Recent progress on high-speed optical transmission

Directory of Open Access Journals (Sweden)

Jianjun Yu

2016-05-01

Full Text Available The recently reported high spectral efficiency (SE and high-baud-rate signal transmission are all based on digital coherent optical communications and digital signal processing (DSP. DSP simplifies the reception of advanced modulation formats and also enables the major electrical and optical impairments to be processed and compensated in the digital domain, at the transmitter or receiver side. In this paper, we summarize the research progress on high-speed signal generation and detection and also show the progress on DSP for high-speed signal detection. We also report the latest progress on multi-core and multi-mode multiplexing.

CTD and fluorometer data were collected in the Gulf of Alaska as part of the GLobal Ocean Ecosystem dynamiCs (GLOBEC) project from 05 March 2002 to 11 December 2002 (NODC Accession 0001062)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — CTD and fluorometer data were collected using CTD and fluorometer from the R/V ALPHA HELIX in the Gulf of Alaska and Prince Williams Sound from March 5, to December...

The 1989 progress report: applied optics

International Nuclear Information System (INIS)

Antonetti, A.

1989-01-01

The 1989 progress report of the laboratory of Applied Optics of the Polytechnic School (France) is presented. The research programs are carried out in the following fields: Ultrafast Physics, including the development of femtoseconds laser sources and their utilization in Physics, Biology and Physical Chemistry; physics of infrared lasers and their applications in space and industries; Guided Optics, including investigations and construction of fiber optics couplers; biomedical studies on muscle mechanics and laser applications. The published papers, the conferences and the Laboratory staff are listed [fr

Progress In Optical Memory Technology

Science.gov (United States)

Tsunoda, Yoshito

1987-01-01

More than 20 years have passed since the concept of optical memory was first proposed in 1966. Since then considerable progress has been made in this area together with the creation of completely new markets of optical memory in consumer and computer application areas. The first generation of optical memory was mainly developed with holographic recording technology in late 1960s and early 1970s. Considerable number of developments have been done in both analog and digital memory applications. Unfortunately, these technologies did not meet a chance to be a commercial product. The second generation of optical memory started at the beginning of 1970s with bit by bit recording technology. Read-only type optical memories such as video disks and compact audio disks have extensively investigated. Since laser diodes were first applied to optical video disk read out in 1976, there have been extensive developments of laser diode pick-ups for optical disk memory systems. The third generation of optical memory started in 1978 with bit by bit read/write technology using laser diodes. Developments of recording materials including both write-once and erasable have been actively pursued at several research institutes. These technologies are mainly focused on the optical memory systems for computer application. Such practical applications of optical memory technology has resulted in the creation of such new products as compact audio disks and computer file memories.

The 1989 progress report: quantum optics

International Nuclear Information System (INIS)

Flytzanis, C.

1989-01-01

The 1989 progress report of the laboratory of Quantum Optics of the Polytechnic School (France) is presented. The main research activity of the Laboratory is the study of processes controlling the behavior of matter under the action of high intensity light fields and under space-time constraints. The reported investigations were performed in the following fields: dynamics and vibrational relaxation modes in dense phases; nonlinear optical properties of composite materials; surface energy transfer and distribution in molecule surface interactions. Techniques relating to femtosecond impulsions, pulsating Raman and nonlinear optics were developed. The published papers, the conferences and the Laboratory staff are listed [fr

Methods and Best Practice to Intercompare Dissolved Oxygen Sensors and Fluorometers/Turbidimeters for Oceanographic Applications

Directory of Open Access Journals (Sweden)

Sara Pensieri

2016-05-01

Full Text Available In European seas, ocean monitoring strategies in terms of key parameters, space and time scale vary widely for a range of technical and economic reasons. Nonetheless, the growing interest in the ocean interior promotes the investigation of processes such as oxygen consumption, primary productivity and ocean acidity requiring that close attention is paid to the instruments in terms of measurement setup, configuration, calibration, maintenance procedures and quality assessment. To this aim, two separate hardware and software tools were developed in order to test and simultaneously intercompare several oxygen probes and fluorometers/turbidimeters, respectively in the same environmental conditions, with a configuration as close as possible to real in-situ deployment. The chamber designed to perform chlorophyll-a and turbidity tests allowed for the simultaneous acquisition of analogue and digital signals of several sensors at the same time, so it was sufficiently compact to be used in both laboratory and onboard vessels. Methodologies and best practice committed to the intercomparison of dissolved oxygen sensors and fluorometers/turbidimeters have been used, which aid in the promotion of interoperability to access key infrastructures, such as ocean observatories and calibration facilities. Results from laboratory tests as well as field tests in the Mediterranean Sea are presented.

Fiber-optic filter fluorometer for emission detection of Protoporphyrin IX and its direct precursors - A preliminary study for improved Photodynamic Therapy applications

Science.gov (United States)

Landes, Rainer; Illanes, Alfredo; van Oepen, Alexander; Goeppner, Daniela; Gollnick, Harald; Friebe, Michael

2018-03-01

In this work we present first results of a laboratory manufactured filter-fluorometer to study differences in intensity and position of the main peaks of three porphyrins that appear during the Heme-Synthesis. Porphyrins play a major role in Photodynamic Therapy (PDT) for cancer treatment. Within the Heme-Synthesis, Porphyrins such as Protoporphyrin IX (PPIX) and its two precursors Coproporphyrin III (CPIII) and Uroporphyrin III (UPIII) represent photochemical agents that can interact with light to show fluorescence or generate Reactive Oxygen Species (ROS) to destroy cells. A major problem that arises is determining the ideal time slot to begin treatment after drug application. Our work is meant to show a way to solve this problem by looking at concentration changes of precursors appearing in Heme-Synthesis and using these changes to predict the occurence of PPIX inside the mitochondria.

Research progress of free space coherent optical communication

Science.gov (United States)

Tan, Zhenkun; Ke, Xizheng

2018-02-01

This paper mainly introduces the research progress of free space coherent optical communication in Xi'an University of Technology. In recent years, the research on the outer modulation technology of the laser, free-space-to-fiber coupling technique, the design of transmitting and receiving optical antenna, adaptive optical technology with or without wave-front sensor, automatic polarization control technology, frequency stabilization technology, heterodyne detection technology and high speed signal processing technology. Based on the above related research, the digital signal modulation, transmission, detection and data recovery are realized by the heterodyne detection technology in the free space optical communication system, and finally the function of smooth viewing high-definition video is realized.

Progress in high index contrast integrated optics

NARCIS (Netherlands)

Baets, R.G.F.; Bienstman, P.; Bogaerts, W.; Brouckaert, J.; De Backere, P.; Dumon, P.; Roelkens, G.; Scheerlinck, S.; Smit, M.K.; Taillaert, D.; Van Campenhout, J.; Van Laere, F.; Thourhout, Van D.

2007-01-01

A large fraction of the recent innovation in integrated optics is enabled by the use of high index contrast structures and devices. The strong confinement achievable in such devices allows for dramatic performance benefits and downscaling. In this paper the progress in this field is reviewed.

Longitudinal analysis of progression in glaucoma using spectral-domain optical coherence tomography.

Science.gov (United States)

Wessel, Julia M; Horn, Folkert K; Tornow, Ralf P; Schmid, Matthias; Mardin, Christian Y; Kruse, Friedrich E; Juenemann, Anselm G; Laemmer, Robert

2013-05-01

To compare the longitudinal loss of RNFL thickness measurements by SD-OCT in healthy individuals and glaucoma patients with or without progression concerning optic disc morphology. A total of 62 eyes, comprising 38 glaucomatous eyes with open angle glaucoma and 24 healthy controls, were included in the study (Erlangen Glaucoma Registry, NTC00494923). All patients were investigated annually over a period of 3 years by Spectralis SD-OCT measuring peripapillary RNFL thickness. By masked comparative analysis of photographs, the eyes were classified into nonprogressive and progressive glaucoma cases. Longitudinal loss of RNFL thickness was compared with morphological changes of optic disc morphology. Mixed model analysis of annual OCT scans revealed an estimated annual decrease of the RNFL thickness by 2.12 μm in glaucoma eyes with progression, whereas glaucoma eyes without progression in optic disc morphology lost 1.18 μm per year in RNFL thickness (P = 0.002). The rate of change in healthy eyes was 0.60 μm and thereby also significantly lower than in glaucoma eyes with progression (P < 0.001). The intrasession variability of three successive measurements without head repositioning was 1.5 ± 0.7 μm. The loss of mean RNFL thickness exceeded the intrasession variability in 60% of nonprogressive eyes, and in 85% of progressive eyes after 3 years. LONGITUDINAL MEASUREMENTS OF RNFL THICKNESS USING SD-OCT SHOW A MORE PRONOUNCED REDUCTION OF RNFL THICKNESS IN PATIENTS WITH PROGRESSION COMPARED WITH PATIENTS WITHOUT PROGRESSION IN GLAUCOMATOUS OPTIC DISC CHANGES. (www.clinicaltrials.gov number, NTC00494923.).

Color Doppler imaging of the retrobulbar circulation in progressive glaucoma optic neuropathy.

Science.gov (United States)

Magureanu, Marineta; Stanila, Adriana; Bunescu, Liviu Valentin; Armeanu, Cristina

2016-01-01

It is known that elevated intraocular pressure (IOP) is the primary risk factor for glaucoma. Recently, more and more evidences have shown that the vascular deficit also plays an important role in the pathogenesis and progressions of glaucomatous optic neuropathy. This issue is backed up by glaucomatous optic neuropathy (GON) cases drug compensated in which the progression of the disease in one or both eyes is ascertained despite a normal and relatively constant IOP. The present study evaluated the hemodynamic parameters in the retrobulbar circulation in patients with progressive glaucomatous optic neuropathy in one eye, who received compensated medication. The hemodynamic parameters (PSV, EDV, IR) were measured by using color Doppler ultrasound and progression was evaluated by a repeated automated perimetry. The obtained values were statistically analyzed and compared with those obtained for the stable eye.

In-situ Fluorometers Reveal High Frequency Dynamics In Dissolved Organic Matter For Urban Rivers

Science.gov (United States)

Croghan, D.; Bradley, C.; Khamis, K.; Hannah, D. M.; Sadler, J. P.; Van Loon, A.

2017-12-01

To-date Dissolved Organic Matter (DOM) dynamics have been quantified poorly in urban rivers, despite the substantial water quality issues linked to urbanisation. Research has been hindered by the low temporal resolution of observations and over-reliance on manual sampling which often fail to capture precipitation events and diurnal dynamics. High frequency data are essential to estimate more accurately DOM fluxes/loads and to understand DOM furnishing and transport processes. Recent advances in optical sensor technology, including field deployable in-situ fluorometers, are yielding new high resolution DOM information. However, no consensus regarding the monitoring resolution required for urban systems exists, with no studies monitoring at lower temporal resolution monitoring. High temporal variation occurs during storm events in TLF and HLF intensity: TLF intensity is highest during the rising limb of the hydrograph and can rapidly decline thereafter, indicating the importance of fast flow-path and close proximity sources to TLF dynamics. HLF intensity tracks discharge more closely, but can also quickly decline during high flow events due to dilution effects. Furthermore, the ratio of TLF:HLF when derived at high-frequency provides a useful indication of the presence and type of organic effluents in stream, which aids in the identification of Combined Sewage Overflow releases. Our work highlights the need for future studies to utilise shorter temporal scales than previously used to monitor urban DOM dynamics. The application of higher frequency monitoring enables the identification of finer-scale patterns and subsequently aids in deciphering the sources and pathways controlling urban DOM dynamics.

