relatively broad wavelength interval. The SLLS is caused by standing-wave in the cavity. Such regular standing waves series create also significant reflection grating through resonant index change of the rare...

  10. Theoretical analysis of laser-locked spectroscopy employing a confocal Fabry-Perot cavity

    International Nuclear Information System (INIS)

    Dong, Lei; Li, Linfeng; Ma, Weiguang; Zhang, Lei; Yin, Wangbao; Jia, Suotang

    2006-01-01

    A theoretical analysis of laser-locked enhanced absorption spectroscopy employing a confocal Fary-Perot cavity (CFPC) is presented. The signal-to-noise ratio and the minimum detectable absorbance, which are limited by either the shot noise or the amplitude noise due to the loose laser lock loop, are also discussed in detail. The results show that the effective absorption path length of a CFPC configuration is the same as that of the conventional nonconfocal Fary-Perot cavity configuration, with the CFPC configuration being more convenient to align without deliberate mode matching. Thus, the CFPC configuration should greatly simplify the complications of conventional laser-locked spectroscopy.

  11. Novel Fourier transform infrared spectrometer architecture based on cascaded Fabry-Perot interferometers

    Science.gov (United States)

    Eltagoury, Yomna M.; Sabry, Yasser M.; Khalil, Diaa A.

    2016-03-01

    In this work, we present a novel architecture for Fourier transform spectrometers based on cascaded low-finesse FP interferometers. One of the interferometers has fixed path length while the second is a scanning one using a relatively large stroke electrostatic comb-drive actuator. The fixed interferometer results in a spectrum modulation and, hence, a shifted version of the interferogram away from the point of the zero spacing between the two mirrors. The shifted interferogram can then be used with the Fourier transform algorithm to obtain the spectrum of the measured light. This cascaded FP configuration results in a simple arrangement of mirrors on a line, which makes it much tolerant to misalignment errors. The proposed configuration is implemented using the MEMS DRIE technology on an SOI wafer with a simple MEMS process flow without metallization or dielectric coating of the vertical optical surface. The fabricated compact structure is measured with both a laser source with narrow spectrum at 1550 nm and a wide spectrum source composed of an SLED and the ASE of a semiconductor optical amplifier source. The obtained results validate the concept of the new configuration.

  12. Ultra-Precise Measurement of Distance by Fabry-Perot Resonator

    Czech Academy of Sciences Publication Activity Database

    Číp, Ondřej; Petrů, František; Lazar, Josef; Buchta, Zdeněk

    T118, - (2005), s. 45-47 ISSN 0031-8949 R&D Projects: GA ČR(CZ) GP102/02/P122 Keywords : length measurements * laser interferometer * optical resonator Subject RIV: BH - Optics, Masers, Lasers Impact factor: 0.661, year: 2004

  13. Electronic excitation of carbonyl sulphide (COS) by high-resolution vacuum ultraviolet photoabsorption and electron-impact spectroscopy in the energy region from 4 to 11 eV

    Energy Technology Data Exchange (ETDEWEB)

    Limão-Vieira, P., E-mail: plimaovieira@fct.unl.pt [Laboratório de Colisões Atómicas e Moleculares, CEFITEC, Departamento de Física, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516 Caparica (Portugal); Department of Physics, Sophia University, Tokyo 102-8554 (Japan); Department of Physical Sciences, The Open University, Walton Hall, Milton Keynes MK7 6AA (United Kingdom); Ferreira da Silva, F.; Almeida, D. [Laboratório de Colisões Atómicas e Moleculares, CEFITEC, Departamento de Física, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516 Caparica (Portugal); Hoshino, M.; Tanaka, H. [Department of Physics, Sophia University, Tokyo 102-8554 (Japan); Mogi, D. [Development and Marketing Department, New Products Development Division, Kanto Denka, Kogyo Co., Ltd., Chiyoda-ku, Tokyo 101-0063 (Japan); Tanioka, T. [Shibukawa Development Research Laboratory, New Products Development Division, Kanto Denka Kogyo Co., Ltd., Shibukawa City, Gunma 377-8513 (Japan); Mason, N. J. [Department of Physical Sciences, The Open University, Walton Hall, Milton Keynes MK7 6AA (United Kingdom); Hoffmann, S. V. [ISA, Department of Physics and Astronomy, Aarhus University, Ny Munkegade 120, DK-8000 Århus C (Denmark); Hubin-Franskin, M.-J.; Delwiche, J. [Départment de Chimie, Université de Liège, Institut de Chimie-Bât. B6C, allée de la Chimie 3, B-4000 Liège 1 (Belgium)

    2015-02-14

    The electronic state spectroscopy of carbonyl sulphide, COS, has been investigated using high resolution vacuum ultraviolet photoabsorption spectroscopy and electron energy loss spectroscopy in the energy range of 4.0–10.8 eV. The spectrum reveals several new features not previously reported in the literature. Vibronic structure has been observed, notably in the low energy absorption dipole forbidden band assigned to the (4π←3π) ({sup 1}Δ←{sup 1}Σ{sup +}) transition, with a new weak transition assigned to ({sup 1}Σ{sup −}←{sup 1}Σ{sup +}) reported here for the first time. The absolute optical oscillator strengths are determined for ground state to {sup 1}Σ{sup +} and {sup 1}Π transitions. Based on our recent measurements of differential cross sections for the optically allowed ({sup 1}Σ{sup +} and {sup 1}Π) transitions of COS by electron impact, the optical oscillator strength f{sub 0} value and integral cross sections (ICSs) are derived by applying a generalized oscillator strength analysis. Subsequently, ICSs predicted by the scaling are confirmed down to 60 eV in the intermediate energy region. The measured absolute photoabsorption cross sections have been used to calculate the photolysis lifetime of carbonyl sulphide in the upper stratosphere (20–50 km)

  14. The electronic states of 1,2,4-triazoles: A study of 1H- and 1-methyl-1,2,4-triazole by vacuum ultraviolet photoabsorption and ultraviolet photoelectron spectroscopy and a comparison with ab initio configuration interaction computations

    Science.gov (United States)

    Palmer, Michael H.; Camp, Philip J.; Hoffmann, Søren Vrønning; Jones, Nykola C.; Head, Ashley R.; Lichtenberger, Dennis L.

    2012-03-01

    The first vacuum ultraviolet absorption spectrum of a 1,2,4-triazole has been obtained and analyzed in detail, with assistance from both an enhanced UV photoelectron spectroscopic study and ab initio multi-reference multi-root configuration interaction procedures. For both 1H- and 1-methyl-1,2,4-triazoles, the first ionization energy bands show complex vibrational structure on the low-energy edges of otherwise unstructured bands. Detailed analysis of these bands confirms the presence of three ionized states. The 6-7 eV VUV spectral region shows an unusual absorption plateau, which is interpreted in terms of the near degeneracy of the first two ionization energies, leading to a pseudo Jahn-Teller effect. The "fingerprint" of the ionization spectrum yields band origins for several Rydberg states. The configuration interaction study shows that although the equilibrium structure for the first cation is effectively planar, the second cation shows significant twisting of the ring system. Some calculated singlet electronic states also show skeletal twisting in which the ring C-H is substantially out of plane.

  15. Vacuum ultraviolet spectra from highly ionized oxygen

    International Nuclear Information System (INIS)

    Sjoedin, R.; Pihl, J.; Hallin, R.; Lindskog, J.; Marelius, A.; Sharma, K.

    1976-03-01

    Transitions in Li-like, He-like and H-like oxygen have been observed in the wavelength region 350-1150 A. A number of lines assigned as transitions in the doubly excited quartet system of O VI are reported. Lifetimes for the 4f 3 F term in O VII, 4f 2 F, 4d 2 D, 4p 2 P terms and for the 2s4f 4 F term in O VI have been measured to 13+-6 ps, 48+-3 ps, 29+-4 ps, 73+-8 ps and 47+-4 ps respectively. (Auth.)

  16. Polarization Measurements in the Vacuum Ultraviolet

    Science.gov (United States)

    West, E. A.; Kobayashi, K.; Noble, M.

    2005-01-01

    This paper will describe the VUV polarization testing of the NSSTC Solar Ultraviolet Magnetograph (SUMI) optics. SUMI is being developed for a sounding rocket payload to prove the feasibility of making magnetic field measurements in the transition region. This paper will cover the polarization properties of the VUV calibration polarizers, the instrumental polarization of the VUV chamber, SUMI's toroidal varied-line-space gratings and the SUMI polarimeter.

  17. Rovibrationally selected ion-molecule collision study using the molecular beam vacuum ultraviolet laser pulsed field ionization-photoion method: charge transfer reaction of N2(+)(X 2Σg+; v+ = 0-2; N+ = 0-9) + Ar.

    Science.gov (United States)

    Chang, Yih Chung; Xu, Yuntao; Lu, Zhou; Xu, Hong; Ng, C Y

    2012-09-14

    We have developed an ion-molecule reaction apparatus for state-selected absolute total cross section measurements by implementing a high-resolution molecular beam vacuum ultraviolet (VUV) laser pulsed field ionization-photoion (PFI-PI) ion source to a double-quadrupole double-octopole ion-guide mass spectrometer. Using the total cross section measurement of the state-selected N(2)(+)(v(+), N(+)) + Ar charge transfer (CT) reaction as an example, we describe in detail the design of the VUV laser PFI-PI ion source used, which has made possible the preparation of reactant N(2)(+)(X (2)Σ(g)(+), v(+) = 0-2, N(+) = 0-9) PFI-PIs with high quantum state purity, high intensity, and high kinetic energy resolution. The PFI-PIs and prompt ions produced in the ion source are shown to have different kinetic energies, allowing the clean rejection of prompt ions from the PFI-PI beam by applying a retarding potential barrier upstream of the PFI-PI source. By optimizing the width and amplitude of the pulsed electric fields employed to the VUV-PFI-PI source, we show that the reactant N(2)(+) PFI-PI beam can be formed with a laboratory kinetic energy resolution of ΔE(lab) = ± 50 meV. As a result, the total cross section measurement can be conducted at center-of-mass kinetic energies (E(cm)'s) down to thermal energies. Absolute total rovibrationally selected cross sections σ(v(+) = 0-2, N(+) = 0-9) for the N(2)(+)(X (2)Σ(g)(+); v(+) = 0-2, N(+) = 0-9) + Ar CT reaction have been measured in the E(cm) range of 0.04-10.0 eV, revealing strong vibrational enhancements and E(cm)-dependencies of σ(v(+) = 0-2, N(+) = 0-9). The thermochemical threshold at E(cm) = 0.179 eV for the formation of Ar(+) from N(2)(+)(X; v(+) = 0, N(+)) + Ar was observed by the measured σ(v(+) = 0), confirming the narrow ΔE(cm) spread achieved in the present study. The σ(v(+) = 0-2; N(+)) values obtained here are compared with previous experimental and theoretical results. The theoretical predictions

  18. Quasar Massive Ionized Outflows Traced by CIV λ1549 and [OIII]λλ4959,5007

    Energy Technology Data Exchange (ETDEWEB)

    Marziani, Paola [National Institute for Astrophysics, Osservatorio Astronomico di Padova, Rome (Italy); Negrete, C. Alenka; Dultzin, Deborah [Instituto de Astronomía, Universidad Nacional Autonoma de Mexico, Mexico City (Mexico); Martínez-Aldama, Mary L.; Del Olmo, Ascensión [Instituto de Astrofísica de Andalucía (CSIC), Granada (Spain); D' Onofrio, Mauro [Dipartimento di Fisica e Astronomia, Università di Padova, Padova (Italy); Stirpe, Giovanna M., E-mail: paola.marziani@oapd.inaf.it [Osservatorio Astronomico di Bologna (INAF), Bologna (Italy)

    2017-09-27

    The most luminous quasars (with bolometric luminosities are ≳ 10{sup 47} erg/s) show a high prevalence of CIV λ1549 and [OIII]λλ4959,5007 emission line profiles with strong blueshifts. Blueshifts are interpreted as due to Doppler effect and selective obscuration, and indicate outflows occurring over a wide range of spatial scales. We found evidence in favor of the nuclear origin of the outflows diagnosed by [OIII]λλ4959,5007. The ionized gas mass, kinetic power, and mechanical thrust are extremely high, and suggest widespread feedback effects on the host galaxies of very luminous quasars, at cosmic epochs between 2 and 6 Gyr from the Big Bang. In this mini-review we summarize results obtained by our group and reported in several major papers in the last few years with an eye on challenging aspects of quantifying feedback effects in large samples of quasars.