Eat-by-light fiber-optic and micro-optic devices for food quality and safety assessment

Science.gov (United States)

Mignani, A. G.; Ciaccheri, L.; Cucci, C.; Mencaglia, A. A.; Cimato, A.; Attilio, C.; Thienpont, H.; Ottevaere, H.; Paolesse, R.; Mastroianni, M.; Monti, D.; Buonocore, G.; Del Nobile, A.; Mentana, A.; Grimaldi, M. F.; Dall'Asta, C.; Faccini, A.; Galaverna, G.; Dossena, A.

2007-06-01

A selection is presented of fiber-optic and micro-optic devices that have been designed and tested for guaranteeing the quality and safety of typical foods, such as extra virgin olive oil, beer, and milk. Scattered colorimetry is used to authenticate various types of extra virgin olive oil and beer, while a fiber-optic-based device for UV-VIS-NIR absorption spectroscopy is exploited in order to obtain the hyperspectral optical signature of olive oil. This is done not only for authentication purposes, but also so as to correlate the spectral data with the content of fatty acids, which are important nutritional factors. A micro-optic sensor for the detection of olive oil aroma that is capable of distinguishing different ageing levels of extra virgin olive oil is also presented. It shows effective potential for acting as a smart cap of bottled olive oil in order to achieve a non-destructive olfactory perception of oil ageing. Lastly, a compact portable fluorometer for the rapid monitoring of the carcinogenic M1 aflatoxin in milk, is experimented.

Eat-by-light: fiber-optic and micro-optic devices for food safety and quality assessment

Science.gov (United States)

Mignani, A. G.; Ciaccheri, L.; Cucci, C.; Mencaglia, A. A.; Cimato, A.; Attilio, C.; Thienpont, H.; Ottevaere, H.; Paolesse, R.; Mastroianni, M.; Monti, D.; Buonocore, G.; Del Nobile, A.; Mentana, A.; Dall'Asta, C.; Faccini, A.; Galaverna, G.; Dossena, A.

2007-07-01

A selection of fiber-optic and micro-optic devices is presented designed and tested for monitoring the quality and safety of typical foods, namely the extra virgin olive oil, the beer, and the milk. Scattered colorimetry is used for the authentication of various types of extra virgin olive oil and beer, while a fiber-optic-based device for UV-VIS-NIR absorption spectroscopy is exploited in order to obtain the hyperspectral optical signature of olive oil. This is done not only for authentication purposes, but also so as to correlate the spectral data with the content of fatty acids that are important nutritional factors. A micro-optic sensor for the detection of olive oil aroma is presented. It is capable of distinguishing different ageing levels of extra virgin olive oil. It shows effective potential for acting as a smart cap of bottled olive oil in order to achieve a non-destructive olfactory perception of oil ageing. Lastly, a compact portable fluorometer is experimented for the rapid monitoring of the carcinogenic M1 aflatoxin in milk.

Measurement of phytoplankton photosynthesis rate using a pump-and-probe fluorometer

Directory of Open Access Journals (Sweden)

Taras K. Antal

2001-09-01

Full Text Available In this work we have studied the possibility of determining the rate of phytoplankton photosynthesis in situ using a submersible pump-and-probe fluorometer in water areas differing in their trophic level, as well as in climatic and hydrophysical characteristics. A biophysical model was used to describe the relationship between photosynthesis, underwater irradiance, and the intensity of phytoplankton fluorescence excited by an artificial light source. Fluorescence intensity was used as a measure of light absorption by phytoplankton and for assessing the efficiency of photochemical energy conversion at photosynthetic reaction centers. Parameters of the model that could not be measured experimentally were determined by calibrating fluorescence and irradiance data against the primary production measured in the Baltic Sea with the radioactive carbon method. It was shown that the standard deviation of these parameters in situ did not exceed 20%, and the use of their mean values to estimate the phytoplankton photosynthetic rate showed a good correlation between the calculated and meas

Fiber-optic filter fluorometer for emission detection of Protoporphyrin IX and its direct precursors – A preliminary study for improved Photodynamic Therapy applications

Directory of Open Access Journals (Sweden)

Rainer Landes

2018-03-01

Full Text Available In this work we present first results of a laboratory manufactured filter-fluorometer to study differences in intensity and position of the main peaks of three porphyrins that appear during the Heme-Synthesis. Porphyrins play a major role in Photodynamic Therapy (PDT for cancer treatment. Within the Heme-Synthesis, Porphyrins such as Protoporphyrin IX (PPIX and its two precursors Coproporphyrin III (CPIII and Uroporphyrin III (UPIII represent photochemical agents that can interact with light to show fluorescence or generate Reactive Oxygen Species (ROS to destroy cells. A major problem that arises is determining the ideal time slot to begin treatment after drug application. Our work is meant to show a way to solve this problem by looking at concentration changes of precursors appearing in Heme-Synthesis and using these changes to predict the occurence of PPIX inside the mitochondria. 2000 MSC: 41A05, 41A10, 65D05, 65D17, Keywords: Photodynamic Therapy, Drug light interval, Protoporphyrin IX, Coproporphyrin III, Uroporphyrin III

Progress in Nano-Electro-Optics III Industrial Applications and Dynamics of the Nano-Optical System

CERN Document Server

Ohtsu, Motoichi

2005-01-01

This unique monograph series "Progress in Nano-Electro Optics" reviews the results of advanced studies of electro-optics on the nanometric scale. This third volume covers the most recent topics of theoretical and experimental interest including classical and quantum optics, organic and inorganic material science and technology, surface science, spectroscopy, atom manipulation, photonics, and electronics. Each chapter is written by one or more leading scientists from the relevant field. Thus, high-quality scientific and technical information is provided to scientists, engineers, and students engaged in nano-electro optics and nanophotonics research. The first two volumes addressed the "Basics and Theory of Near Field Optics" (2002) and "Novel Devices and Atom Manipulation" (2003).

Photon-counting 1.0 GHz-phase-modulation fluorometer

International Nuclear Information System (INIS)

Mizuno, T.; Nakao, S.; Mizutani, Y.; Iwata, T.

2015-01-01

We have constructed an improved version of a photon-counting phase-modulation fluorometer (PC-PMF) with a maximum modulation frequency of 1.0 GHz, where a phase domain measurement is conducted with a time-correlated single-photon-counting electronics. While the basic concept of the PC-PMF has been reported previously by one of the authors, little attention has been paid to its significance, other than its weak fluorescence measurement capability. Recently, we have recognized the importance of the PC-PMF and its potential for fluorescence lifetime measurements. One important aspect of the PC-PMF is that it enables us to perform high-speed measurements that exceed the frequency bandwidths of the photomultiplier tubes that are commonly used as fluorescence detectors. We describe the advantages of the PC-PMF and demonstrate its usefulness based on fundamental performance tests. In our new version of the PC-PMF, we have used a laser diode (LD) as an excitation light source rather than the light-emitting diode that was used in the primary version. We have also designed a simple and stable LD driver to modulate the device. Additionally, we have obtained a sinusoidal histogram waveform that has multiple cycles within a time span to be measured, which is indispensable for precise phase measurements. With focus on the fluorescence intensity and the resolution time, we have compared the performance of the PC-PMF with that of a conventional PMF using the analogue light detection method

Photon-counting 1.0 GHz-phase-modulation fluorometer

Energy Technology Data Exchange (ETDEWEB)

Mizuno, T.; Nakao, S.; Mizutani, Y.; Iwata, T., E-mail: iwata@tokushima-u.ac.jp [Division of Energy System, Institute of Technology and Science, Tokushima University, 2-1 Minami-Jyosanjima, Tokushima 770-8506 (Japan)

2015-04-15

We have constructed an improved version of a photon-counting phase-modulation fluorometer (PC-PMF) with a maximum modulation frequency of 1.0 GHz, where a phase domain measurement is conducted with a time-correlated single-photon-counting electronics. While the basic concept of the PC-PMF has been reported previously by one of the authors, little attention has been paid to its significance, other than its weak fluorescence measurement capability. Recently, we have recognized the importance of the PC-PMF and its potential for fluorescence lifetime measurements. One important aspect of the PC-PMF is that it enables us to perform high-speed measurements that exceed the frequency bandwidths of the photomultiplier tubes that are commonly used as fluorescence detectors. We describe the advantages of the PC-PMF and demonstrate its usefulness based on fundamental performance tests. In our new version of the PC-PMF, we have used a laser diode (LD) as an excitation light source rather than the light-emitting diode that was used in the primary version. We have also designed a simple and stable LD driver to modulate the device. Additionally, we have obtained a sinusoidal histogram waveform that has multiple cycles within a time span to be measured, which is indispensable for precise phase measurements. With focus on the fluorescence intensity and the resolution time, we have compared the performance of the PC-PMF with that of a conventional PMF using the analogue light detection method.

Optically pumped polarized 23Na vapor target for use in polarized ion source. Technical progress report

International Nuclear Information System (INIS)

Anderson, L.W.

1984-01-01

We are currently measuring relaxation times in an optically pumped 23 Na vapor target. Our research is directed toward improvements in the optically pumped Na vapor targets used for the production of polarized H - ions. In this progress report we review the properties of the optically pumped polarized H - ion source and especially the optically pumped Na vapor target employed in this source as well as discussing the progress of our research on relaxation times in an optically pumped Na vapor target. 30 references, 6 figures, 3 tables

Estimation of chromophoric dissolved organic matter (CDOM) and photosynthetic activity of estuarine phytoplankton using a multiple-fixed-wavelength spectral fluorometer.

Science.gov (United States)

Goldman, Emily A; Smith, Erik M; Richardson, Tammi L

2013-03-15

The utility of a multiple-fixed-wavelength spectral fluorometer, the Algae Online Analyser (AOA), as a means of quantifying chromophoric dissolved organic matter (CDOM) and phytoplankton photosynthetic activity was tested using algal cultures and natural communities from North Inlet estuary, South Carolina. Comparisons of AOA measurements of CDOM to those by spectrophotometry showed a significant linear relationship, but increasing amounts of background CDOM resulted in progressively higher over-estimates of chromophyte contributions to a simulated mixed algal community. Estimates of photosynthetic activity by the AOA at low irradiance (≈ 80 μmol quanta m(-2) s(-1)) agreed well with analogous values from the literature for the chlorophyte, Dunaliella tertiolecta, but were substantially lower than previous measurements of the maximum quantum efficiency of photosystem II (F(v)/F(m)) in Thalassiosira weissflogii (a diatom) and Rhodomonas salina (a cryptophyte). When cells were exposed to high irradiance (1500 μmol quanta m(-2) s(-1)), declines in photosynthetic activity with time measured by the AOA mirrored estimates of cellular fluorescence capacity using the herbicide 3'-(3, 4-dichlorophenyl)-1',1'-dimethyl urea (DCMU). The AOA shows promise as a tool for the continuous monitoring of phytoplankton community composition, CDOM, and the group-specific photosynthetic activity of aquatic ecosystems. Copyright © 2012 Elsevier Ltd. All rights reserved.

A joint estimation detection of Glaucoma progression in 3D spectral domain optical coherence tomography optic nerve head images

Science.gov (United States)

Belghith, Akram; Bowd, Christopher; Weinreb, Robert N.; Zangwill, Linda M.

2014-03-01

Glaucoma is an ocular disease characterized by distinctive changes in the optic nerve head (ONH) and visual field. Glaucoma can strike without symptoms and causes blindness if it remains without treatment. Therefore, early disease detection is important so that treatment can be initiated and blindness prevented. In this context, important advances in technology for non-invasive imaging of the eye have been made providing quantitative tools to measure structural changes in ONH topography, an essential element for glaucoma detection and monitoring. 3D spectral domain optical coherence tomography (SD-OCT), an optical imaging technique, has been commonly used to discriminate glaucomatous from healthy subjects. In this paper, we present a new framework for detection of glaucoma progression using 3D SD-OCT images. In contrast to previous works that the retinal nerve fiber layer (RNFL) thickness measurement provided by commercially available spectral-domain optical coherence tomograph, we consider the whole 3D volume for change detection. To integrate a priori knowledge and in particular the spatial voxel dependency in the change detection map, we propose the use of the Markov Random Field to handle a such dependency. To accommodate the presence of false positive detection, the estimated change detection map is then used to classify a 3D SDOCT image into the "non-progressing" and "progressing" glaucoma classes, based on a fuzzy logic classifier. We compared the diagnostic performance of the proposed framework to existing methods of progression detection.

Comparison of Glaucoma Progression Detection by Optical Coherence Tomography and Visual Field.

Science.gov (United States)

Zhang, Xinbo; Dastiridou, Anna; Francis, Brian A; Tan, Ou; Varma, Rohit; Greenfield, David S; Schuman, Joel S; Huang, David

2017-12-01

To compare longitudinal glaucoma progression detection using optical coherence tomography (OCT) and visual field (VF). Validity assessment. We analyzed subjects with more than 4 semi-annual follow-up visits (every 6 months) in the multicenter Advanced Imaging for Glaucoma Study. Fourier-domain optical coherence tomography (OCT) was used to map the thickness of the peripapillary retinal nerve fiber layer (NFL) and ganglion cell complex (GCC). OCT-based progression detection was defined as a significant negative trend for either NFL or GCC. VF progression was reached if either the event or trend analysis reached significance. The analysis included 356 glaucoma suspect/preperimetric glaucoma (GS/PPG) eyes and 153 perimetric glaucoma (PG) eyes. Follow-up length was 54.1 ± 16.2 months for GS/PPG eyes and 56.7 ± 16.0 for PG eyes. Progression was detected in 62.1% of PG eyes and 59.8% of GS/PPG eyes by OCT, significantly (P glaucoma. While the utility of NFL declines in advanced glaucoma, GCC remains a sensitive progression detector from early to advanced stages. Copyright © 2017 Elsevier Inc. All rights reserved.

Applications of optical fiber to the remote fluorescence analysis

International Nuclear Information System (INIS)

Shin, Jang Soo; Kim, Duck Hueon; Lee, Soo Ho

1992-12-01

The laser fluorometer developed in 1987 has been used in real circumstances for trace uranium analysis. And, we have been trying to improve the instrument to be able to apply in analytical circumstances of remote measurement using optical fiber. The N 2 laser beam and the resulting fluorescence light could be successfully transmitted through a quartz-made optical fiber. The wavelength resolution and the fluorescence decay time resolution induced by pulsed N 2 laser were used to the uranium fluorescence analyses. The fluorescence of uranium in nitric acid medium was measured successfully using the system. The fluorescence signal was analysed using simplex method which is useful to deconvolute the mixed signals. An analytical method using thermal lens effect was developed. The method will be a complementary one for the fluorescence measurement. (Author)

Progression of asymptomatic optic disc swelling to non-arteritic anterior ischaemic optic neuropathy.

Science.gov (United States)

Subramanian, Prem S; Gordon, Lynn K; Bonelli, Laura; Arnold, Anthony C

2017-05-01

The time of onset of optic disc swelling in non-arteritic anterior ischaemic optic neuropathy (NAION) is not known, and it is commonly assumed to arise simultaneously with vision loss. Our goal is to report the presence and persistence of optic disc swelling without initial vision loss and its subsequent evolution to typical, symptomatic NAION. Clinical case series of patients with optic disc swelling and normal visual acuity and visual fields at initial presentation who progressed to have vision loss typical of NAION. All subjects underwent automated perimetry, disc photography and optic coherence tomography and/or fluorescein angiography to evaluate optic nerve function and perfusion. Four patients were found to have sectoral or diffuse optic disc swelling without visual acuity or visual field loss; the fellow eye of all four had either current or prior NAION or a 'disc at risk' configuration. Over several weeks of clinical surveillance, each patient experienced sudden onset of visual field and/or visual acuity loss typical for NAION. Current treatment options for NAION once vision loss occurs are limited and may not alter the natural history of the disorder. Subjects with NAION may have disc swelling for 2-10 weeks prior to the occurrence of visual loss, and with the development of new therapeutic agents, treatment at the time of observed disc swelling could prevent vision loss from NAION. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

Phaeopigments, chemical, and other data from salinometer, fluorometer, and other instruments in the Coastal Waters of Hawaii as part of the Mamala Bay Study project, 01 January 1989 - 31 December 1994 (NODC Accession 9800089)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Phaeopigments, chemical, and other data were collected using salinometer, fluorometer, and other instruments in the Coastal Waters of Hawaii from January 1, 1989 to...

Usefulness of optic nerve ultrasound to predict clinical progression in multiple sclerosis.

Science.gov (United States)

Pérez Sánchez, S; Eichau Madueño, S; Rus Hidalgo, M; Domínguez Mayoral, A M; Vilches-Arenas, A; Navarro Mascarell, G; Izquierdo, G

2018-03-21

Progressive neuronal and axonal loss are considered the main causes of disability in patients with multiple sclerosis (MS). The disease frequently involves the visual system; the accessibility of the system for several functional and structural tests has made it a model for the in vivo study of MS pathogenesis. Orbital ultrasound is a non-invasive technique that enables various structures of the orbit, including the optic nerve, to be evaluated in real time. We conducted an observational, ambispective study of MS patients. Disease progression data were collected. Orbital ultrasound was performed on all patients, with power set according to the 'as low as reasonably achievable' (ALARA) principle. Optical coherence tomography (OCT) data were also collected for those patients who underwent the procedure. Statistical analysis was conducted using SPSS version 22.0. Disease progression was significantly correlated with ultrasound findings (P=.041 for the right eye and P=.037 for the left eye) and with Expanded Disability Status Scale (EDSS) score at the end of the follow-up period (P=.07 for the right eye and P=.043 for the left eye). No statistically significant differences were found with relation to relapses or other clinical variables. Ultrasound measurement of optic nerve diameter constitutes a useful, predictive factor for the evaluation of patients with MS. Smaller diameters are associated with poor clinical progression and greater disability (measured by EDSS). Copyright © 2018 Sociedad Española de Neurología. Publicado por Elsevier España, S.L.U. All rights reserved.

Research and development on optically pumped polarized ion sources. Technical progress report, February 1, 1985-January 31, 1986

International Nuclear Information System (INIS)

Anderson, L.W.

1985-07-01

During the past year we have studied the relaxation times in an optically pumped 23 Na vapor target, studied the effects of radiation trapping on the polarization in a Na vapor target, and have studied the effects of spin exchange collisions on a beam of fast H 0 atoms as they pass through a polarized alkali target. This research is directed toward improvements in the optically pumped Na or other alkali vapor targets used for the production of polarized H - ions. In this progress report we review the properties of the optically pumped polarized H - ion source as well as discussing the progress of our research on optically pumped Na or other alkali vapor targets. 81 refs., 9 figs

Multi-optical-axis measurement of freeform progressive addition lenses using a Hartmann-Shack wavefront sensor

Science.gov (United States)

Xiang, Huazhong; Guo, Hang; Fu, Dongxiang; Zheng, Gang; Zhuang, Songlin; Chen, JiaBi; Wang, Cheng; Wu, Jie

2018-05-01

To precisely measure the whole-surface characterization of freeform progressive addition lenses (PALs), considering the multi-optical-axis conditions is becoming particularly important. Spherical power and astigmatism (cylinder) measurements for freeform PALs, using a Hartmann-Shack wavefront sensor (HSWFS) are proposed herein. Conversion formulas for the optical performance results were provided as HSWFS Zernike polynomial expansions. For each selected zone, the studied PALs were placed and tilted to simulate the multi-optical-axis conditions. The results of two tested PALs were analyzed using MATLAB programs and represented as contour plots of the spherical equivalent and cylinder of the whole-surface. The proposed experimental setup can provide a high accuracy as well as a possibility of choosing 12 lines and positions of 193 measurement zones on the entire surface. This approach to PAL analysis is potentially an efficient and useful method to objectively evaluate the optical performances, in which the full lens surface is defined and expressed as the contour plots of power in different regions (i.e., the distance region, progressive region, and near region) of the lens for regions of interest.

Physical and biological data collected with CDT, fluorometer, and SeaSoar aboard the ship WECOMA as part of Global Ocean Ecosystem Dynamics (GLOBEC) in the North Pacific Ocean from May 30 to June 16 2000 (NODC Accession 0000986)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Physical and biological data collected with CDT, fluorometer, and SeaSoar aboard the ship WECOMA in the North Pacific Ocean from May 30 to June 16 2000. These data...