  19. Quasar Massive Ionized Outflows Traced by CIV λ1549 and [OIII]λλ4959,5007

    Directory of Open Access Journals (Sweden)

    Paola Marziani

    2017-09-01

    Full Text Available The most luminous quasars (with bolometric luminosities are ≳ 1047 erg/s show a high prevalence of CIV λ1549 and [OIII]λλ4959,5007 emission line profiles with strong blueshifts. Blueshifts are interpreted as due to Doppler effect and selective obscuration, and indicate outflows occurring over a wide range of spatial scales. We found evidence in favor of the nuclear origin of the outflows diagnosed by [OIII]λλ4959,5007. The ionized gas mass, kinetic power, and mechanical thrust are extremely high, and suggest widespread feedback effects on the host galaxies of very luminous quasars, at cosmic epochs between 2 and 6 Gyr from the Big Bang. In this mini-review we summarize results obtained by our group and reported in several major papers in the last few years with an eye on challenging aspects of quantifying feedback effects in large samples of quasars.

  20. Measurement of the electric field pattern of a Fabry-Perot resonator used in quasi-optical gyrotrons

    International Nuclear Information System (INIS)

    Roulin, M.; Tran, M.Q.; Hogge, J.P.

    1992-10-01

    The field pattern of the resonator used in a quasi-optical gyrotron operating in the millimetre wave range is measured. Two resonators are studied: one composed of a spherical mirror and an ellipsoidal grating and the other symmetric using two mirrors with annular slots. The measurements indicate that the electric field distribution is gaussian, in spite of the complex geometry of the resonator, and thus provide an experimental basis for the assumption often used to compute the efficiency of quasi-optical gyrotrons. (author) 9 figs., 8 refs

  1. Determination of Absolute Plate Spacing for the Fabry-Perot Subassembly of the Thermosphere Imager for Global Observations

    Data.gov (United States)

    National Aeronautics and Space Administration — We will rad test a commercial Capacitive to Digital Converter for potential use in geostationary orbit, develop an algorithm to determine absolute spacing using a...

  2. Influence of intra-cavity loss on transmission characteristics of fiber Bragg grating Fabry-Perot cavity

    Science.gov (United States)

    Wang, Di; Ding, Meng; Pi, Hao-Yang; Li, Xuan; Yang, Fei; Ye, Qing; Cai, Hai-Wen; Wei, Fang

    2018-02-01

    Not Available Project supported by the National Natural Science Foundation of China (Grant Nos. 61405212, 61377062, 61405218, and 61775225) and Scientific Innovation Fund of Chinese Academy of Sciences (Grant No. CXJJ-17S010).

  3. High-resolution and Fast-response Fiber-optic Temperature Sensor Using Silicon Fabry-Perot Cavity

    Science.gov (United States)

    2015-03-23

    sensor using silicon Fabry -Pérot cavity 0601153N 73-4951-05-5 Guigen Liu, Ming Han, and Weilin Hou Naval Research Laboratory Oceanography Division...VA 22203-1995 ONR Approved for public release, distribution is unlimited. We report a fiber-optic sensor based on a silicon Fabry -Pérot cavity...silicon Fabry -Pérot cavity Guigen Liu,1 Ming Han,1,* and Weilin Hou2 1Department of Electrical Engineering, University of Nebraska-Lincoln, Lincoln

  4. MEMS-based Optic Fiber Fabry-Perot Sensor for Underwater Acoustic Measurement with A Wavelength-switched System

    Science.gov (United States)

    Xia, J.; Y Wang, F.; Luo, H.; Hu, Y. M.; Xiong, S. D.

    2017-12-01

    In this paper, a MEMS-based extrinsic Farby-Perot Interferometric (EFPI) acoustic pressure acoustic sensor is presented. The diaphragm structure is used as the second reflected surface, and the sensitive surface to acoustic pressure. A wavelength-switched phase demodulation system for EFPI sensors is used for acoustic signal recovery. The modified phase demodulation system has been demonstrated to recover the signal to a stable intensity fluctuation level of ±0.5 dB at the test frequency of 2000 Hz. In the test depth of 50cm, the sensor has a resonant frequency of 3.7 kHz, a flat frequency range of 10-800Hz, and a corresponding acoustic pressure sensitivity of -159 dB re. 1/μPa.

  5. Theoretical Study of an Actively Mode-Locked Fiber Laser Stabilized by an Intracavity Fabry-Perot Etalon: Linear Regime

    Science.gov (United States)

    2007-07-01

    competition without a significant ncrease in the pulse duration. . MATHEMATICAL MODEL FOR THE ASER ur mathematical model of the laser is similar to...to he case 1=0. The increase in the parameter P̂ yields an ncrease in the pulse duration by a factor of approxi- ately 10. It is possible to...etalon and it increases as the finesse of the etalon ncreases . Therefore, in a laser with an etalon, the total ispersion is determined by the parameter D̂

  6. Design of 10-to-40 GHz and higer pulse-rate multiplication by means of coupled Fabry-Perot Resonators

    Czech Academy of Sciences Publication Activity Database

    Slavík, Radan; LaRochelle, S.

    2005-01-01

    Roč. 247, 4/6 (2005), s. 307-312 ISSN 0030-4018 Institutional research plan: CEZ:AV0Z20670512 Keywords : optical fibre communication * modelling Subject RIV: BH - Optics, Masers, Lasers Impact factor: 1.456, year: 2005

  7. X-ray Resonance in Crystal Cavities--Realization of Fabry-Perot Resonator for Hard X-rays

    OpenAIRE

    Chang, S. -L.; Stetsko, Yu. P.; Tang, M. -T.; Lee, Y. -R.; Sun, W. -H.; Yabashi, M.; Ishikawa, T.

    2004-01-01

    X-ray back diffraction from monolithic two silicon crystal plates of 25--150 um thick and a 40--150 um gap using synchrotron radiation of energy resolution deltaE=0.36 meV at 14.4388 keV shows clearly resonance fringes inside the energy gap and the total-reflection range for the (12 4 0) reflection. This cavity resonance results from the coherent interaction between the X-ray wavefields generated by the two plates with a gap smaller than the X-ray coherence length. This finding opens up new o...

  8. Quantum yields of decomposition and homo-dimerization of solid L-alanine induced by 7.2 eV Vacuum ultraviolet light irradiation: an estimate of the half-life of L-alanine on the surface of space objects.

    Science.gov (United States)

    Izumi, Yudai; Nakagawa, Kazumichi

    2011-08-01

    One of the leading hypotheses regarding the origin of prebiotic molecules on primitive Earth is that they formed from inorganic molecules in extraterrestrial environments and were delivered by meteorites, space dust and comets. To evaluate the availability of extraterrestrial amino acids, it is necessary to examine their decomposition and oligomerization rates as induced by extraterrestrial energy sources, such as vacuum ultraviolet (VUV) and X-ray photons and high energy particles. This paper reports the quantum yields of decomposition ((8.2 ± 0.7) × 10(-2) photon(-1)) and homo-dimerization ((1.2 ± 0.3) × 10(-3) photon(-1)) and decomposition of the dimer (0.24 ± 0.06 photon(-1)) of solid L-alanine (Ala) induced by VUV light with an energy of 7.2 eV. Using these quantum yields, the half-life of L-Ala on the surface of a space object in the present earth orbit was estimated to be about 52 days, even when only photons with an energy of 7.2 eV emitted from the present Sun were considered. The actual half-life of solid L-Ala on the surface of a space object orbit around the present day Earth would certainly be much shorter than our estimate, because of the added effect of photons and particles of other energies. Thus, we propose that L-Ala needs to be shielded from solar VUV in protected environments, such as the interior of a meteorite, within a time scale of days after synthesis to ensure its arrival on the primitive Earth.

  9. Effects of Vacuum Ultraviolet Radiation on Thin Polyimide Films Evaluated

    Science.gov (United States)

    Dever, Joyce A.; Messer, Russell K.; Powers, Charles; Townsend, Jacqueline A.; Wooldridge, Eve

    2001-01-01

    NASA anticipates launching the Next Generation Space Telescope (NGST) mission-- whose purpose is to examine the origins of our universe by making measurements in the infrared portion of the spectrum--in 2009. So that the telescope can operate at very low temperatures (less than 100 K), a halo orbit about the second Lagrangian point (L2) is being considered because it is far from Earth and its reflected sunlight. The Sun-Earth L2 point is located 1.53 10(exp 6) km from the Earth in the direction away from the Sun. This mission presents new challenges in many areas of technology, including the development of a multilayer insulation sunshield for the telescope. This sunshield is required to be large (proposed dimensions of approximately 33 by 14 m), storable, deployable, and lightweight. In addition, its polymer film layers must be seamable, foldable, and resistant to tearing and creep, with low outgassing. The sunshield must maintain its structural integrity and its Sun-facing side must maintain a low solar absorptance to thermal emittance ratio (alpha/epsilon) over the planned 10-yr mission duration including over 80,000 hr facing constant sunlight.

  10. Vacuum ultraviolet light generation applications to resonance ionization spectroscopy

    International Nuclear Information System (INIS)

    Payne, M.G.

    1986-08-01

    A theoretical discussion is given for sum mixing with unfocused Gaussian beams. The four-wave sum and difference mixing are carried out in two ''active'' gases: xenon and krypton. In the negatively dispersive regions buffer gases are added to achieve phase matching. 6 refs., 2 figs

  11. Vacuum ultraviolet spectroscopy of some hydrocarbons by electron impact technique

    International Nuclear Information System (INIS)

    Azevedo e Souza, A.C. de.

    1985-07-01

    A detailed description of the construction and operation of the electron impact spectrometer of the Electron Impact Laboratory at the Chemistry Institute of Federal University of Rio de Janeiro are presented. The main characteristics of this spectrometer are: incident energy from 0.5 to 3.0 KeV; angular range from -60 0 to + 60 0 ; energy loss from 0 to 500 eV; energy resolution from 0.5 to 2.5 eV and; electron velocity analyser equal to electrostatic (Mollenstedt type. The data acquisition system is based on a microcomputer Motorola; recently an APPLE II system has been incorporated to the spectrometer. Electron energy loss spectra for the nitrogen molecule as well as for some hydrocarbons (C 2 H 6 , C 2 H 4 , C 2 H 2 ) have been obtained. The data were converted into double differential cross sections and generalized oscillator strenghts. (author) [pt

  12. Vacuum ultraviolet photoionization and photodissociation of polyatomic molecules and radicals

    Energy Technology Data Exchange (ETDEWEB)

    Ng, C.Y. [Iowa State Univ., Ames (United States)

    1993-12-01

    In the past decade, tremendous progress has been made in understanding the photodissociation (PD) dynamics of triatomic molecules. However, the PD study of radicals, especially polyatomic radicals, has remained essentially an unexplored research area. Detailed state-to-state PD cross sections for radicals in the UV and VUV provide challenges not only for dynamical calculations, but also for ab initio quantum chemical studies. The authors have developed a laser based pump-probe apparatus for the measurement of absolute PD cross sections for CH{sub 3}S and HS is summarized.

  13. Narrow band vacuum ultraviolet radiation, produced by fast conical discharge

    Science.gov (United States)

    Antsiferov, P. S.; Dorokhin, L. A.; Koshelev, K. N.

    2018-04-01

    The article presents the experimental study of discharges in a conical cavity, filled with Ar at pressure 80 Pa. The electrical current driver (inductive storage with plasma erosion opening switch) supplies to the load electrical current pulse with growth rate about 1012 A s‑1 and maximal value 30–40 kA. The convergent conical shock wave starts from the inner surface of the discharge cavity and collapses in ‘zippering’ mode. The pin hole camera imaging with MCP detector (time resolution 5 ns) have demonstrated the appearance of effectively fast moving compact plasma with visible velocity v  =  (1.5  ±  0.14)  ×  107 cm s‑1. Plasma emits narrow band radiation in the spectral range of Rydberg series transitions of Ar VII, Ar VIII with quantum number up to n  =  9 (wavelength about 11 nm). The intensity of radiation is comparable with the total plasma emission in the range 10–50 nm. Charge exchange between multiply charged Ar ions and cold Ar atoms of working gas is proposed as the possible mechanism of the origin of the radiation.

  14. State-to-state vacuum ultraviolet photodissociation study of CO2 on the formation of state-correlated CO(X(1)Σ(+); v) with O((1)D) and O((1)S) photoproducts at 11.95-12.22 eV.

    Science.gov (United States)

    Lu, Zhou; Chang, Yih Chung; Benitez, Yanice; Luo, Zhihong; Houria, Adel Ben; Ayari, Tarek; Al Mogren, Muneerah Mogren; Hochlaf, M; Jackson, W M; Ng, C Y

    2015-05-07

    The state-to-state photodissociation of CO2 is investigated in the VUV range of 11.94-12.20 eV by using two independently tunable vacuum ultraviolet (VUV) lasers and the time-sliced velocity-map-imaging-photoion (VMI-PI) method. The spin-allowed CO(X(1)Σ(+); v = 0-18) + O((1)D) and CO(X(1)Σ(+); v = 0-9) + O((1)S) photoproduct channels are directly observed from the measurement of time-sliced VMI-PI images of O((1)D) and O((1)S). The total kinetic energy release (TKER) spectra obtained based on these VMI-PI images shows that the observed energetic thresholds for both the O((1)D) and O((1)S) channels are consistent with the thermochemical thresholds. Furthermore, the nascent vibrational distributions of CO(X(1)Σ(+); v) photoproducts formed in correlation with O((1)D) differ significantly from that produced in correlation with O((1)S), indicating that the dissociation pathways for the O((1)D) and O((1)S) channels are distinctly different. For the O((1)S) channel, CO(X(1)Σ(+); v) photoproducts are formed mostly in low vibrational states (v = 0-2), whereas for the O((1)D) channel, CO(X(1)Σ(+); v) photoproducts are found to have significant populations in high vibrationally excited states (v = 10-16). The anisotropy β parameters for the O((1)D) + CO(X(1)Σ(+); v = 0-18) and O((1)S) + CO(X(1)Σ(+); v = 0-9) channels have also been determined from the VMI-PI measurements, indicating that CO2 dissociation to form the O((1)D) and O((1)S) channels is faster than the rotational periods of the VUV excited CO2 molecules. We have also calculated the excited singlet potential energy surfaces (PESs) of CO2, which are directly accessible by VUV excitation, at the ab initio quantum multi-reference configuration interaction level of theory. These calculated PESs suggest that the formation of CO(X(1)Σ(+)) + O((1)S) photoproducts occurs nearly exclusively on the 4(1)A' PES, which is generally repulsive with minor potential energy ripples along the OC-O stretching coordinate. The

  15. An analysis of oblique angle stimulated cherenkov radiation with some experimental results

    International Nuclear Information System (INIS)

    Piestrup, M.A.

    1983-01-01

    This paper considers the possible amplification in a dielectric medium of a plane wave intersected by an electron beam at the Cherenkov angle. An oscillator is designed in which a Fabry-Perot resonator's axis is placed at this angle. The gain is found to be inversely proportional to the wavelength, suggesting the possibility of a vacuum ultraviolet or soft X-ray laser. The randomization of the phase coherence between the wave and the electrons due to multiple scattering of the electrons by the atoms of the dielectric is minimized by limiting the length of interaction, and increasing the electron beam energy. Early unpublished experiments are given in which quartz resonators were placed in the Mark III Linear Accelerator's electron beam at Stanford University. From this, other subsequent experimental work, and the theory derived here, two devices are considered which utilize gas as a dielectric instead of a solid

  16. Semiconductor optical amplifier based swept wavelength source at 1060 nm using a scanning Fabry-Perot filter and an YDFA-based booster amplifier

    DEFF Research Database (Denmark)

    Nielsen, Frederik Donbæk; Thrane, Lars; Hsu, Kevin

    2007-01-01

    We demonstrate a tuneable laser operating in the 1–1.1 lm wavelength region with a tuning range of 43 nm (FWHM), an output power of 19 mW and coherence length of 14 mm. The source is based on a master laser consisting of a cavity tuned ring configuration with a fibre Fabry–Perot filter used...

  17. Dynamic characteristics of undoped and p-doped Fabry-Perot InAs/InP quantum dash based ridge waveguide lasers for access/metro networks

    International Nuclear Information System (INIS)

    Mollet, O.; Martinez, A.; Merghem, K.; Ramdane, A.; Joshi, S.; Provost, J.-G.; Lelarge, F.

    2014-01-01

    In this paper, we report the characteristics of InAs/InP quantum dashes (QDash) based lasers emitting around 1.55 μm. An unprecedented high modal gain of ∼100 cm −1 is obtained for an optimized active structure by stacking 12 QDash layers. Directly modulated lasers allowed achieving a modulation bandwidth of ∼10 GHz and a Henry factor around 5. Thanks to p-type doping, the Henry factor value is reduced down to 2.7 while the modulation bandwidth still amounts to ∼10 GHz. This shows that doping of the active region is important to improve the dynamic characteristics of QDash lasers.

  18. Fabry-Perot Interferometer and Skymapping Photometer Determinations of Midlatitude F-Region Neutral Winds and Temperatures and Airglow Enhancement/Depletions.

    Science.gov (United States)

    1984-10-26

    or Sonda rockets by use of a sky-mapping filter photometer. To this end a modified Airstream trailer containing a 100 mm aperture photoelectric Fabry...Results A. Airglow Enhancements/Depletions As a result of the failure of the Sonda rockets to reach their intended release altitudes, the only

  19. Light Transmission and Surface-Enhanced Raman Scattering of Quasi-3D Plasmonic Nanostructure Arrays with Deep and Shallow Fabry-Perot Nanocavities

    Czech Academy of Sciences Publication Activity Database

    Xu, J.; Guan, P.; Kvasnička, Pavel; Gong, H.; Homola, Jiří; Yu, Q.

    2011-01-01

    Roč. 115, č. 22 (2011), s. 10996-11002 ISSN 1932-7447 R&D Projects: GA AV ČR KAN200670701 Institutional research plan: CEZ:AV0Z20670512 Keywords : localized surface plasmon * surface enhanced raman scattering * finite differences-time domain Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering Impact factor: 4.805, year: 2011

  20. Two-dimensional distribution of electron temperature in ergodic layer of LHD measured from line intensity ratio of CIV and NeVIII

    International Nuclear Information System (INIS)

    Wang, Erhui; Morita, Shigeru; Goto, Motoshi; Murakami, Izumi; Oishi, Tetsutarou; Dong, Chunfeng

    2013-01-01

    Two-dimensional distribution of impurity lines emitted from ergodic layer with stochastic magnetic field lines in Large Helical Device (LHD) has been observed using a space-resolved extreme ultraviolet (EUV) spectrometer. The two-dimensional electron temperature distribution in the ergodic layer is successfully measured using the line intensity ratio of Li-like NeVIII 2s-3p ( 2 S 1/2 - 2 P 3/2 : 88.09 Å, 2 S 1/2 - 2 P 1/2 : 88.13 Å) to 2p-3s ( 2 P 1/2 - 2 S 1/2 : 102.91 Å, 2 P 3/2 - 2 S 1/2 : 103.09 Å) transitions emitted from radial location near Last Closed Flux Surface (LCFS). The intensity ratio analyzed with ADAS code shows no dependence on the electron density below 10 14 cm -3 . The result indicates a little higher temperature, i.e., 220 eV, in the poloidal location at high-field side near helical coils called O-point compared to the temperature near X-point, i.e., 170 eV. The electron temperature profile is also measured at the edge boundary of ergodic layer using the line intensity ratio of Li-like CIV 2p-3d ( 2 P 1/2 - 2 D 3/2 : 384.03 Å, 2 P 3/2 - 2 D 5/2 : 384.18 Å) to 2p-3s ( 2 P 1/2 - 2 S 1/2 : 419.53 Å, 2 P 3/2 - 2 S 1/2 : 419.71 Å) transitions. The intensity ratios analyzed with CHIANTI, ADAS and T.Kawachi codes show a slightly higher temperature near O-point, i.e., 25 eV for CHIANTI, 21 eV for ADAS and 11 eV for T.Kawachi's codes, compared to the temperature at X-point, i.e., 15 - 21 eV for CHIANTI, 9 - 15 eV for ADAS and 6 - 9 eV for T.Kawachi codes. It suggests that the transport coefficient in the ergodic layer is varied with three-dimensional structure. (author)

  1. Vacuum ultraviolet photoabsorption of prime ice analogues of Pluto and Charon

    Science.gov (United States)

    Pavithraa, S.; Lo, J.-I.; Rahul, K.; Raja Sekhar, B. N.; Cheng, B.-M.; Mason, N. J.; Sivaraman, B.

    2018-02-01

    Here we present the first Vacuum UltraViolet (VUV) photoabsorption spectra of ice analogues of Pluto and Charon ice mixtures. For Pluto the ice analogue is an icy mixture containing nitrogen (N2), carbon monoxide (CO), methane (CH4) and water (H2O) prepared with a 100:1:1:3 ratio, respectively. Photoabsorption of icy mixtures with and without H2O were recorded and no significant changes in the spectra due to presence of H2O were observed. For Charon a VUV photoabsorption spectra of an ice analogue containing ammonia (NH3) and H2O prepared with a 1:1 ratio was recorded, a spectrum of ammonium hydroxide (NH4OH) was also recorded. These spectra may help to interpret the P-Alice data from New Horizons.

  2. VACUUM ULTRAVIOLET PHOTOABSORPTION SPECTRA OF NITRILE ICES FOR THEIR IDENTIFICATION ON PLUTO

    Energy Technology Data Exchange (ETDEWEB)

    Sivaraman, B.; Pavithraa, S. [Atomic Molecular and Optical Physics Division, Physical Research Laboratory, Ahmedabad, 380 009 (India); Lo, J.-I.; Cheng, B.-M. [National Synchrotron Radiation Research Center, Hsinchu 30076, Taiwan (China); Sekhar, B. N. Raja [Atomic and Molecular Physics Division, BARC at RRCAT, Indore, 452 013 (India); Hill, H. [International Space University, F-67400 Illkirch (France); Mason, N. J., E-mail: bhala@prl.res.in [Department of Physical Sciences, The Open University, Milton Keynes, MK7 6AA (United Kingdom)

    2016-07-10

    Icy bodies, such as Pluto, are known to harbor simple and complex molecules. The recent New Horizons flyby of Pluto has revealed a complex surface composed of bright and dark ice surfaces, indicating a rich chemistry based on nitrogen (N{sub 2}), methane (CH{sub 4}), and carbon monoxide (CO). Nitrile (CN) containing molecules such as acetonitrile (CH{sub 3}CN), propionitrile (CH{sub 3}CH{sub 2}CN), butyronitrile (CH{sub 3}CH{sub 2}CH{sub 2}CN), and isobutyronitrile ((CH{sub 3}){sub 2}CHCN) are some of the nitrile molecules that are known to be synthesized by radiative processing of such simple ices. Through the provision of a spectral atlas for such compounds we propose that such nitriles may be identified from the ALICE payload on board New Horizons .