Orion Optical Navigation Progress Toward Exploration Mission 1

Science.gov (United States)

Holt, Greg N.; D'Souza, Christopher N.; Saley, David

2018-01-01

Optical navigation of human spacecraft was proposed on Gemini and implemented successfully on Apollo as a means of autonomously operating the vehicle in the event of lost communication with controllers on Earth. The Orion emergency return system utilizing optical navigation has matured in design over the last several years, and is currently undergoing the final implementation and test phase in preparation for Exploration Mission 1 (EM-1) in 2019. The software development is past its Critical Design Review, and is progressing through test and certification for human rating. The filter architecture uses a square-root-free UDU covariance factorization. Linear Covariance Analysis (LinCov) was used to analyze the measurement models and the measurement error models on a representative EM-1 trajectory. The Orion EM-1 flight camera was calibrated at the Johnson Space Center (JSC) electro-optics lab. To permanently stake the focal length of the camera a 500 mm focal length refractive collimator was used. Two Engineering Design Unit (EDU) cameras and an EDU star tracker were used for a live-sky test in Denver. In-space imagery with high-fidelity truth metadata is rare so these live-sky tests provide one of the closest real-world analogs to operational use. A hardware-in-the-loop test rig was developed in the Johnson Space Center Electro-Optics Lab to exercise the OpNav system prior to integrated testing on the Orion vehicle. The software is verified with synthetic images. Several hundred off-nominal images are also used to analyze robustness and fault detection in the software. These include effects such as stray light, excess radiation damage, and specular reflections, and are used to help verify the tuning parameters chosen for the algorithms such as earth atmosphere bias, minimum pixel intensity, and star detection thresholds.

Primary radiotherapy in progressive optic nerve sheath meningiomas: a long-term follow-up study

NARCIS (Netherlands)

Saeed, P.; Blank, L.; Selva, D.; Wolbers, J.G.; Nowak, P.J.C.M.; Geskus, R.B.; Weis, E.; Mourits, M.P.; Rootman, J.

2010-01-01

Background/aims To report the outcome of primary radiotherapy in patients with progressive optic nerve sheath meningioma (ONSM). Methods The clinical records of all patients were reviewed in a retrospective, observational, multicentre study. Results Thirty-four consecutive patients were included.

Feasibility of using fiber optics for monitoring ground water contaminants

International Nuclear Information System (INIS)

Hirschfeld, T.; Deaton, T.; Milanovich, F.; Klainer, S.M.

1984-06-01

The report contains the results of the initial feasibility study for a research program undertaken to develop the technology needed to use fiber optics for monitoring groundwater contaminants. The technology appears especially well suited to the requirements of detection monitoring where a few indicator parameters can be measured continuously by sensors placed down small-diameter monitoring wells. Data are generated at a remote, centrally located fluorimeter, connected to the sampling sites by inexpensive optical fibers. The analytical method is laser-induced fluorescence which gives the desired sensitivity. The optrode, a chemical system and/or a mechanical device at the distal end of a fiber optic, furnishes the needed specificity. Various fiber and optrode configurations have been evaluated and their applications to groundwater monitoring are discussed. Feasibility is shown for physical measurements such as temperature, pressure and pH. Chemical detection and quantification of the actinides, inorganic and organic chlorides, sulfates, alcohols, aldehydes, pesticides and tracer materials are presented. Finally, it is shown that the need for smaller diameter wells (as compared to conventional sampling methods), and the ability to make up to 50 unattended in situ measurements, using a reasonably priced centralized fluorometer system connected to the sampling sites by inexpensive optical fibers, results in acceptable economy

DNA aptamer beacon assay for C-telopeptide and handheld fluorometer to monitor bone resorption.

Science.gov (United States)

Bruno, John Gordon; Carrillo, Maria P; Phillips, Taylor; Hanson, Douglas; Bohmann, Jonathan A

2011-09-01

A novel DNA aptamer beacon is described for quantification of a 26-amino acid C-telopeptide (CTx) of human type I bone collagen. One aptamer sequence and its reverse complement dominated the aptamer pool (31.6% of sequenced clones). Secondary structures of these aptamers were examined for potential binding pockets. Three-dimensional computer models which analyzed docking topologies and binding energies were in agreement with empirical fluorescence experiments used to select one candidate loop for beacon assay development. All loop structures from the aptamer finalists were end-labeled with TYE 665 and Iowa Black quencher for comparison of beacon fluorescence levels as a function of CTx concentration. The optimal beacon, designated CTx 2R-2h yielded a low ng/ml limit of detection using a commercially available handheld fluorometer. The CTx aptamer beacon bound full-length 26-amino acid CTx peptide, but not a shorter 8-amino acid segment of CTx peptide which is a common target for commercial CTx ELISA kits. The prototype assay was shown to detect CTx peptide from human urine after creatinine and urea were removed by size-exclusion chromatography to prevent nonspecific denaturing of the aptamer beacon. This work demonstrates the potential of aptamer beacons to be utilized for rapid and sensitive bone health monitoring in a handheld or point-of-care format.

[Progression of nerve fiber layer defects in retrobulbar optic neuritis by the macular ganglion cell complex].

Science.gov (United States)

Hong, D; Bosc, C; Chiambaretta, F

2017-11-01

Recent studies with SD OCT had shown early axonal damage to the macular ganglion cell complex (which consists of the three innermost layers of the retina: Inner Plexiform Layer [IPL], Ganglion Cell Layer [GCL], Retinal Nerve Fibre layer [RNFL]) in optic nerve pathology. Retrobulbar optic neuritis (RBON), occurring frequently in demyelinating diseases, leads to atrophy of the optic nerve fibers at the level of the ganglion cell axons, previously described in the literature. The goal of this study is to evaluate the progression of optic nerve fiber defects and macular ganglion cell complex defects with the SPECTRALIS OCT via a reproducible method by calculating a mean thickness in each quadrant after an episode of retrobulbar optic neuritis. This is a prospective monocentric observational study including 8 patients at the Clermont-Ferrand university medical center. All patients underwent ocular examination with macular and disc OCT analysis and a Goldmann visual field at the time of inclusion (onset or recurrence of RBON), at 3 months and at 6 months. Patients were 40-years-old on average at the time of inclusion. After 6 months of follow-up, there was progression of the atrophy of the macular ganglion cell complex in the affected eye on (11.5% or 11μm) predominantly inferonasally (13.9% or 16μm) and superonasally (12.9% or 14μm) while the other eye remained stable. The decrease in thickness occurred mainly in the most internal 3 layers of the retina. On average, the loss in thickness of the peripapillary RNFL was predominantly inferotemporal (24.9% or 39μm) and superotemporal (21.8% or 28μm). In 3 months of progression, the loss of optic nerve fibers is already seen on macular and disc OCT after an episode of RBON, especially in inferior quadrants in spite of the improvement in the Goldmann visual field and visual acuity. Segmentation by quadrant was used here to compare the progression of the defect by region compared to the fovea in a global and reproducible

Fundus autofluorescence and optical coherence tomography in the management of progressive outer retinal necrosis

Science.gov (United States)

Yeh, Steven; Wong, Wai T.; Weichel, Eric D.; Lew, Julie C.; Chew, Emily Y.; Nussenblatt, Robert B.

2011-01-01

A 41 year-old female patient with acquired immune deficiency syndrome (AIDS) presented with progressive nasal visual field loss in her right eye. Ophthalmic exam revealed widespread areas of retinal opacification with hemorrhage consistent with progressive outer retinal necrosis (PORN), which was confirmed by polymerase chain reaction (PCR) for varicella zoster virus (VZV) DNA. The patient was treated with intravenous and intravitreal foscarnet and ganciclovir with a resultant improvement clinically. Optical coherence tomography (OCT) and fundus autofluorescence (FAF) imaging revealed progressive changes indicative of widespread retinal pigment epithelial (RPE) and outer retinal dysfunction. OCT was useful in documenting progressive changes in macular architecture during therapy including neurosensory elevation, cystoid macular edema, and severe outer retinal necrosis, at initial exam, 1 week, and 1 month follow-up. Fundus autofluorescence revealed areas of stippled, hyperfluorescence within extensive zones of hypofluorescence, which progressed during the follow-up period. These areas appeared to represent lipofuscin or its photoreactive components within larger regions of RPE loss. The combination of OCT and FAF was useful in the characterization of the RPE and retinal anatomy in this patient with PORN. PMID:20337261

Progress on the WOM (Wavelength-shifting optical module) development for IceCube

Energy Technology Data Exchange (ETDEWEB)

Hebecker, Dustin [DESY Zeuthen (Germany)

2015-07-01

For ongoing studies for the extension of the IceCube neutrino observatory to low energies (PINGU) and high energies the noise rate of the optical modules should be decreased and the effective area increased in order to improve energy resolution and overall sensitivity. The WOM (Wavelength-shifting optical module) targets this points by expanding the capture area while decreasing the size of the PMT and thus decreasing the noise rate. Photons are first captured in an organic wavelength-shifting material (WLS) that is coated on light guiding material to guide the light to two smaller PMTs. This allows to achieve a very large collection area and reduces the noise to the order of 10 Hz in comparison to 600-800 Hz (IceCube DOM). The progress on the necessary WLS paint development and substrate selection will be presented. Also a brief status / outlook on the prototype assembly will be given.

Orion Optical Navigation Progress Toward Exploration: Mission 1

Science.gov (United States)

Holt, Greg N.; D'Souza, Christopher N.; Saley, David

2018-01-01

/Camera interlock angles. Accurate attitude information is provided by the star trackers during each pass. Figure 1 shows the various phases of lunar return navigation when the vehicle is in autonomous operation with lost ground communication. The midcourse maneuvers are placed to control the entry interface conditions to the desired corridor for safe landing. The general form of optical navigation on Orion is where still images of the Moon or Earth are processed to find the apparent angular diameter and centroid in the camera focal plane. This raw data is transformed into range and bearing angle measurements using planetary data and precise star tracker inertial attitude. The measurements are then sent to the main flight computer's Kalman filter to update the onboard state vector. The images are, of course, collected over an arc to converge the state and estimate velocity. The same basic technique was used by Apollo to satisfy loss-of-comm, but Apollo used manual crew sightings with a vehicle-integral sextant instead of autonomously processing optical imagery. The software development is past its Critical Design Review, and is progressing through test and certification for human rating. In support of this, a hardware-in-the-loop test rig was developed in the Johnson Space Center Electro-Optics Lab to exercise the OpNav system prior to integrated testing on the Orion vehicle. Figure 2 shows the rig, which the test team has dubbed OCILOT (Orion Camera In the Loop Optical Testbed). Analysis performed to date shows a delivery that satisfies an allowable entry corridor as shown in Figure 3.

Progress in nano-electro optics characterization of nano-optical materials and optical near-field interactions

CERN Document Server

Ohtsu, Motoichi

2005-01-01

This volume focuses on the characterization of nano-optical materials and optical-near field interactions. It begins with the techniques for characterizing the magneto-optical Kerr effect and continues with methods to determine structural and optical properties in high-quality quantum wires with high spatial uniformity. Further topics include: near-field luminescence mapping in InGaN/GaN single quantum well structures in order to interpret the recombination mechanism in InGaN-based nano-structures; and theoretical treatment of the optical near field and optical near-field interactions, providing the basis for investigating the signal transport and associated dissipation in nano-optical devices. Taken as a whole, this overview will be a valuable resource for engineers and scientists working in the field of nano-electro-optics.

In situ tryptophan-like fluorometers: assessing turbidity and temperature effects for freshwater applications.

Science.gov (United States)

Khamis, K; Sorensen, J P R; Bradley, C; Hannah, D M; Lapworth, D J; Stevens, R

2015-04-01

Tryptophan-like fluorescence (TLF) is an indicator of human influence on water quality as TLF peaks are associated with the input of labile organic carbon (e.g. sewage or farm waste) and its microbial breakdown. Hence, real-time measurement of TLF could be particularly useful for monitoring water quality at a higher temporal resolution than available hitherto. However, current understanding of TLF quenching/interference is limited for field deployable sensors. We present results from a rigorous test of two commercially available submersible tryptophan fluorometers (ex ∼ 285, em ∼ 350). Temperature quenching and turbidity interference were quantified in the laboratory and compensation algorithms developed. Field trials were then undertaken involving: (i) an extended deployment (28 days) in a small urban stream; and, (ii) depth profiling of an urban multi-level borehole. TLF was inversely related to water temperature (regression slope range: -1.57 to -2.50). Sediment particle size was identified as an important control on the turbidity specific TLF response, with signal amplification apparent 200 NTU for clay particles. Compensation algorithms significantly improved agreement between in situ and laboratory readings for baseflow and storm conditions in the stream. For the groundwater trial, there was an excellent agreement between laboratory and raw in situ TLF; temperature compensation provided only a marginal improvement, and turbidity corrections were unnecessary. These findings highlight the potential utility of real time TLF monitoring for a range of environmental applications (e.g. tracing polluting sources and monitoring groundwater contamination). However, in situations where high/variable suspended sediment loads or rapid changes in temperature are anticipated concurrent monitoring of turbidity and temperature is required and site specific calibration is recommended for long term, surface water monitoring.

Research Progress of Microfluidic Chips Preparation and its Optical Element

Directory of Open Access Journals (Sweden)

Feng WANG

2014-03-01

Full Text Available Microfluidic technology is the emerging technologies in researching fluid channel and related applications in the micro and nano-scale space. Microfluidic chip is a new miniaturized rapid analysis platform by microfluidic technology, it has many characteristics such as liquid flow control, minimal reagent consumption, rapid analysis, which is widely used in physics, chemistry, biology, and engineering science and other fields, it has strong interdisciplinary. This paper mainly discusses research progress of materials used for microfluidic chips and the devices based on microfluidic technology, including microfluidic chip, microfluidic optical devices, microfluidic laser preparation, microfluidic chip applications, focusing on the quasi-molecular laser processing technology and femtosecond laser processing technology in the microfluidic devices preparation, and make development prospects for it.

Recent Progress in Optical Biosensors Based on Smartphone Platforms

Science.gov (United States)

Geng, Zhaoxin; Zhang, Xiong; Fan, Zhiyuan; Lv, Xiaoqing; Su, Yue; Chen, Hongda

2017-01-01

With a rapid improvement of smartphone hardware and software, especially complementary metal oxide semiconductor (CMOS) cameras, many optical biosensors based on smartphone platforms have been presented, which have pushed the development of the point-of-care testing (POCT). Imaging-based and spectrometry-based detection techniques have been widely explored via different approaches. Combined with the smartphone, imaging-based and spectrometry-based methods are currently used to investigate a wide range of molecular properties in chemical and biological science for biosensing and diagnostics. Imaging techniques based on smartphone-based microscopes are utilized to capture microscale analysts, while spectrometry-based techniques are used to probe reactions or changes of molecules. Here, we critically review the most recent progress in imaging-based and spectrometry-based smartphone-integrated platforms that have been developed for chemical experiments and biological diagnosis. We focus on the analytical performance and the complexity for implementation of the platforms. PMID:29068375

Recent Progress in Optical Biosensors Based on Smartphone Platforms.

Science.gov (United States)

Geng, Zhaoxin; Zhang, Xiong; Fan, Zhiyuan; Lv, Xiaoqing; Su, Yue; Chen, Hongda

2017-10-25

With a rapid improvement of smartphone hardware and software, especially complementary metal oxide semiconductor (CMOS) cameras, many optical biosensors based on smartphone platforms have been presented, which have pushed the development of the point-of-care testing (POCT). Imaging-based and spectrometry-based detection techniques have been widely explored via different approaches. Combined with the smartphone, imaging-based and spectrometry-based methods are currently used to investigate a wide range of molecular properties in chemical and biological science for biosensing and diagnostics. Imaging techniques based on smartphone-based microscopes are utilized to capture microscale analysts, while spectrometry-based techniques are used to probe reactions or changes of molecules. Here, we critically review the most recent progress in imaging-based and spectrometry-based smartphone-integrated platforms that have been developed for chemical experiments and biological diagnosis. We focus on the analytical performance and the complexity for implementation of the platforms.

[Contribution of hemodynamic disturbances in magistral vessels to optic neuropathy progression and ocular tension changes in endocrine ophthalmopathy].

Science.gov (United States)

Likhvantseva, V G; Kharlap, S I; Korosteleva, E V; Solomatina, M V; Mel'nikova, M V; Budanova, S V; Regeb, A Ben; Vygodin, V A

2015-01-01

to investigate the contribution of various hemodynamic disturbances in magistral vessels to optic neuropathy (ON) progression and ocular tension changes in endocrine ophthalmopathy (EOP). A total of 39 patients (78 eyes) with subclinical EOP (clinical activity score, CAS ≤ 2) associated with Graves' disease (n = 32, 64 eyes) or autoimmune thyroiditis (n = 7, 14 eyes) were examined. Orbit echography was performed in all patients. Blood flow was assessed with a Voluson 730 PRO ultrasound diagnostic system ("Kretz", Austria) in triplex mode (B-scan, color Doppler flow mapping in combination with pulse-wave Doppler). Thus obtained hemodynamic parameters in ophthalmic artery, central retinal artery (CRA), central retinal vein (CRV), short posterior ciliary arteries (SPCA), and long posterior ciliary arteries (LPCA) were analyzed. To reveal the role of hemodynamic disturbances in the above mentioned vessels in ON progression and eye pressure maintenance, the patients were divided into 7 groups. Only those eyes, whose peripheral indices were increased by more than 25% of normal values and diastolic blood flow decreased by not less than 25%, were selected for further study. Intraocular pressure changes were evaluated by group mean (Mmean = M ± m mmHg), optic neuropathy progression--by the difference in group mean depth (dB) and number of scotomas between the first and the last visit (6 months of observation). In almost all types of perfusion disturbances, the resultant chronic ocular ischemia causes a decrease in IOP. The only exception, as shown, is simultaneous involvement of CRA, SPCA, and LPCA. The level of blood flow disturbance determines the severity of qualitative and quantitative changes in eyes with EOP-associated ON. The rate of ON progression directly correlates with baseline IOP values on day zero. Long-lasting chronic impairment of blood supply of the eyeball leads to reduction in ocular tension and progression of optic neuropathy. Combined perfusion

Recent Progress in Distributed Fiber Optic Sensors

Directory of Open Access Journals (Sweden)

Xiaoyi Bao

2012-06-01

Full Text Available Rayleigh, Brillouin and Raman scatterings in fibers result from the interaction of photons with local material characteristic features like density, temperature and strain. For example an acoustic/mechanical wave generates a dynamic density variation; such a variation may be affected by local temperature, strain, vibration and birefringence. By detecting changes in the amplitude, frequency and phase of light scattered along a fiber, one can realize a distributed fiber sensor for measuring localized temperature, strain, vibration and birefringence over lengths ranging from meters to one hundred kilometers. Such a measurement can be made in the time domain or frequency domain to resolve location information. With coherent detection of the scattered light one can observe changes in birefringence and beat length for fibers and devices. The progress on state of the art technology for sensing performance, in terms of spatial resolution and limitations on sensing length is reviewed. These distributed sensors can be used for disaster prevention in the civil structural monitoring of pipelines, bridges, dams and railroads. A sensor with centimeter spatial resolution and high precision measurement of temperature, strain, vibration and birefringence can find applications in aerospace smart structures, material processing, and the characterization of optical materials and devices.

Single agent vinorelbine in pediatric patients with progressive optic pathway glioma.

Science.gov (United States)

Cappellano, Andrea Maria; Petrilli, Antonio Sergio; da Silva, Nasjla Saba; Silva, Frederico Adolfo; Paiva, Priscila Mendes; Cavalheiro, Sergio; Bouffet, Eric

2015-01-01

The management of progressive unresectable low-grade glioma remains controversial. Treatment options have included radiotherapy, and more recently chemotherapy, usually following an initial period of observation. Within this context, we evaluated vinorelbine, a semi-synthetic vinca alkaloid that has shown evidence of activity against glioma. From July 2007 an institutional protocol with vinorelbine (30 mg/m(2) days 0, 8, 22) for a total of 18 cycles, has been conducted at IOP/GRAACC/UNIFESP for children with optic pathway glioma (OPG). The main objectives were clinical and radiological response, as well as toxicity profile. Twenty-three patients with progressive OPG with a mean age of 69 months (4-179) were enrolled. Three patients had a diagnosis of neurofibromatosis type 1. Twenty-two patients were assessable for response with an overall objective response rate of 63 %, with eight patients showing stable disease. The most important toxicity was hematologic (grade III/IV neutropenia) observed in four patients. Gastrointestinal toxicity (grade I/II vomiting) was observed in seven patients and only 1 patient showed grade I peripheral neuropathy. The median progression-free survival (PFS) was 33 months (6.9-69) with a 3 and 5 year PFS of 64 ± 19 and 37 ± 20 %, respectively, for an overall 3 and 5 year-survival of 95 ± 10 %. This study suggests that vinorelbine may be an interesting option for pediatric low-grade gliomas, showing low toxicity profile and providing a good quality of life for patients with such chronic disease.

Recent Progress in Optical Biosensors Based on Smartphone Platforms

Directory of Open Access Journals (Sweden)

Zhaoxin Geng

2017-10-01

Full Text Available With a rapid improvement of smartphone hardware and software, especially complementary metal oxide semiconductor (CMOS cameras, many optical biosensors based on smartphone platforms have been presented, which have pushed the development of the point-of-care testing (POCT. Imaging-based and spectrometry-based detection techniques have been widely explored via different approaches. Combined with the smartphone, imaging-based and spectrometry-based methods are currently used to investigate a wide range of molecular properties in chemical and biological science for biosensing and diagnostics. Imaging techniques based on smartphone-based microscopes are utilized to capture microscale analysts, while spectrometry-based techniques are used to probe reactions or changes of molecules. Here, we critically review the most recent progress in imaging-based and spectrometry-based smartphone-integrated platforms that have been developed for chemical experiments and biological diagnosis. We focus on the analytical performance and the complexity for implementation of the platforms.

Progress Toward Single-Photon-Level Nonlinear Optics in Crystalline Microcavities

Science.gov (United States)

Kowligy, Abijith S.