  3. Production and analysis of some atomic emission spectra in the vacuum ultraviolet

    International Nuclear Information System (INIS)

    Meijer, F.G.

    1979-01-01

    The development of technical facilities for spectra analysis are described including the design, construction and adjustment of a grazing incidence spectrograph for the extreme ultraviolet and the improvements in light sources. The investigations of the fifth and fourth spectra of tantalum, the analysis of the sixth spectrum of tungsten, the extension of the analysis of the fourth spectrum of hafnium and a start of the analysis of the seventh spectrum of rhenium are presented. (C.F.)

  4. Characterization of Vacuum Ultraviolet (VUV) Radiation for the Development of a Fluorescent Lamp

    International Nuclear Information System (INIS)

    Khatun, Hasina; Sharma, A. K.; Barhai, P. K.

    2011-01-01

    A negative unipolar pulsed voltage is applied to study internal electrical parameters of the xenon filled dielectric barrier discharge (DBD) sources. The VUV radiation emitted from these sources is characterized by means of the photoluminescence intensity of the red phosphor pellet. The red phosphor converts the VUV radiation into visible radiation and the emission spectra include a peak at 619.56 nm. The emission characteristics of the red phosphor are analyzed in terms of the pressure-distance (pd), rise time and frequency of the pulsed voltage waveform. The emission intensity measured at different operational conditions confirms that the formation and decay of the xenon excimer, Xe 2 *, increase with the increase in reduced electric field, E/N. After exceeding certain limits of E/N, the intensity of Xe 2 * decreases rapidly. (plasma technology)

  5. Total reflection amorphous carbon mirrors for vacuum ultraviolet free electron lasers

    Czech Academy of Sciences Publication Activity Database

    Steeg, B.; Juha, Libor; Feldhaus, J.; Jacobi, S.; Sobierajski, R.; Michaelsen, C.; Andrejczuk, A.; Krzywinski, J.

    2004-01-01

    Roč. 84, č. 5 (2004), s. 657-659 ISSN 0003-6951 R&D Projects: GA MŠk LN00A100 Institutional research plan: CEZ:AV0Z1010921 Keywords : free-electron laser * amorphous carbon * radiation damage Subject RIV: BH - Optics, Masers, Lasers Impact factor: 4.308, year: 2004

  6. Resolution of isomeric new designer stimulants using gas chromatography - Vacuum ultraviolet spectroscopy and theoretical computations

    Czech Academy of Sciences Publication Activity Database

    Škultéty, L'udovít; Fryčák, P.; Qiu, CL.; Smuts, J.; Shear-Laude, L.; Lemr, Karel; Mao, J.X.; Kroll, P.; Schug, K. A.; Szewczak, A.; Vaught, C.; Lurie, I.; Havlíček, Vladimír

    2017-01-01

    Roč. 971, JUNE 8 (2017), s. 55-67 ISSN 0003-2670 R&D Projects: GA MŠk(CZ) LO1509 Institutional support: RVO:61388971 Keywords : Gas phase absorption * Time-dependent density functional theory * Isomeric drugs Subject RIV: CB - Analytical Chemistry, Separation OBOR OECD: Analytical chemistry Impact factor: 4.950, year: 2016

  7. Absorptiemetingen aan dunne goud- en zilverlagen in het vacuum-ultraviolet

    NARCIS (Netherlands)

    Simons, Cornelis Frans Ernst

    1942-01-01

    The present thesis deals with the absorption of solid gold and silver in the far-ultraviolet between 1000 en 1800 A. From the absorptioncoefficients in this region we can draw some conclusions as to the energy-levels of the two elements in the solid state. In addition to a short survey of the

  8. Vacuum-ultraviolet (VUV) photoionization of small methanol and methanol-water clusters

    Energy Technology Data Exchange (ETDEWEB)

    Ahmed, Musahid; Ahmed, Musahid; Wilson, Kevin R.; Belau, Leonid; Kostko, Oleg

    2008-05-12

    In this work we report on thevacuum-ultraviolet (VUV) photoionization of small methanol and methanol-water clusters. Clusters of methanol with water are generated via co-expansion of the gas phase constituents in a continuous supersonic jet expansion of methanol and water seeded in Ar. The resulting clusters are investigated by single photon ionization with tunable vacuumultraviolet synchrotron radiation and mass analyzed using reflectron mass spectrometry. Protonated methanol clusters of the form (CH3OH)nH + (n=1-12) dominate the mass spectrum below the ionization energy of the methanol monomer. With an increase in water concentration, small amounts of mixed clusters of the form (CH3OH)n(H2O)H + (n=2-11) are detected. The only unprotonated species observed in this work are the methanol monomer and dimer. Appearance energies are obtained from the photoionization efficiency (PIE) curves for CH3OH +, (CH 3OH)2 +, (CH3OH)nH + (n=1-9), and (CH 3OH)n(H2O)H + (n=2-9 ) as a function of photon energy. With an increase in the water content in the molecular beam, there is an enhancement of photoionization intensity for methanol dimer and protonated methanol monomer at threshold. These results are compared and contrasted to previous experimental observations.

  9. [Study on the vacuum ultraviolet transmittance of barium fluoride crystals at different temperature].

    Science.gov (United States)

    Peng, Ru-Yi; Fu, Li-Ping; Tao, Ye

    2014-03-01

    Two VUV-grade BaF2 windows with 0.5 mm-thick and 1 mm-thick respectively were selected to study the transmittance variety with the temperature. The results show that the cutoff wavelength of BaF2 crystals will shift towards the long wave with the increase in temperature. In a certain temperature range, BaF2 crystals can depress 130.4 nm radiation well, and also has a high transmittance at 135.6 nm. Compared with the reported method in which SrF2 crystals can be applied to suppress 130.4 nm stray light by heating, BaF2 crystal can inhibit the 130. 4 nm emission line completely, and thus reduce the power consumption of the device at the same time. This indicates that BaF2 crystals can play an important role in the ionosphere optical remote sensing detection.

  10. Internal energy selection in vacuum ultraviolet photoionization of ethanol and ethanol dimers

    Science.gov (United States)

    Bodi, Andras

    2013-10-01

    Internal energy selected ethanol monomer and ethanol dimer ions were prepared by threshold photoionization of a supersonic molecular beam seeded with ethanol. The dissociative photoionization processes of the monomer, the lowest-energy CH3-loss channel of the dimer, and the fragmentation of larger clusters were found to be disjunct from the ionization onset to about 12 eV, which made it possible to determine the 0 K appearance energy of C-C bond breaking in the H-donor unit of the ethanol dimer cation as 9.719 ± 0.004 eV. This reaction energy is used together with ab initio calculations in a thermochemical cycle to determine the binding energy change from the neutral ethanol dimer to a protonated ethanol-formaldehyde adduct. The cycle also shows general agreement between experiment, theory, and previously published enthalpies of formation. The role of the initial ionization site, or rather the initial photoion state, is also discussed based on the dimer breakdown diagram and excited state calculations. There is no evidence for isolated state behavior, and the ethanol dimer dissociative photoionization processes appear to be governed by statistical theory and the ground electronic state of the ion. In the monomer breakdown diagram, the smoothly changing branching ratio between H and CH3 loss is at odds with rate theory predictions, and shows that none of the currently employed few-parameter rate models, appropriate for experimental rate curve fitting, yields a correct description for this process in the experimental energy range.

  11. Vacuum-ultraviolet electronic properties of liquids. Annual progress report, November 1, 1980-January 31, 1982

    International Nuclear Information System (INIS)

    Painter, L.R.

    1980-01-01

    Progress is reviewed on the following research areas: (1) electron mean free paths in liquid formamide; (2) yields and mean free paths of photoelectrons from liquid hexamethylphosphorictricamide; (3) evidence for collective electronic oscillations in electron bombarded liquid siloxane; (4) a new technique for measuring the reflectance of high vapor pressure liquids; (5) construction of soft x-ray monochromator; (6) electronic properties of benzene and methyl benzene derivatives; (7) optical and dielectric functions of squalane and squalene; and (8) photoemission of squalene and tetraglyme. Separate abstracts were prepared for the two papers included, and are entered in the data base separately

  12. Vacuum ultraviolet photolysis of acetylene in the 110- to 135-nm region

    International Nuclear Information System (INIS)

    Tiee, J.J.; Sander, R.K.; Quick, C.R.; Estler, R.

    1986-01-01

    State-specific photofragmentation of acetylene in the 110- to 135-nm region has been studied using vuv laser and synchrotron sources. Investigations have been focused on learning the spectroscopic identity of the excited photoproducts by examining their time-resolved fluorescence. Results of the quenching of the excited photofragment emission and the emission polarization measurements are presented. An interpretation of these results in relating the observed photoproducts to the vuv photodissociation process is discussed. 13 refs., 3 figs., 1 tab

  13. Climatologies of nighttime upper thermospheric winds measured by ground-based Fabry-Perot interferometers during geomagnetically quiet conditions: 2. High-latitude circulation and interplanetary magnetic field dependence

    DEFF Research Database (Denmark)

    Emmert, J.T.; Hernandez, G.; Jarvis, M.J.

    2006-01-01

    We analyze upper thermospheric (similar to 250 km) nighttime horizontal neutral wind patterns, during geomagnetically quiet (Kp <3) conditions, over the following locations: South Pole (90 degrees S), Halley (76 degrees S, 27 degrees W), Millstone Hill (43 degrees N, 72 degrees W), Sondre Stromfj...

  14. Surface-micromachined Bragg Reflectors Based on Multiple Airgap/SiO2 Layers for CMOS-compatible Fabry-perot Filters in the UV-visible Spectral Range

    NARCIS (Netherlands)

    Ghaderi, M.; Ayerden, N.P.; De Graaf, G.; Wolffenbuttel, R.F.

    2014-01-01

    In CMOS-compatible optical filter designs, SiO2 is often used as the low-index material, limiting the optical contrast (nHi/nLo) to about 2. Using the air as low-index material improves the optical contrast by about 50%, thus increasing the reflectivity and bandwidth at a given design complexity.

  15. Lightweight Tunable Infrared Filter, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — Michigan Aerospace Corporation has developed spaceflight qualified compact tunable Fabry-Perot interferometers for a number of applications, from ranging direct...

  16. On open electromagnetic resonators: relation between interferometers and resonators

    International Nuclear Information System (INIS)

    Manenkov, Aleksandr A; Bykov, Vladimir P; Kuleshov, N V

    2010-01-01

    The physical difference between the concepts 'Fabry-Perot interferometer' and 'open resonator' is discussed. It is shown that the use of the term 'Fabry-Perot resonator' for open laser resonators is incorrect both from the historical viewpoint and from the viewpoint of the physical meaning of the processes occurring in these resonators. (laser beams and resonators)

  17. High repetition rate Q-switched Er3+-doped fiber ring laser

    DEFF Research Database (Denmark)

    Sejka, Milan; Poulsen, Christian; Shi, Yuan

    1993-01-01

    In this paper we present for the first time Q switched Er-doped fibre laser utilising a ring Fabry-Perot cavity......In this paper we present for the first time Q switched Er-doped fibre laser utilising a ring Fabry-Perot cavity...