Over the last two decades, the emergence of quantum information science has uncovered many practical applications in areas such as communications, imaging, and sensing where harnessing quantum features of Nature provides tremendous benefits over existing methods exploiting classical physical phenomena. In this effort, one of the frontiers of research has been to identify and utilize quantum phenomena that are not susceptible to environmental and parasitic noise processes. Quantum photonics has been at the forefront of these studies because it allows room-temperature access to its inherently quantum-mechanical features, and allows leveraging the mature telecommunication industry. Accompanying the weak environmental influence, however, are also weak optical nonlinearities. Efficient nonlinear optical interactions are indispensible for many of the existing protocols for quantum optical computation and communication, e.g. high-fidelity entangling quantum logic gates rely on large nonlinear responses at the one- or few-photon-level. While this has been addressed to a great extent by interfacing photons with single quantum emitters and cold atomic gases, scalability has remained elusive. In this work, we identify the macroscopic second-order nonlinear polarization as a robust platform to address this challenge, and utilize the recent advances in the burgeoning field of optical microcavities to enhance this nonlinear response. In particular, we show theoretically that by using the quantum Zeno effect, low-noise, single-photon-level optical nonlinearities can be realized in lithium niobate whispering-gallery-mode microcavities, and present experimental progress toward this goal. Using the measured strength of the second-order nonlinear response in lithium niobate, we modeled the nonlinear system in the strong coupling regime using the Schrodinger picture framework and theoretically demonstrated that the single-photon-level operation can be observed for cavity lifetimes in

Integrated optics for nulling interferometry in the thermal infrared: progress and recent achievements

Science.gov (United States)

Barillot, M.; Barthelemy, E.; Bastard, L.; Broquin, J.-E.; Hawkins, G.; Kirschner, V.; Ménard, S.; Parent, G.; Poinsot, C.; Pradel, A.; Vigreux, C.; Zhang, S.; Zhang, X.

2017-11-01

The search for Earth-like exoplanets, orbiting in the habitable zone of stars other than our Sun and showing biological activity, is one of the most exciting and challenging quests of the present time. Nulling interferometry from space, in the thermal infrared, appears as a promising candidate technique for the task of directly observing extra-solar planets. It has been studied for about 10 years by ESA and NASA in the framework of the Darwin and TPF-I missions respectively [1]. Nevertheless, nulling interferometry in the thermal infrared remains a technological challenge at several levels. Among them, the development of the "modal filter" function is mandatory for the filtering of the wavefronts in adequacy with the objective of rejecting the central star flux to an efficiency of about 105. Modal filtering [2] takes benefit of the capability of single-mode waveguides to transmit a single amplitude function, to eliminate virtually any perturbation of the interfering wavefronts, thus making very high rejection ratios possible. The modal filter may either be based on single-mode Integrated Optics (IO) and/or Fiber Optics. In this paper, we focus on IO, and more specifically on the progress of the on-going "Integrated Optics" activity of the European Space Agency.

Semiconductor optical amplifier-based all-optical gates for high-speed optical processing

DEFF Research Database (Denmark)

Stubkjær, Kristian

2000-01-01

Semiconductor optical amplifiers are useful building blocks for all-optical gates as wavelength converters and OTDM demultiplexers. The paper reviews the progress from simple gates using cross-gain modulation and four-wave mixing to the integrated interferometric gates using cross-phase modulation....... These gates are very efficient for high-speed signal processing and open up interesting new areas, such as all-optical regeneration and high-speed all-optical logic functions...

Optical interference coatings for optics and photonics [Invited].

Science.gov (United States)

Lee, Cheng-Chung

2013-01-01

Optical interference coatings play as an important role in the progress in optics and photonics. In this article we give a minireview of the evolution of optical interference coatings from the theory, the design, to the manufacture. Some interesting but challenging topics for the future are also discussed.

Preliminary evaluation of an in vivo fluorometer to quantify algal periphyton biomass and community composition

Science.gov (United States)

Harris, Theodore D.; Graham, Jennifer L.

2015-01-01

The bbe-Moldaenke BenthoTorch (BT) is an in vivo fluorometer designed to quantify algal biomass and community composition in benthic environments. The BT quantifies total algal biomass via chlorophyll a (Chl-a) concentration and may differentiate among cyanobacteria, green algae, and diatoms based on pigment fluorescence. To evaluate how BT measurements of periphytic algal biomass (as Chl-a) compared with an ethanol extraction laboratory analysis, we collected BT- and laboratory-measured Chl-a data from 6 stream sites in the Indian Creek basin, Johnson County, Kansas, during August and September 2012. BT-measured Chl-a concentrations were positively related to laboratory-measured concentrations (R2 = 0.47); sites with abundant filamentous algae had weaker relations (R2 = 0.27). Additionally, on a single sample date, we used the BT to determine periphyton biomass and community composition upstream and downstream from 2 wastewater treatment facilities (WWTF) that discharge into Indian Creek. We found that algal biomass increased immediately downstream from the WWTF discharge then slowly decreased as distance from the WWTF increased. Changes in periphyton community structure also occurred; however, there were discrepancies between BT- and laboratory-measured community composition data. Most notably, cyanobacteria were present at all sites based on BT measurements but were present at only one site based on laboratory-analyzed samples. Overall, we found that the BT compared reasonably well with laboratory methods for relative patterns in Chl-a but not as well with absolute Chl-aconcentrations. Future studies need to test the BT over a wider range of Chl-aconcentrations, in colored waters, and across various periphyton assemblages.

Bio-optical properties of Porsnagerfjorden (Norway) waters based on data collected in 2014 and 2015

Science.gov (United States)

Białogrodzka, Jagoda; Stramska, Małgorzata; Burska, Dorota; Ficek, Dariusz; Stoń-Egiert, Joanna; Winogradow, Aleksandra

2016-04-01

Oceanographic data collected in the Arctic are valuable in view of the role of this region in the studies on global climate change and the fact that historically the number of in situ measurements is relatively low. Porsangerfjorden, Norway, is an example of oceanic basin with case 2 water according to the optical classification. Optical data from coastal seas are difficult in interpretation because the concentrations of optically important components can be high, variable, and not covarying with each other. Porsanger Fjord can be divided into three basins: inner, middle and outer, where physical and bio-optical properties of water masses differ. We collected optical data and water samples for phytoplankton pigments, dissolved organic matter, particulate (POC) and dissolved (DOC) organic carbon, and particulate inorganic carbon (PIC) during our two summer expeditions in 2014 and 2015. In this presentation we focus on data collected with WETLabs' ac-9 and ac-s spectrophotometers and ECO-Triplet and ECO-Triplet-w fluorometers. Concurrently with in situ optical measurements water samples were collected in situ and soon afterwards they were filtered in the laboratory at the station, stored and transported for further processing in Poland. Our analysis includes 146 of in situ measurements and discrete water samples: 62 of POC, 52 of PIC, 33 of DOC, 68 of dissolved organic matter and 89 of phytoplankton pigments. During our analysis we compare chlorophyll (Chl_a), dissolved organic matter (CDOM) and carbon concentrations with in situ collected inherent optical properties of sea water to find empirical proxies allowing to estimate various water component concentrations from optical data. Application of these proxies to available bio-optical data allowed us to derive spatial distribution of these water constituents and their variability. This work was funded by the Norway Grants (NCBR contract No. 201985, project NORDFLUX).

Committee on Atomic, Molecular, and Optical Sciences (CAMOS). Technical progress report ampersand continuation proposal, February 1, 1993--January 31, 1994

International Nuclear Information System (INIS)

Taylor, R.D.

1997-01-01

The Committee on Atomic, Molecular and Optical Sciences (CAMOS) of the National Research Council (NRC) is charged with monitoring the health of the field of atomic, molecular, and optical (AMO) science in the United States. Accordingly, the Committee identifies and examines both broad and specific issues affecting the field. Regular meetings, teleconferences, briefings from agencies and the scientific community, the formation of study panels to prepare reports, and special symposia are among the mechanisms used by the CAMOS to meet its charge. This progress report presents a review of CAMOS activities from February 1, 1993 to January 31, 1994. The details of prior activities are discussed in earlier progress reports. This report also includes the status of activities associated with the CAMOS study on the field that is being conducted by the Panel on the Future of Atomic, Molecular, and Optical Sciences (FAMOS). During the above period, CAMOS has continued to track and participate in, when requested, discussions on the health of the field. Much of the perspective of CAMOS has been presented in the recently-published report Research Briefing on Selected Opportunities in Atomic, Molecular, and Optical Sciences. That report has served as the basis for briefings to representatives of the federal government as well as the community-at-large. In keeping with its charge to monitor the health of the field, CAMOS launched a study designed to highlight future directions of the field

Recent progress in distributed optical fiber Raman photon sensors at China Jiliang University

Science.gov (United States)

Zhang, Zaixuan; Wang, Jianfeng; Li, Yi; Gong, Huaping; Yu, Xiangdong; Liu, Honglin; Jin, Yongxing; Kang, Juan; Li, Chenxia; Zhang, Wensheng; Zhang, Wenping; Niu, Xiaohui; Sun, Zhongzhou; Zhao, Chunliu; Dong, Xinyong; Jin, Shangzhong

2012-06-01

A brief review of recent progress in researches, productions and applications of full distributed fiber Raman photon sensors at China Jiliang University (CJLU) is presented. In order to improve the measurement distance, the accuracy, the space resolution, the ability of multi-parameter measurements, and the intelligence of full distributed fiber sensor systems, a new generation fiber sensor technology based on the optical fiber nonlinear scattering fusion principle is proposed. A series of new generation full distributed fiber sensors are investigated and designed, which consist of new generation ultra-long distance full distributed fiber Raman and Rayleigh scattering photon sensors integrated with a fiber Raman amplifier, auto-correction full distributed fiber Raman photon temperature sensors based on Raman correlation dual sources, full distributed fiber Raman photon temperature sensors based on a pulse coding source, full distributed fiber Raman photon temperature sensors using a fiber Raman wavelength shifter, a new type of Brillouin optical time domain analyzers (BOTDAs) integrated with a fiber Raman amplifier for replacing a fiber Brillouin amplifier, full distributed fiber Raman and Brillouin photon sensors integrated with a fiber Raman amplifier, and full distributed fiber Brillouin photon sensors integrated with a fiber Brillouin frequency shifter. The Internet of things is believed as one of candidates of the next technological revolution, which has driven hundreds of millions of class markets. Sensor networks are important components of the Internet of things. The full distributed optical fiber sensor network (Rayleigh, Raman, and Brillouin scattering) is a 3S (smart materials, smart structure, and smart skill) system, which is easy to construct smart fiber sensor networks. The distributed optical fiber sensor can be embedded in the power grids, railways, bridges, tunnels, roads, constructions, water supply systems, dams, oil and gas pipelines and other

Repetitive Immunosensor with a Fiber-Optic Device and Antibody-Coated Magnetic Beads for Semi-Continuous Monitoring of Escherichia coli O157:H7.

Science.gov (United States)

Taniguchi, Midori; Saito, Hirokazu; Mitsubayashi, Kohji

2017-09-19

A rapid and reproducible fiber-optic immunosensor for Escherichia coli O157:H7 ( E. coli O157:H7) was described. The biosensor consisted of a flow cell, an optical fiber with a thin Ni layer, and a PC linked fluorometer. First, the samples with E. coli O157:H7 were incubated with magnetic beads coated with anti- E. coli O157:H7 antibodies and anti- E. coli O157:H7 antibodies labeled cyanine 5 (Cy5) to make sandwich complexes. Then the Cy5-( E. coli O157:H7)-beads were injected into a flow cell and pulled to the magnetized Ni layer on the optical fiber set in the flow cell. An excitation light (λ = 635 nm) was used to illuminate the optical fiber, and the Cy5 florescent molecules facing the optical fiber were exposed to an evanescent wave from the optical fiber. The 670 nm fluorescent light was measured using a photodiode. Finally, the magnetic intensity of the Ni layer was removed and the Cy5- E. coli O157:H7-beads were washed out for the next immunoassay. E. coli O157:H7, diluted with phosphate buffer (PB), was measured from 1 × 10⁵ to 1 × 10⁷ cells/mL. The total time required for an assay was less than 15 min (except for the pretreatment process) and repeating immunoassay on one optical fiber was made possible.

Fiber optic-based fluorescence detection system for in vivo studies of exogenous chromophore pharmacokinetics

Science.gov (United States)

Doiron, Daniel R.; Dunn, J. B.; Mitchell, W. L.; Dalton, Brian K.; Garbo, Greta M.; Warner, Jon A.

1995-05-01

The detection and quantification of the concentration of exogenous chromophores in-vivo by their fluorescence is complicated by many physical and geometrical parameters. Measurement of such signals is advantageous in determining the pharmacokinetics of photosensitizers such as those used in photodynamic therapy (PDT) or to assist in the diagnosis of tissue histological state. To overcome these difficulties a ratio based fiber optic contact fluorometer has been developed. This fluorescence detection system (FDS) uses the ratio of the fluorescence emission peak of the exogenous chromophore to that of endogenous chromophores, i.e. autofluorescence, to correct for a variety of parameters affecting the magnitude of the measured signals. By doing so it also minimizes the range of baseline measurements prior to exogenous drug injection, for various tissue types. Design of the FDS and results of its testing in animals and patients using the second generation photosensitizer Tin ethyletiopurpurin (SnET2) are presented. These results support the feasibility and usefulness of the Ratio FDS system.

Vibrational and optical properties of amorphous metals: Progress report, July 1, 1987--June 30, 1988

International Nuclear Information System (INIS)

Lannin, J.S.

1988-02-01

Substantial progress has been achieved in the three areas of Raman scattering, inelastic neutron scattering and optical studies of amorphous metal alloys. In the Raman area, studies of amorphous disilicides of Ni and W, a-NiSi 2 and a-WSi 2 , were obtained that provide information on both the dynamics and short range order in the amorphous phase. Measurements of the Raman spectra have been compared to the neutron weighted densities of states of the corresponding crystalline systems. A detailed evaluation of the inelastic neutron spectra of the concentrated Ni alloy of a-Ni/sub .95/Tb/sub .05/ has recently been completed. Optical measurements of the real and imaginary parts of the dielectric function of a-Ni/sub .95/Tb/sub .05/ were also performed during this year using the technique of spectroscopic ellipsometry. Raman scattering measurements were performed on the amorphous state of the counterpart of the high temperature superconductor of crystalline YBa 2 Cu 3 O/sub x/

Optics and Fluid Dynamics Department annual progress report for 1999

DEFF Research Database (Denmark)

Hanson, Steen Grüner; Johansen, Per Michael; Lynov, Jens-Peter

2000-01-01

The Optics and Fluid Dynamics Department performs basic and applied research within the three programmes: (1) optical materials, (2) optical diagnostics and information processing and (3) plasma and fluid dynamics. The department has core competences in:optical sensors, optical materials, biooptics...

Optics and Plasma Research Department annual progress report for 2004

OpenAIRE

Bindslev, Henrik; Lynov, Jens-Peter; Pedersen, C.; Petersen, Paul Michael; Skaarup, Bitten

2005-01-01

The Optics and Plasma Research Department performs basic and applied research within three scientific programmes: (1) laser systems and optical materials, (2) optical diagnostics and information processing and (3) plasma physics and technology. Thedepartment has core competencies in optical sensors, optical materials, biophotonics, fusion plasma physics, and industrial plasma technology. The department employs key technologies in micro- and nanotechnology for optical systems, temperaturecalib...

Optics and Fluid Dynamics Department annual progress report for 2000

International Nuclear Information System (INIS)

Hanson, S.G.; Johansen, P.M.; Lynov, J.P.; Skaarup, B.

2001-05-01

The Optics and Fluid Dynamics Department performs basic and applied research within three scientific programmes: (1) optical materials, (2) optical diagnostics and information processing and (3) plasma and fluid dynamics. The department has core competence in: optical sensors, optical materials, optical storage, bio-optics, numerical modelling and information processing, non-linear dynamics and fusion plasma physics. The research is supported by several EU programmes, including EURATOM, by Danish research councils and by industry. A summary of the activities in 2000 is presented. (au)

Spatial heterogeneity in active chlorophyll fluorescence and PSII activity of coral tissues

DEFF Research Database (Denmark)

Ralph, P.J.; Gademann, R.; Larkum, A.W.D.

2002-01-01

Chlorophyll-a fluorescence was measured in six species of coral, using pulse-amplitude-modulated fluorometers employing fibre-optic probes with diameters of 8 mm, 1 mm and 140 µm. The 8-mm probe integrated responses over a large area, giving more weight to coenosarc than polyp tissue for Acropora...

Optics and Fluid Dynamics Department. Annual progress report for 2001

International Nuclear Information System (INIS)

Bindslev, H.; Hanson, S.G.; Lynov, J.P.; Petersen, P.M.; Skaarup, B.

2002-03-01

The Optics and Fluid Dynamics Department performs basic and applied research within three scientific programmes: 1) laser systems and optical materials, 2) optical diagnostics and information processing and 3) plasma and fluid dynamics. The department has core competence in: optical sensors, optical materials, optical storage, bio-optics, numerical modelling and information processing, non-linear dynamics and fusion plasma physics. The research is supported by several EU programmes, including EURATOM, by Danish research councils and by industry. A summary of the activities in 2001 is presented. (au)

Optics and Fluid Dynamics Department annual progress report for 2003

OpenAIRE

Bindslev, H.; Hanson, Steen Grüner; Lynov, Jens-Peter; Petersen, Paul Michael; Skaarup, Bitten

2004-01-01

The Optics and Fluid Dynamics Department performs basic and applied research within three scientific programmes: (1) laser systems and optical materials, (2) optical diagnostics and information processing and (3) plasma and fluid dynamics. The departmenthas core competences in: optical sensors, optical materials, optical storage, biophotonics, numerical modelling and information processing, non-linear dynamics, fusion plasma physics and plasma technology. The research is supported by several ...

Progress in studies of Electron-Cloud-Induced Optics Distortions at CESRTA

International Nuclear Information System (INIS)

Crittenden, J.A.; Calvey, J.R.; Dugan, G.F.; Kreinick, D.L.; Leong, Z.; Livezey, J.A.; Palmer, M.A.; Rubin, D.L.; Sagan, D.C.; Holtzapple, R.L.; Furman, M.A.; Penn, G.; Venturini, M.; Pivi, M.; Wang, L.; Harkay, K.

2010-01-01

The Cornell Electron Storage Ring Test Accelerator (CesrTA) program has included extensive measurements of coherent betatron tune shifts for a variety of electron and positron beam energies, bunch population levels, and bunch train configurations. The tune shifts have been shown to result primarily from the interaction of the beam with the space-charge field of the beam-induced low energy electron cloud in the vacuum chamber. Comparison to several advanced electron cloud simulation program packages has allowed determination of the sensitivity of these measurements to physical parameters characterizing the synchrotron radiation flux, the production of photoelectrons on the vacuum chamberwall, the beam emittance, lattice optics, and the secondary-electron yield model. We report on progress in understanding the cloud buildup and decay mechanisms in magnetic fields and in field-free regions, addressing quantitatively the precise determination of the physical parameters of the modeling. Validation of these models will serve as essential input in the design of damping rings for future high-energy linear colliders.

Progress making the top end optical assembly (TEOA) for the 4-meter Advanced Technology Solar Telescope

Science.gov (United States)

Canzian, Blaise; Barentine, J.; Arendt, J.; Bader, S.; Danyo, G.; Heller, C.

2012-09-01

L-3 Integrated Optical Systems (IOS) Division has been selected by the National Solar Observatory (NSO) to design and produce the Top End Optical Assembly (TEOA) for the 4-meter Advanced Technology Solar Telescope (ATST) to operate at Haleakal', Maui. ATST will perform to a very high optical performance level in a difficult thermal environment. The TEOA, containing the 0.65-meter silicon carbide secondary mirror and support, mirror thermal management system, mirror positioning and fast tip-tilt system, field stop with thermally managed heat dump, thermally managed Lyot stop, safety interlock and control system, and support frame, operates in the "hot spot" at the prime focus of the ATST and so presents special challenges. In this paper, we describe progress in the L-3 technical approach to meeting these challenges, including silicon carbide off-axis mirror design, fabrication, and high accuracy figuring and polishing all within L-3; mirror support design; the design for stray light control; subsystems for opto-mechanical positioning and high accuracy absolute mirror orientation sensing; Lyot stop design; and thermal management of all design elements to remain close to ambient temperature despite the imposed solar irradiance load.

Optics and Fluid Dynamics Department annual progress report for 2000

DEFF Research Database (Denmark)

Hanson, Steen Grüner; Johansen, Per Michael; Lynov, Jens-Peter

2001-01-01

The Optics and Fluid Dynamics Department performs basic and applied research within three scientific programmes: (1) optical materials, (2) optical diagnostics and information processing and (3) plasma and fluid dynamics. The department has corecompetences in: optical sensors, optical materials......, optical storage, biooptics, numerical modelling and information processing, non-linear dynamics and fusion plasma physics. The research is supported by several EU programmes, including EURATOM, by Danishresearch councils and by industry. A summary of the activities in 2000 is presented....

Optics and Plasma Research Department annual progress report for 2004

DEFF Research Database (Denmark)

Bindslev, Henrik; Lynov, Jens-Peter; Pedersen, C.

2005-01-01

The Optics and Plasma Research Department performs basic and applied research within three scientific programmes: (1) laser systems and optical materials, (2) optical diagnostics and information processing and (3) plasma physics and technology. Thedepartment has core competencies in optical sensors......, optical materials, biophotonics, fusion plasma physics, and industrial plasma technology. The department employs key technologies in micro- and nanotechnology for optical systems, temperaturecalibration, and infrared measurement techniques. The research is supported by several EU programmes, including...