  18. The Study of State-Selected Ion-Molecule Reactions using the Vacuum Ultraviolet Pulsed Field Ionization-Photoion Technique

    Science.gov (United States)

    2006-01-01

    compete with the more efficient pro- enological cross sections by Chupka et al.,, and unpub- ton transfer and charge-transfer channels. The survival of...Palmieri surface. At enological cross sections derived by Chupka and et al.22-4 It 0.6 eV, Tang et al. succeeded in measuring cross sections is seen in Fig

  19. Recent advances in incoherent light sources in the vacuum-ultraviolet (88-200nm) based on electric discharge plasmas

    International Nuclear Information System (INIS)

    Ward, B.K.; Carman, R.J.; Mildren, R.P.; Kane, D.M.

    2004-01-01

    Full text: Rare-gas and rare gas-halide excimer lamps are powerful, frequency agile, mercury-free sources of high power, narrow band (10nm-30nm), UV and VUV radiation covering the wavelength range 88nm-320nm. A very efficient and practically convenient method of excitation is achieved using the dielectric barrier discharge (DBD). In the DBD, charge build-up on an insulating (dielectric) barrier at one or both of the electrodes provides an intrinsic mechanism for quenching the discharge before the transition to a high current discharge. The UV/VUV output from rare-gas DBD lamps is highly monochromatic, derived predominantly from 2nd excimer continuum, with negligible output at visible and infrared wavelengths. For DBD lamps powered by sinusoidal voltage waveforms (50Hz-100kHz), the electrical to optical conversion efficiency typically reaches 10-20%. The discharge structure consists of multiple transient plasma aments that occur stochastically in time during the discharge cycle leading to VUV output pulses with irregular spacing and amplitude. We have shown, however, that using discrete high-voltage pulses of relatively short duration, produces a short-lived homogeneous discharge that generates much higher peak power from short (sub-microsecond) VUV output pulses, with an additional increase (two- fold) in overall efficiency. Conversion efficiencies between 40-60% have also been reported for short-pulse excitation techniques. Efficient generation of pulsed, high peak-power VUV output is of interest for a broad range of applications in time-resolved spectroscopy, photo-lithography, materials processing and surface modification/cleaning, killing of micro- organisms and bacteria, sterilization, and in ozone production for water purification

  20. Investigation of the vacuum ultraviolet fluorescence of gaseous xenon under optical excitation in an extended wavelength region

    International Nuclear Information System (INIS)

    Brodmann, R.; Zimmerer, G.; Hamburg Univ.; Hahn, U.

    1976-02-01

    The fluorescence of Xe at a pressure of 10 Torr has been excited by monochromatic light in the wavelength region from 1,040 A to 1,500 A. Besides the well known first and second continuum additional emission bands appear at 1,192 A and 1,300 A. They are ascribed to an atomic transition 5d(3/2) 1 → 1 S 0 and a molecular transition O + sub(u)(6s'(1/2) + 1 S 0 ) → O + sub(g)( 1 S 0 + 1 S 0 ). The excitation spectra of the first and second continuum yield high fluorescence efficiency if higher Rydberg states are excited. Excitation of the first resonance line of Xe results in a low fluorescence intensity. Obviously the formation of highly excited molecules Xe** and intramolecular relaxation play an important role for the population of the vibrationally relaxed excited states (O + sub(u), 1sub(u)) of the Xe* 2 molecule. (orig.) [de

  1. Development of High-Reflectivity Optical Coatings for the Vacuum Ultraviolet and Verification on a Sounding Rocket Flight

    Data.gov (United States)

    National Aeronautics and Space Administration — We desire to develop new thin film coatings of fluorides to utilize the high intrinsic reflectivity of aluminum. Highly controllable thickness of fluorides can be...

  2. International Conference on Vacuum Ultraviolet Radiation Physics, 8th, Lunds Universitet, Sweden, Aug. 4-8, 1986, Proceedings

    Science.gov (United States)

    Nilsson, Per-Olof (Editor); Nordgren, Joseph (Editor)

    1987-01-01

    The interactions of VUV radiation with solids are explored in reviews and reports of recent theoretical and experimental investigations from the fields of atomic and molecular physics, solid-state physics, and VUV instrumentation. Topics examined include photoabsorption and photoionization, multiphoton processes, plasma physics, VUV lasers, time-resolved spectroscopy, synchrotron radiation centers, solid-state spectroscopy, and dynamical processes involving localized levels. Consideration is given to the fundamental principles of photoemission, spin-polarized photoemission, inverse photoemission, semiconductors, organic materials, and adsorbates.

  3. The Normal-incidence Vacuum-ultraviolet Spectrometer for the TJ-II and First Experimental Results

    International Nuclear Information System (INIS)

    McCarthy, K. J.; Zurro, B.; Baciero, A.

    2002-01-01

    A normal-incidence spectrometer, operating in the extreme-ultraviolet and ultraviolet wavelength regions, has been commissioned for the TJ-II stellarator. The instrument has been custom built by McPherson, Chelmsford, MA, and has several unique features and accessories that are described here. The instrument and CCD detector has been tested and calibrated, and its performance evaluated, using spectral lines from glow discharges and a RF excited flow lamp. Finally, the first spectra collected with the instrument of TJ-II plasmas are presented and a preliminary estimation of an oxygen ion temperature is made. (Author) 23 refs

  4. The Normal-incidence Vacuum-ultraviolet Spectrometer for the TJ-II and First Experimental Results

    Energy Technology Data Exchange (ETDEWEB)

    McCarthy, K.J.; Zurro, B.; Baciero, A.

    2002-07-01

    A normal-incidence spectrometer, operating in the extreme-ultraviolet and ultraviolet wavelength regions, has been commissioned for the TJ-II stellarator. The instrument has been custom built by McPherson, Chelmsford, MA, and has several unique features and accessories that are described here. The instrument and CCD detector has been tested and calibrated, and its performance evaluated, using spectral lines from glow discharges and a RF excited flow lamp. Finally, the first spectra collected with the instrument of TJ-II plasmas are presented and a preliminary estimation of an oxygen ion temperature is made. (Author) 23 refs.

  5. Vacuum-ultraviolet ellipsometry spectra and optical properties of Ba(Zr,Ti)O.sub.3./sub. films

    Czech Academy of Sciences Publication Activity Database

    Suchaneck, G.; Chernova, Ekaterina; Kleiner, A.; Liebschner, R.; Jastrabík, Lubomír; Meyer, D.C.; Dejneka, Alexandr; Gerlach, G.

    2017-01-01

    Roč. 621, Jan (2017), s. 58-62 ISSN 0040-6090 R&D Projects: GA ČR GA15-13778S Institutional support: RVO:68378271 Keywords : barium zirconate titanate thin film * film structure * VUV ellipsometry * optical properties Subject RIV: BM - Solid Matter Physics ; Magnetism OBOR OECD: Condensed matter physics (including formerly solid state physics, supercond.) Impact factor: 1.879, year: 2016

  6. Online study on the co-pyrolysis of coal and corn with vacuum ultraviolet photoionization mass spectrometry.

    Science.gov (United States)

    Weng, Jun-Jie; Liu, Yue-Xi; Zhu, Ya-Nan; Pan, Yang; Tian, Zhen-Yu

    2017-11-01

    With the aim to support the experimental tests in a circulating fluidized bed pilot plant, the pyrolysis processes of coal, corn, and coal-corn blend have been studied with an online pyrolysis photoionization time-of-flight mass spectrometry (Py-PI-TOFMS). The mass spectra at different temperatures (300-800°C) as well as time-evolved profiles of selected species were measured. The pyrolysis products such as alkanes, alkenes, phenols, aromatics, as well as nitrogen- and sulfur-containing species were detected. As temperature rises, the relative ion intensities of high molecular weight products tend to decrease, while those of aromatics increase significantly. During the co-pyrolysis, coal can promote the reaction temperature of cellulose in corn. Time-evolved profiles demonstrate that coal can affect pyrolysis rate of cellulose, hemicellulose, and lignin of corn in blend. This work shows that Py-PI-TOFMS is a powerful approach to permit a better understanding of the mechanisms underlying the co-pyrolysis of coal and biomass. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. Metamaterial Perfect Absorber Analyzed by a Meta Cavity Model Consisting of Multilayer Metasurfaces (Postprint)

    Science.gov (United States)

    2017-09-05

    The phase condition in Eq. 3 suggests a Fabry-Perot cavity-like mechanism. The cross-wire acts as a “mirror” that reflects light due to its high...is achieved by the Fabry-Perot cavity resonance via multiple reflections between the “quasi-open” boundary of resonator and the “close” boundary of...achieved by the Fabry- Perot cavity resonance via multiple reflections between the “quasi-open” boundary of resonator and the “close” boundary of

  8. A Cascadable, Monolithic Laser/Modulator/Amplifier Transmitter

    National Research Council Canada - National Science Library

    Forrest, Stephen

    1997-01-01

    .... These included low threshold, strained InGaAsP multiple quantum well (MQW) Fabry Perot lasers which exhibited the lowest threshold current densities ever achieved for GSMBE grown material operating at 1.3 um...

  9. Linearly Polarized Dual-Wavelength Vertical-External-Cavity Surface-Emitting Laser (Postprint)

    National Research Council Canada - National Science Library

    Fan, Li; Fallahi, Mahmoud; Hader, Joerg; Zakharian, Aramais R; Moloney, Jerome V; Stolz, Wolfgang; Koch, Stephan W; Bedford, Robert; Murray, James T

    2007-01-01

    The authors demonstrate the multiwatt linearly polarized dual-wavelength operation in an optically pumped vertical-external-cavity surface-emitting laser by means of an intracavity tilted Fabry-Perot...

  10. 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.)

  11. On a choice of an optimum scheme and parameters of laser-interferometric gravitational wave antenna

    International Nuclear Information System (INIS)

    Alekseev, A.D.; Kolosnitsyn, N.I.

    1985-01-01

    Efficiency of laser-interferometric gravitational wave antenna was analysed. Frequency characteristics of antenna with optical delay lines and the Fabry-Perot resonators are given. Sensitivity of antenna with the Fabry-Perot resonator near zero is considerably higher than sensitivity of antenna with delay lines (approximately 300 times). However this difference diminishes quickly with frequency growth. Beginning approximately from a frequency ν=200 Hz antenna sensitivity with delay lines turns out to be higher as compared with antenna with the Fabry-Perot resonator. In the frequency range of about 1.5 kHz sensitivity of antenna with delay line is about two times higher in comparison with antenna with the Fabry-Perot resonator

  12. Compact Tunable High-Efficiency Entangled Photon Source, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — MagiQ proposes to develop a compact tunable high-efficiency low-power-consumption entangled photon source. The source, based on inter-Fabry-Perot-cavity Spontaneous...

  13. 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...

  14. Nonlinear Optics and Nonlinear Dynamics in Semiconductor Lasers Subject to External Optical Injection

    National Research Council Canada - National Science Library

    Simpson, Thomas

    2000-01-01

    ...) arrays, and analysis of chaotic dynamics that can be induced by optical injection. Under external optical injection, all semiconductor lasers tested, conventional edge emitting Fabry Perot laser diodes, VCSELs, and distributed feedback (DFB...

  15. Advanced Optical Diagnostics for HF Laser Development

    National Research Council Canada - National Science Library

    Rawlins, W

    2002-01-01

    .... The instrument is based on hyperspectral imaging using a low order Fabry-Perot interferometer. The basic theory behind this technology is described and several applications to a chemically reacting flow field are presented...

  16. Gain and Loss in an Optically Pumped Mid-Infrared Laser

    National Research Council Canada - National Science Library

    Ongstad, A. P; Kaspi, R; Moeller, C. M; Tilton, M. L; Chavez, J. R

    2003-01-01

    ...) spectrometer was used to measure the laser mode spectra below threshold. To obtain an accurate determination of the gain, a full curve fit to the spectral output of the Fabry-Perot cavity was utilized...

  17. Finite-Difference Time-Domain Integration of Ultrafast Dynamics in Optical Resonators

    National Research Council Canada - National Science Library

    Basinger, Scott

    1993-01-01

    .... The resonator is a Fabry-Perot cavity that has a nonlinear absorbing material in the center. When an optical field of the resonant frequency is incident upon the cavity, the field intensity increases inside the cavity...

  18. ISS SpaceCube Experiment – Mini

    Data.gov (United States)

    National Aeronautics and Space Administration — Development of flight software for the Fabry-Perot Spectrometer (FPS) and the integration of the Autonomous On-board Processing for Sensor Systems (AOPSS) technology...

  19. 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.

  20. 355nm Photon-Recycled Fringe Imager for HSRL Project

    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...

  1. Fiber-optic pressure sensors for internal combustion engines.

    Science.gov (United States)

    Atkins, R A; Gardner, J H; Gibler, W N; Lee, C E; Oakland, M D; Spears, M O; Swenson, V P; Taylor, H F; McCoy, J J; Beshouri, G

    1994-03-01

    Two designs incorporating embedded fiber Fabry-Perot interferometers as strain gauges were used for monitoring gas pressure in internal combustion engines. Measurements on a Diesel engine, a gasoline-fueled engine, and a natural-gas engine are reported.

  2. 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...

  3. Advanced Electroactive Single Crystal and Polymer Actuators for Passive Optics, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — Large stroke and high precision electroactive single crystal and polymer actuators are desired for cryogenic passive optics such as Fabry-Perot Interferometer (FPI)...

  4. 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....

  5. 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

  6. 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

  7. Rayleigh-Brillouin scattering to determine one-dimensional temperature and number density profiles of a gas flow field

    Science.gov (United States)

    Lock, James A.; Seasholtz, Richard G.; John, W. T.

    1992-01-01

    Rayleigh-Brillouin spectra for heated nitrogen gas were measured by imaging the output of a Fabry-Perot interferometer onto a CCD array. The spectra were compared with the theoretical 6-moment model of Rayleigh-Brillouin scattering convolved with the Fabry-Perot instrument function. Estimates of the temperature and a dimensionless parameter proportional to the number density of the gas as functions of position in the laser beam were calculated by least-squares deviation fits between theory and experiment.

  8. 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

  9. Evaluation of payload performance for a sounding rocket vacuum ultraviolet spatial heterodyne spectrometer to observe C IV lambdalambda1550 emissions from the Cygnus Loop.

    Science.gov (United States)

    Watchorn, Steven; Roesler, Fred L; Harlander, John; Jaehnig, Kurt P; Reynolds, Ronald J; Sanders, Wilton T

    2010-06-10

    The results of a project to develop a spatial heterodyne spectrometer (SHS) for a sounding rocket mission to study the Cygnus Loop, a prototypical middle-aged supernova remnant, are discussed. The goal was to obtain a radial velocity-resolved spectrum of the C IV lambdalambda1550 emission line from bright features of the Cygnus Loop, as a test for mapping the diffuse hot interstellar medium (ISM). A full Fourier-transform analysis of Cygnus Loop emission data is presented, showing lack of velocity-resolved C IV emission detection. Optics contamination is shown to be the most likely problem, and ways to eliminate this contamination for future SHS sounding rocket and satellite missions are discussed.

  10. Probing the structures of neutral boron clusters using infrared/vacuum ultraviolet two color ionization: B[sub 11], B[sub 16], and B[sub 17

    NARCIS (Netherlands)

    Romanescu, C.; Harding, D. J.; Fielicke, A.; Wang, L. S.

    2012-01-01

    The structures of neutral boron clusters, B11, B16, and B17, have been investigated using vibrational spectroscopy and ab initio calculations. Infrared absorption spectra in the wavelength range of 650 to 1550 cm−1 are obtained for the three neutral boron clusters from the enhancement of their

  11. 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.

  12. Optical electromagnetic radiation detector

    International Nuclear Information System (INIS)

    Miceli, W. J.; Ludman, J. E.

    1985-01-01

    An optical electromagnetic radiation detector having a probe for receiving nearby electromagnetic radiation. The probe includes a loop antenna connected to a pair of transparent electrodes deposited on the end surfaces of an electro-optic Fabry-Perot interferometer. When the loop antenna picks up the presence of electromagnetic radiation, a voltage will be developed across the crystal of the electro-optic Fabry-Perot interferometer thereby changing the optical length of the interferometer. A beam of light from a remote location is transmitted through an optical fiber onto the Fabry-Perot interferometer. The change in optical length of the Fabry-Perot interferometer alters the intensity of the beam of light as it is reflected from the Fabry-Perot interferometer back through the optical fiber to the remote location. A beamsplitter directs this reflected beam of light onto an intensity detector in order to provide an output indicative of the variations in intensity. The variations in intensity are directly related to the strength of the electromagnetic radiation received by the loop antenna

  13. Magnetic field sensor based on anti-resonant reflecting guidance in the magnetic gel-coated hollow core fiber.

    Science.gov (United States)

    Gao, R; Jiang, Y; Zhao, Yang

    2014-11-01

    A compact all-fiber magnetic field sensor based on the magnetic gel coated hollow core fiber (HCF) has been proposed and experimentally demonstrated. A double-layered Fabry-Perot resonator is formed by coating a magnetic gel layer on the surface of the HCF. Anti-resonant reflecting guidance of light can be achieved in the HCF, and leaky mode is induced at resonant wavelength of the double-layered Fabry-Perot resonator, which results in lossy dips in the transmission spectrum of the HCF. Due to the tunable magneto-elastic effect, the shape of the magnetic gel is deformed with the external magnetic field, which results in a change of the resonate condition for the double-layered Fabry-Perot resonator. The magnetic field can be measured by interrogating the wavelength of the lossy dip. The experimental results show that a magnetic field sensitivity of 245  pm/Oe is achieved.

  14. Development of a high power optical cavity for optomechanical QND experiment

    International Nuclear Information System (INIS)

    Mori, T; Agatsuma, K; Ballmer, S; Sakata, S; Miyakawa, O; Kawamura, S; Furusawa, A; Mio, N

    2012-01-01

    In order to observe quantum radiation pressure noise and reduce it by measuring the ponderomotively squeezed light on a table-top experiment, we are developing a laser interferometer with Fabry-Perot cavities with very small suspended mirrors. As a preliminary setup, we have constructed a Fabry-Perot cavity of finesse 1300 with a suspended mirror of 20 mg. The cavity was locked stably at low laser power for which the classical radiation pressure caused little effect on the dynamics of the small mirror. For the stable operation of this cavity with higher laser power, a technique to control the motion of the small mirror, especially its yaw motion, is necessary. We describe that the motion can be stabilized through the radiation pressure of light inside the cavity, by controlling the motion of the front mirror of a Fabry-Perot cavity properly.

  15. Pass-through Mach-Zehnder topologies for macroscopic quantum measurements

    International Nuclear Information System (INIS)

    Khalili, F. Ya.

    2011-01-01

    Several relatively small-scale experimental setups, aimed on prototyping of future laser gravitational-wave detectors and testing of new methods of quantum measurements with macroscopic mechanical objects, are under development now. In these devices, not devoted directly to the gravitational-wave detection, Mach-Zehnder interferometer with pass-through Fabry-Perot cavities in the arms can be used instead of the standard Michelson/Fabry-Perot one. The advantage of this topology is that it does not contain high-reflectivity end mirrors with multilayer coatings, which Brownian noise could constitute the major part of the noise budget of the Michelson/Fabry-Perot interferometers. We consider here two variants of this topology: the 'ordinary' position meter scheme, and a new variant of the quantum speed meter.

  16. Narrow-selection bandwith of femtosecond laser comb with application to changes in optical path distance

    Science.gov (United States)

    Šmíd, Radek; Ježek, Jan; Buchta, Zden"k.; Čížek, Martin; Lazar, Josef; Číp, Ondřej

    2010-05-01

    In this contribution we propose a scheme of Fabry-Perot interferometer measuring the absolute distance in atmosferic conditions using a femtosecond laser comb. The spacing of mirrors of the Fabry-Perot interferometer represents the length standard referenced to stable optical frequency of the femtosecond mode-locked laser. With the help of highly selective optical filter it is possible to get only a few of separate spectral components. By tuning and locking of the Fabry-Perot cavity to a selected single component it is possible to get a mechanical length standard with the uncertainty of the repetition frequency of the femtosecond laser. If the interferometer measures distance in atmospheric conditions, the absolute value of the laser wavelength fluctuates with a refractive index of air. Compairing the measurement in evacuated chamber with measurement in ambient air leads to enhanced precision in measurement of refrective index of air.

  17. Observation of carbon impurity flow in the edge stochastic magnetic field layer of Large Helical Device and its impact on the edge impurity control

    Science.gov (United States)

    Oishi, T.; Morita, S.; Dai, S. Y.; Kobayashi, M.; Kawamura, G.; Huang, X. L.; Zhang, H. M.; Liu, Y.; Goto, M.; the LHD Experiment Group

    2018-01-01

    The parallel flow of carbon impurity in a thick stochastic magnetic field layer called the ‘ergodic layer’ located at the edge plasma of the Large Helical Device (LHD) is studied by space-resolved vacuum ultraviolet (VUV) spectroscopy, using a 3 m normal incidence spectrometer. A full vertical profile of C3+ impurity flow is evaluated from the Doppler shift of the second order of CIV line emission (2  ×  1548.20 Å) at a horizontally-elongated plasma position of LHD. The carbon flow at the top and bottom edges in the ergodic layer has the same direction toward the outboard side along the major radius direction. The observed flow quantitatively agrees with the simulation results calculated with a 3D simulation code, EMC3-EIRENE. It experimentally verifies the validity of edge parallel flow driving the impurity screening.

  18. 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.......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....

  19. Twin mirrors for laser interferometric gravitational-wave detectors.

    Science.gov (United States)

    Sassolas, Benoît; Benoît, Quentin; Flaminio, Raffaele; Forest, Danièle; Franc, Janyce; Galimberti, Massimo; Lacoudre, Aline; Michel, Christophe; Montorio, Jean-Luc; Morgado, Nazario; Pinard, Laurent

    2011-05-01

    Gravitational-wave detectors such as Virgo and the laser interferometric gravitational-wave observatory (LIGO) use a long-baseline Michelson interferometer with Fabry-Perot cavities in the arms to search for gravitational waves. The symmetry between the two Fabry-Perot cavities is crucial to reduce the interferometer's sensitivity to the laser amplitude and frequency noise. To this purpose, the transmittance of the mirrors in both cavities should be as close as possible. This paper describes the realization and the characterization of the first twin large low-loss mirrors with transmissions differing by less than 0.01%.

  20. Quantitative measurement of in-plane acoustic field components using surface-mounted fiber sensors

    Science.gov (United States)

    Claus, Richard O.; Dhawan, Rajat R.; Gunther, Michael F.; Murphy, Kent A.

    1993-01-01

    Extrinsic Fabry-Perot interferometric sensors have been used to obtain calibrated, quantitative measurements of the in-plane displacement components associated with the propagation of ultrasonic elastic stress waves on the surfaces of solids. The frequency response of the sensor is determined by the internal spacing between the two reflecting fiber endface surfaces which form the Fabry-Perot cavity, a distance which is easily controlled during fabrication. With knowledge of the material properties of the solid, the out-of-plane displacement component of the wave may also be determined, giving full field data.

  1. Further Rehabilitating CIV-based Black Hole Mass Estimates in Quasars

    Science.gov (United States)

    Brotherton, Michael S.; Runnoe, Jessie C.; Shang, Zhaohui; Varju, Melinda

    2016-06-01

    Virial black hole masses are routinely estimated for high-redshift quasars using the C IV lambda 1549 emission line using single-epoch spectra that provide a gas velocity and a continuum luminosity. Such masses are very uncertain, however, especially because C IV likely possesses a non-virial component that varies with the Eddington ratio. We have previously used the 1400 feature, a blend of S i IV and O IV] emission that does not suffer the problems of C IV, to rehabilitate C IV-based mases by providing a correction term. The C IV profile itself, however, provides enough information to correct the black hole masses and remove the effects of the non-virial component. We use Mg II-based black hole masses to calibrate and test a new C IV-based black hole mass formula using only C IV and continuum measurements superior to existing formulations, as well as to test for additional dependencies on luminosity.

  2. Stochastic Processes and Random Matrices : Lecture Notes of the Les Houches Summer School : Session CIV

    CERN Document Server

    Altland, Alexander; Fyodorov, Yan V; O'Connell, Neil; Cugliandolo, Leticia F

    2017-01-01

    Many of the distinctive and useful phenomena of soft matter come from its interaction with interfaces. Examples are the peeling of a strip of adhesive tape, the coating of a surface, the curling of a fiber via capillary forces, or the collapse of a porous sponge. These interfacial phenomena are distinct from the intrinsic behavior of a soft material like a gel or a microemulsion. Yet many forms of interfacial phenomena can be understood via common principles valid for many forms of soft matter. Our goal in organizing this school was to give students a grasp of these common principles and their many ramifications and possibilities. The Les Houches Summer School comprised over fifty 90-minute lectures over four weeks. Four four-lecture courses by Howard Stone, Michael Cates, David Nelson and L. Mahadevan served as an anchor for the program. A number of shorter courses and seminars rounded out the school. This volume collects the lecture notes of the school.

  3. 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

  4. Pramana – Journal of Physics | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    We can deduce the internal magnetic field from the analysis of circular polarization of the spectral lines emitted by the plasma. The theory of the measurement and a detailed design of the Zeeman polarimeter constructed to measure the poloidal field profile in the ADITYA tokamak are presented. The Fabry-Perot which we ...

  5. Superconducting microwave resonators for physics experiments

    International Nuclear Information System (INIS)

    Klein, N.; Muller, G.; Piel, H.; Schurr, J.

    1989-01-01

    Superconducting resonators at K-Band frequencies have been developed for different applications in general physics. The authors have built niobium pillbox cavities for the One-Atom Maser experiment by which the interaction of Rydberg atoms with single microwave photons has been investigated. At 21.5 GHz and T=1.3K quality factors of up to 10/sup 11/ were obtained. Coating of the cavity with Nb/sub 3/Sn resulted in quality factors of 6x10/sup 8/ at T=4.2K and 6x10/sup 9/ at T=2K. The authors have also investigated a superconducting Fabry-Perot resonator consisting of two spherically curved niobium mirrors. The quality factor of 1.8x10/sup 7/ measured at 25 GHz and 4.2K was found to be two orders of magnitude higher than for a corresponding copper resonator. Fabry-Perot resonators can be applied for detecting small position changes of one mirror with respect to the other e.g. caused by gravitational forces. First experiments with copper Fabry-Perot mirrors suspended in a vacuum chamber provide a maximum sensitivity for a gravitational acceleration of one mirror of 4x10/sup -11/ m/s/sup 2/. These results are promising for a possible fifth force detector based on a superconducting Fabry-Perot resonator

  6. Brillouin Instability in Fiber Lasers Doped By Power | Bouras ...

    African Journals Online (AJOL)

    The effect of Brillouin back scattering is theoretically analysed by two-coupled modes laser model. We consider the Fabry-Perot fiber laser cavity. The rich and complex dynamic behaviours are observed. In particular the quasi periodic dynamic is identified and studied. Keywords: Stimulated Brillouin Scattering; high power ...

  7. Grain size evaluation of metallic specimens using laser-ultrasonics

    International Nuclear Information System (INIS)

    Lim, Chung Soo; Park, Hyung Kook; Jeon, Hyung Ha; Kim, Dal Woo; Oh, Ki Jang; Hong, Soon Taek

    2002-01-01

    The laser-ultrasonics inspection techniques for the measurement of grain size have been developed in this study. The ultrasonics are generated by pulsed Nd:YAG laser and the pulse energy is 300 mJ and wavelength is 1064 nm. Since the frequency bandwidth of laser-ultrasonics generated by pulsed laser is extremely broad, this laser-ultrasonics are suitable for analysis of frequency dependence of ultrasonic attenuation. The attenuation coefficients (α) in thick steel plates are measured by using laser-ultrasonics of 15 MHz and 30 MHz, which is probed by confocal Fabry-Perot interferometer. The results show that the attenuation coefficients are closely related with grain size and high frequency ultrasonics are more effective to measure the fine pain size. According to the experimental results of this study, we can conclude that laser-ultrasonics inspection is effective method for grain size measurement. The confocal Fabry-Perot interferometer has been developed for non-contact measurement of laser-ultrasonics. The transmittance characteristic of interferometer has been studied experimentally with CW single-mode laser system. The results show that the Fabry-Perot interferometer is a very effective tool for the measurement of ultrasonics. Using the developed Fabry-Perot interferometer, we have measured ultrasonic signals of high temperature specimen up to 1200 degrees C.

  8. Analysis of moire figures using interferometric lattices with Airy perfils

    International Nuclear Information System (INIS)

    Rabal, H.J.; Garavaglia, M.

    1979-01-01

    Using a Fabry-Perot interferometer and a spectrograph, iluminated with white light, ondulatory spectra are obtained. The componentes are not equidistance among them and the intensity distribution obeys the Airy's law. It is been made preliminar experiments to determinate if the moire figures, generated by the ondulatory spectra interaction, allows to measure displacements, rotations, etc [es

  9. 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.

  10. Gamma irradiation of Fabry–Perot interband cascade lasers

    Energy Technology Data Exchange (ETDEWEB)

    Myers, Tanya L. [Pacific Northwest National Laboratory, Richland, Washington; Cannon, Bret D. [Pacific Northwest National Laboratory, Richland, Washington; Brauer, Carolyn S. [Pacific Northwest National Laboratory, Richland, Washington; Canedy, Chadwick L. [Naval Research Laboratory, Washington, DC; Kim, Chul Soo [Naval Research Laboratory, Washington, DC; Kim, Mijin [Sotera Defense Solutions, Inc., Columbia, Maryland; Merritt, Charles D. [Naval Research Laboratory, Washington, DC; Bewley, William W. [Naval Research Laboratory, Washington, DC; Vurgaftman, Igor [Naval Research Laboratory, Washington, DC; Meyer, Jerry R. [Naval Research Laboratory, Washington, DC

    2017-09-20

    Two Fabry-Perot interband cascade lasers (ICLs) were exposed to Cobalt-60 gamma rays for a dosage of 500 krad(Si) each, which is higher than is typically encountered in space applications. The ICLs do not show any significant changes in threshold current or slope efficiency, suggesting the suitability of ICLs for use in radiation environments.

  11. 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

  12. Progress on Passive Sensor for Ultra-Precise Measurement of C02

    Science.gov (United States)

    Heaps, William S.; Kawa, S. Randolph; Georgieva, Elena; Wilson, Emily

    2003-01-01

    We will present results from a novel instrument employing a Fabry-Perot interferometer to measure column carbon dioxide with great precision. These measurements are very important for improving our understanding of the global warming phenomenon. The instrument technique can be extended to a number of other important trace gases in the atmosphere.

  13. Research and development entitled smart structures for fossil energy applications

    Science.gov (United States)

    Claus, R. O.

    1990-12-01

    Two different fiber optic sensors were considered for use in ceramic cross flow filters. The intensity-based sensor was tested with a great degree of success. Even with a computerized data acquisition system, the intensity based sensor was unable to achieve the resolution of the Fabry-Perot sensor. Another drawback of the intensity sensor is the hysteresis behavior observed over cyclic variation of temperature. It was determined that Fabry-Perot fiber optic sensors can be used to measure thermal strains in ceramic cross flow filters with accuracies of 0.1 micron/m. The single ended approach of the reflective Fabry-Perot sensors is well suited for high thermal strain measurements; the results obtained show that the output of the fiber sensor tracks the temperature changes exactly as expected and shows no noticeable time lag between the measurand and the output signal. Sapphire fibers were manufactured with silica claddings and their spectral attenuation was measured. An intensity based sensor using sapphire fibers was fabricated and its performance calibrated. The success of the Fabry-Perot sensor has proved that such fiber optic sensors are well suited for smart structures in fossil energy applications.

  14. Utilize the spectral line pair of the same ionized state ion to measure the ion temperature of tokamak plasma

    International Nuclear Information System (INIS)

    Lin Xiaodong

    2000-01-01

    Making use of a Fabry-Perot interferometer driven by a piezoelectric crystal and selecting the suitable separation of plates, the ion temperature is defined by measuring the superimposed profile of the spectral line pair of the same ionized state ions in Tokamak. The advantage of this method is to higher spectral resolution and wider spectral range select

  15. Dynamics of the Large-Scale Galactic Wind in M82

    Science.gov (United States)

    Shopbell, P. L.; Bland-Hawthorn, J.

    1995-12-01

    We present detailed spectroscopic and multiband photometric observations of the nearby galaxy M82 in order to study the high-velocity outflows observed in such galaxies as a property of the energetic starburst phenomena associated with their nuclei. The high spatial and kinematic resolution of our Fabry-Perot observations has allowed us to perform photometric analysis of \\ha, \

  16. Research and development entitled smart structures for fossil energy applications

    Energy Technology Data Exchange (ETDEWEB)

    Claus, R.O.

    1990-12-01

    Two different fiber optic sensors were considered for use in ceramic cross flow filters. The intensity-based sensor was tested with a great degree of success. Even with a computerized data acquisition system, the intensity-based sensor was unable to achieve the resolution of the Fabry-Perot sensor. Another drawback of the intensity sensor is the hysteresis behavior observed over cyclic variation of temperature. We have determined that extrinsic Fabry-Perot fiber optic sensors can be used to measure thermal strains in ceramic cross-flow filters with accuracies of 0.1 {mu}m/m. The single ended approach of the reflective Fabry-Perot sensors is well suited for high thermal strain measurements; the results obtained show that the output of the fiber sensor tracks the temperature changes exactly as expected and shows no noticeable time lag between the measurand and the output signal. Sapphire fibers were manufactured with silica claddings and their spectral attenuation was measured. An intensity based sensor using sapphire fibers was fabricated and its performance calibrated. The success of the Fabry-Perot sensor has proved that such fiber optic sensors are ideally suited for smart structures'' in fossil energy applications. 11 refs., 43 figs.

  17. 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 ...

  18. 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...

  19. La comunicación de los próximos años

    OpenAIRE

    Martín Pereda, José Antonio

    1997-01-01

    En este artículo se recogen diversas tecnologías que pueden facilitar la comunicación en un futuro, como son las fibras ópticas dopadas con tierras raras, los resonadores no lineales de Fabry-Perot o los dispositivos semiconductores basados en pozos cuánticos.

  20. 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...

  1. Crosstalk in 1.5-μm InGaAsP optical amplifiers

    DEFF Research Database (Denmark)

    Lassen, H. E.; Hansen, Peter Bukhave; Stubkjær, Kristian

    1988-01-01

    and the detuning of the channels relative to the amplifier Fabry-Perot spectrum. Calculations of worst-case crosstalk levels are included. The model is verified experimentally for amplitude-modulated signals, and crosstalk levels up to -7 dB are reported. For frequency-modulated signals, estimated crosstalk...

  2. Pramana – Journal of Physics | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    2014-02-05

    Feb 5, 2014 ... In the present paper, we applied the technique to anisotropic gain medium such as a-cut Nd:YVO4. Using the LOPUT cavity, we demonstrated nearly 2 W of single longitudinal mode laser with nearly diffraction-limited spatial profile. Linewidth measurement using a custom-made Fabry Perot interferometer ...

  3. 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

  4. A ROTATION CURVE STUDY OF THE DWARF SC-GALAXY UGC2259

    NARCIS (Netherlands)

    GONZALEZSERRANO, JI; VALENTIJN, EA

    Scanning Fabry-Perot interferometry of the dwarf galaxy UGC 2259 in the [OIII] lambda-5007 angstrom line is presented. The velocities of twenty [OIII] emission regions belonging to the galaxy were measured. From two separate data cubes, we obtained the rotation curve of the galaxy in the radial

  5. Tunable UV Filters

    Science.gov (United States)

    Bruner, Marilyn E. (Principal Investigator); Rosenberg, William A.

    1996-01-01

    This report describes an investigation intended to determine the practical short wavelength limit for Fabry-Perot etalons operating in the far ultraviolet. This portion of the investigation includes a design study of multilayer dielectric reflector coatings that would be required by such an etalon. Results of the study indicate that etalons may be made to operate at wavelengths as short as 121 nm.

  6. Methods of direct measurement of the refraction index of air using high-resolution laser interferometry

    Czech Academy of Sciences Publication Activity Database

    Číp, Ondřej; Petrů, František; Matoušek, V.; Buchta, Z.; Lazar, Josef

    2004-01-01

    Roč. 49, č. 3 (2004), s. 88-90 ISSN 0447-6441 R&D Projects: GA AV ČR IBS2065009 Keywords : laser interferometry * refraction index * Fabry-Perot interferometer Subject RIV: BH - Optics, Masers, Lasers

  7. Etalonnage absolu d'un spectrometre SISAM.

    Science.gov (United States)

    Farrenq, R; Meyer-Bourbonneux, F; Pinson, P; Meyer, C; Barchewitz, P

    1970-07-01

    A SISAM spectrometer was adjusted. It was fitted with an apparatus for measuring absolute wavelengths. This used the fringes of a Fabry-Perot with emission lines. The results indicate that the width of the apparatus function is less than 0.025 cm(-1) and that the relative accuracy of the wavelength measurements is 0.003 cm(-1).

  8. Spectrophotometry in the far infrared. Optical and Hertzian processes

    International Nuclear Information System (INIS)

    Coste, Andre

    1968-01-01

    After a general study of problems related to instrumental spectroscopy in the far infrared, this research thesis examines the theory and technique of construction of slit spectrometers. The author then studied the possibilities to increase brightness and resolution using Fabry-Perot interferometers, and the Fourier transform interferential spectrometry, and finally addressed methods used with micro-waves

  9. Noise and resolution in IO interferometric sensing

    NARCIS (Netherlands)

    Hoekstra, Hugo; Lambeck, Paul; Koster, T.M.; Uranus, H.P.

    2007-01-01

    The paper presents a general theory for sensing devices, relating noise and device parameters to resolution of modal index changes. The theory is applied to optimise the length of a few integrated optics sensing devices, being a Mac-Zehnder interferometers and two Fabry-Perot implementations. The

  10. A high-Tc superconductor bolometer for remote sensing of atmospheric OH

    NARCIS (Netherlands)

    de Nivelle, M.J.M.E.; De Nivelle, M.J.M.E.; Bruijn, M.P.; de Vries, R.; Wijnbergen, J.J.; de Korte, P.A.J.; Sanchez, Stefan; Elwenspoek, Michael Curt; Heidenblut, T.; Schwierzi, B.; Michalke, W.; Steinbeiss, E.; Frericks, M.

    The technological feasibility is being investigated of a high-Tc superconductor transition edge bolometer for far-infrared detection, which can meet the requirements of a Fabry-Perot based satellite instrument designed for remote sensing of atmospheric OH. These include a time constant τ<0.3 s, an

  11. Laser Anemometer For Turbine Research

    Science.gov (United States)

    Seasholtz, Richard G.; Goldman, Louis J.

    1988-01-01

    Three velocity components measured through one port. Laser anemometer combines conventional interference-fringe anemometer configuration with Fabry-Perot interferometer to enable simultaneous measurement of radial and transverse velocities. Transverse-velocity axis rotated, enabling measurement of both transverse-velocity components. Does not require large optical-access port for measurement of radial velocity.

  12. The Virgo 3 km interferometer for gravitational wave detection

    NARCIS (Netherlands)

    Acernese, F.; Amico, Paolo; Alshourbagy, Mohamed; Antonucci, Federica; Aoudia, S.; Astone, P.; Avino, Saverio; Baggio, L.; Ballardin, G.; Barone, F.; Barsotti, L.; Barsuglia, M.; Bauer, Th. S.; Bigotta, Stefano; Bizouard, M. A.; Boccara, Albert-Claude; Bondu, F.; Bosi, Leone; Bradaschia, C.; van den Brand, J. F. J.; Birindelli, Simona; Braccini, Stefano; Brillet, A.; Brisson, V.; Buskulic, D.; Cagnoli, G.; Calloni, E.; Campagna, Enrico; Carbognani, F.; Cavalier, F.; Cavalieri, R.; Cella, G.; Cesarini, E.; Chassande-Mottin, E.; Clapson, A-C; Cleva, F.; Coccia, E.; Corda, C.; Corsi, A.; Cottone, F.; Coulon, J. -P.; Cuoco, E.; D'Antonio, S.; Dari, A.; Dattilo, V.; Davier, M.; Del Prete, M.; Rosa, R.; Di Fiore, L.; Di Lieto, A.; Di Virgilio, A.; Dujardin, B.; Evans, M.; Fafone, V.; Ferrante, I.; Fidecaro, F.; Fiori, I.; Flaminio, R.; Fournier, J. -D.; Frasca, S.; Frasconi, F.; Gammaitoni, L.; Garufi, F.; Genin, E.; Gennai, A.; Giazotto, A.; Giordano, L.; Granata, V.; Greverie, C.; Grosjean, D.; Guidi, G.; Hamdani, S.U.; Hebri, S.; Heitmann, H.; Hello, P.; Huet, D.; Kreckelbergh, S.; La Penna, P.; Laval, M.; Leroy, N.; Letendre, N.; Lopez, B.; Lorenzini, M.; Loriette, V.; Losurdo, G.; Mackowski, J. -M.; Majorana, E.; Man, C. N.; Mantovani, M.; Marchesoni, F.; Marion, F.; Marque, J.; Martelli, F.; Masserot, A.; Menzinger, F.; Milano, L.; Minenkov, Y.; Moins, C.; Moreau, J.; Morgado, N.; Mosca, S.; Mours, B.; Neri, I.; Nocera, F.; Pagliaroli, G.; Pallottino, G. V.; Palomba, C.; Paoletti, F.; Pardi, S.; Pasqualetti, A.; Passaquieti, R.; Passuello, D.; Piergiovanni, F.; Pinard, L.; Poggiani, R.; Punturo, M.; Puppo, P.; van der Putten, S.; Rapagnani, P.; Regimbau, T.; Reita, V.; Remillieux, A.; Ricci, F.; Ricciardi, I.; Rocchi, A.; Romano, R.; Ruggi, P.; Russo, G.; Solimeno, S.; Spallicci, A.; Tarallo, M.; Terenzi, R.; Tonelli, M.; Toncelli, A.; Tournefier, E.; Travasso, F.; Tremola, C.; Vajente, G.; Verkindt, D.; Vetrano, F.; Vicere, A.; Vinet, J. -Y.; Vocca, H.; Yvert, M.

    Virgo, designed, constructed and developed by the French-Italian VIRGO collaboration located in Cascina (Pisa, Italy) and aiming to detect gravitational waves, is a ground-based power recycled Michelson interferometer, with 3 km long suspended Fabry -Perot cavities. The first Virgo scientific

  13. The evolution of HI and CIV quasar absorption line systems at 1.9 < z < 3.2

    OpenAIRE

    Kim, Tae-Sun; Partl, Adrian M.; Carswell, Robert F.; Müller, Volker

    2013-01-01

    We have investigated the distribution and evolution of ~3100 intergalactic HI absorbers with HI column densities log N(HI) = [12.75, 17.0] at 1.9 < z < 3.2, using 18 high resolution, high S/N quasar spectra obtained from the ESO VLT/UVES archive. We used two sets of Voigt profile fitting analysis, one including all the available high-order Lyman lines to obtain reliable HI column densities of saturated lines, and another using only the Ly-alpha lines. There is no significant difference betwee...

  14. The c.IVS1+1G>A mutation inthe GJB2 gene is prevalent and large ...

    Indian Academy of Sciences (India)

    2002). Significant dif- ferences in the frequency of this deletion among probands with sensorineural hearing loss have been reported in differ- ent populations. It was found to be common in Spain, France, the United Kingdom, Israel and Brazil, less frequent in the. United States, Belgium and Australia, and detected in only a.

  15. The c.IVS1+1G>A mutation inthe GJB2 gene is prevalent and large ...

    Indian Academy of Sciences (India)

    congenital or prelingual-onset moderate to profound non- syndromic sensorineural hearing loss. Sixteen probands (12 multiplex, 4 simplex) had single exon 2 GJB2 mutations, whereas 279 probands did not have any pathological GJB2 alleles. Fifteen heterozygote probands had the c.35delG and one proband had the p.

  16. Interferometric observations of planetary nebulae

    International Nuclear Information System (INIS)

    Atherton, P.D.

    1978-01-01

    Studies of the velocity field of planetary nebulae can be used to derive important information concerning their structure and dynamics. A description is given of the design, construction and operation of a servo-controlled Fabry Perot Interferometer, for the Cassegrain focus, which was built to perform these studies. New evidence is presented concerning the structure and internal motions of NGC 3242, NGC 6720 and NGC 7027. A technique is described which uses the velocity field to map variations in the electron temperature and density along the line of sight as well as across the face of the nebula. It is shown how a Fabry Perot may be used in conjunction with multi-element array detectors to facilitate this technique. Finally some extensions to the technique of capacitance micrometry are discussed which allow the operation of a single air-spaced etalon over a wide range of capacitor gaps

  17. Fiber optic hydrophone

    Science.gov (United States)

    Kuzmenko, P.J.; Davis, D.T.

    1994-05-10

    A miniature fiber optic hydrophone based on the principles of a Fabry-Perot interferometer is disclosed. 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 optical 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. 2 figures.

  18. 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.

  19. 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.

  20. Adaptive frequency comb illumination for interferometry in the case of nested two-beam cavities

    International Nuclear Information System (INIS)

    Harder, Irina; Leuchs, Gerd; Mantel, Klaus; Schwider, Johannes

    2011-01-01

    The homogeneity test of glass plates in a Fizeau interferometer is hampered by the superposition of multiple interference signals coming from the surfaces of the glass plate as well as the empty Fizeau cavity. To evaluate interferograms resulting from such nested cavities, various approaches such as the use of broadband light sources have been applied. In this paper, we propose an adaptive frequency comb interferometer to accomplish the cavity selection. An adjustable Fabry-Perot resonator is used to generate a variable frequency comb that can be matched to the length of the desired cavity. Owing to its flexibility, the number of measurements needed for the homogeneity test can be reduced to four. Furthermore, compared to approaches using a two-beam interferometer as a filter for the broadband light source, the visibility of the fringe system is considerably higher if a Fabry-Perot filter is applied.