Optics and Fluid Dynamics Department annual progress report for 2003

DEFF Research Database (Denmark)

Bindslev, H.; Hanson, Steen Grüner; Lynov, Jens-Peter

2004-01-01

The Optics and Fluid Dynamics Department performs basic and applied research within three scientific programmes: (1) laser systems and optical materials, (2) optical diagnostics and information processing and (3) plasma and fluid dynamics. The departmenthas core competences in: optical sensors......, optical materials, optical storage, biophotonics, numerical modelling and information processing, non-linear dynamics, fusion plasma physics and plasma technology. The research is supported by several EUprogrammes, including EURATOM, by Danish research councils and by industry. A summary of the activities...

Optics and Fluid Dynamics Department annual progress report for 2001

DEFF Research Database (Denmark)

Bindslev, H.; Hanson, Steen Grüner; Lynov, Jens-Peter

2002-01-01

The Optics and Fluid Dynamics Department performs basic and applied research within three scientific programmes: (1) laser systems and optical materials, (2) optical diagnostics and information processing and (3) plasma and fluid dynamics. The departmenthas core competences in: optical sensors......, optical materials, optical storage, biooptics, numerical modelling and information processing, non-linear dynamics and fusion plasma physics. The research is supported by several EU programmes, including EURATOM,by Danish research councils and by industry. A summary of the activities in 2001 is presented....

Optics and Fluid Dynamics Department annual progress report for 2002

DEFF Research Database (Denmark)

Bindslev, H.; Hanson, Steen Grüner; Lynov, Jens-Peter

2003-01-01

The Optics and Fluid Dynamics Department performs basic and applied research within three scientific programmes: (1) laser systems and optical materials (2) optical diagnostics and information processing and (3) plasma and fluid dynamics. The departmenthas core competences in: optical sensors......, optical materials, optical storage, biophotonics, numerical modelling and information processing, non-linear dynamics and fusion plasma physics. The research is supported by several EU programmes, includingEURATOM, by Danish research councils and by industry. A summary of the activities in 2002...

Swallowable fluorometric capsule for wireless triage of gastrointestinal bleeding.

Science.gov (United States)

Nemiroski, A; Ryou, M; Thompson, C C; Westervelt, R M

2015-12-07

Real-time detection of gastrointestinal bleeding remains a major challenge because there does not yet exist a minimally invasive technology that can both i) monitor for blood from an active hemorrhage and ii) uniquely distinguish it from blood left over from an inactive hemorrhage. Such a device would be an important tool for clinical triage. One promising solution, which we have proposed previously, is to inject a fluorescent dye into the blood stream and to use it as a distinctive marker of active bleeding by monitoring leakage into the gastrointestinal tract with a wireless fluorometer. This paper reports, for the first time to our knowledge, the development of a swallowable, wireless capsule with a built-in fluorometer capable of detecting fluorescein in blood, and intended for monitoring gastrointestinal bleeding in the stomach. The embedded, compact fluorometer uses pinholes to define a microliter sensing volume and to eliminate bulky optical components. The proof-of-concept capsule integrates optics, low-noise analog sensing electronics, a microcontroller, battery, and low power Zigbee radio, all into a cylindrical package measuring 11 mm × 27 mm and weighing 10 g. Bench-top experiments demonstrate wireless fluorometry with a limit-of-detection of 20 nM aqueous fluorescein. This device represents a major step towards a technology that would enable simple, rapid detection of active gastrointestinal bleeding, a capability that would save precious time and resources and, ultimately, reduce complications in patients.

Optics and Fluid Dynamics Department. Annual Progress Report for 2002

International Nuclear Information System (INIS)

Bindslev, H.; Hanson, S.G.; Lynov, J.P.; Petersen, P.M.; Skaarup, B.

2003-05-01

The Optics and Fluid Dynamics Department performs basic and applied research within three scientific programmes: (1 Laser systems and optical materials (2 Optical diagnostics and information processing and (3 Plasma and fluid dynamics. The department has core competences in: optical sensors, optical materials, optical storage, biophotonics, numerical modelling and information processing, non-linear dynamics and fusion plasma physics. The research is supported by several EU programmes, including EURATOM, by Danish research councils and by industry. A summary of the activities in 2002 is presented. (au)

Optics and Fluid Dynamics Department. Annual progress report for 2003

International Nuclear Information System (INIS)

Bindslev, H.; Hanson, S.G.; Lynov, J.P.; Petersen, P.M.; Skaarup, B.

2004-05-01

The Optics and Fluid Dynamics Department performs basic and applied research within three scientific programmes: (1 laser systems and optical materials, (2 optical diagnostics and information processing and (3 plasma and fluid dynamics. The department has core competences in: optical sensors, optical materials, optical storage, biophotonics, numerical modelling and information processing, non-linear dynamics, fusion plasma physics and plasma technology. The research is supported by several EU programmes, including EURATOM, by Danish research councils and by industry. A summary of the activities in 2003 is presented. (au)

Optics and Fluid Dynamics Department. Annual Progress Report for 2002

Energy Technology Data Exchange (ETDEWEB)

Bindslev, H; Hanson, S G; Lynov, J P; Petersen, P M; Skaarup, B

2003-05-01

The Optics and Fluid Dynamics Department performs basic and applied research within three scientific programmes: (1) Laser systems and optical materials (2) Optical diagnostics and information processing and (3) Plasma and fluid dynamics. The department has core competences in: optical sensors, optical materials, optical storage, biophotonics, numerical modelling and information processing, non-linear dynamics and fusion plasma physics. The research is supported by several EU programmes, including EURATOM, by Danish research councils and by industry. A summary of the activities in 2002 is presented. (au)

En Face Spectral-Domain Optical Coherence Tomography for the Monitoring of Lesion Area Progression in Stargardt Disease.

Science.gov (United States)

Melillo, Paolo; Testa, Francesco; Rossi, Settimio; Di Iorio, Valentina; Orrico, Ada; Auricchio, Alberto; Simonelli, Francesca

2016-07-01

We investigated the progression of Stargardt disease (STGD1) over a multiyear follow-up by evaluating the macular lesion area as computed by an automatic algorithm from spectral-domain optical coherence tomography (SD-OCT). We reviewed medical records of STGD1 patients, with a clinical and molecular diagnosis of STGD1 at a single institution, who underwent best-corrected visual acuity (BCVA), fundus photography, SD-OCT, full-field electroretinography, and, when available, fundus autofluorescence (FAF). Regression models were fitted on the selected clinical parameters; in particular, on the macular lesion area computed by SD-OCT, to evaluate the disease progression over a multiyear follow-up. The comparison between SD-OCT and FAF, available for 22 patients, showed that macular lesion area, assessed by SD-OCT, significantly correlated with the area of absent FAF (P disease, showing a significant progression over the follow-up. Our findings suggest that the evaluation of macular lesion area by en face SD-OCT, together with FAF, could drive the choice of the most amenable candidates and the most suitable area to be treated in gene therapy clinical trials.

Optics and Plasma Research Department. Annual progress report for 2004

International Nuclear Information System (INIS)

Bindslev, H.; Lynov, J.P.; Pedersen, C.; Petersen, P.M.; Skaarup, B.

2005-03-01

The Optics and Plasma Research Department performs basic and applied research within three scientific programmes: (1) laser systems and optical materials, (2) optical diagnostics and information processing and (3) plasma physics and technology. The department has core competencies in optical sensors, optical materials, biophotonics, fusion plasma physics, and industrial plasma technology. The department employs key technologies in micro- and nanotechnology for optical systems, temperature calibration, and infrared measurement techniques. The research is supported by several EU programmes, including EURATOM, by Danish research councils and by industry. A summary of the activities in 2004 is presented. (au)

Progress in surface plasmon subwavelength optics

International Nuclear Information System (INIS)

Zhang Douguo; Wang Pei; Jiao Xiaojin; Tang Lin; Lu Yonghua; Ming Hai

2005-01-01

Now great attention is being paid to the potential applications of surface plasmon polaritons (SPPs) in data storage, light generation, microscopy and bio-photonics. The authors review the properties of SPPs and topics of recent interest in surface plasmon subwavelength optics. (author)

Applied optics

International Nuclear Information System (INIS)

Orszag, A.; Antonetti, A.

1988-01-01

The 1988 progress report, of the Applied Optics laboratory, of the (Polytechnic School, France), is presented. The optical fiber activities are focused on the development of an optical gyrometer, containing a resonance cavity. The following domains are included, in the research program: the infrared laser physics, the laser sources, the semiconductor physics, the multiple-photon ionization and the nonlinear optics. Investigations on the biomedical, the biological and biophysical domains are carried out. The published papers and the congress communications are listed [fr

Advanced Optical Signal Processing using Time Lens based Optical Fourier Transformation

DEFF Research Database (Denmark)

Guan, Pengyu; Røge, Kasper Meldgaard; Lillieholm, Mads

2016-01-01

An overview of recent progress on time lens based advanced optical signal processing is presented, with a special focus on all-optical ultrafast 640 Gbit/s all-channel serial-to-parallel conversion, and scalable WDM regeneration....

Evaluation of baseline structural factors for predicting glaucomatous visual-field progression using optical coherence tomography, scanning laser polarimetry and confocal scanning laser ophthalmoscopy.

Science.gov (United States)

Sehi, M; Bhardwaj, N; Chung, Y S; Greenfield, D S

2012-12-01

The objective of this study is to assess whether baseline optic nerve head (ONH) topography and retinal nerve fiber layer thickness (RNFLT) are predictive of glaucomatous visual-field progression in glaucoma suspect (GS) and glaucomatous eyes, and to calculate the level of risk associated with each of these parameters. Participants with ≥28 months of follow-up were recruited from the longitudinal Advanced Imaging for Glaucoma Study. All eyes underwent standard automated perimetry (SAP), confocal scanning laser ophthalmoscopy (CSLO), time-domain optical coherence tomography (TDOCT), and scanning laser polarimetry using enhanced corneal compensation (SLPECC) every 6 months. Visual-field progression was assessed using pointwise linear-regression analysis of SAP sensitivity values (progressor) and defined as significant sensitivity loss of >1 dB/year at ≥2 adjacent test locations in the same hemifield at P<0.01. Cox proportional hazard ratios (HR) were calculated to determine the predictive ability of baseline ONH and RNFL parameters for SAP progression using univariate and multivariate models. Seventy-three eyes of 73 patients (43 GS and 30 glaucoma, mean age 63.2±9.5 years) were enrolled (mean follow-up 51.5±11.3 months). Four of 43 GS (9.3%) and 6 of 30 (20%) glaucomatous eyes demonstrated progression. Mean time to progression was 50.8±11.4 months. Using multivariate models, abnormal CSLO temporal-inferior Moorfields classification (HR=3.76, 95% confidence interval (CI): 1.02-6.80, P=0.04), SLPECC inferior RNFLT (per -1 μm, HR=1.38, 95% CI: 1.02-2.2, P=0.02), and TDOCT inferior RNFLT (per -1 μm, HR=1.11, 95% CI: 1.04-1.2, P=0.001) had significant HRs for SAP progression. Abnormal baseline ONH topography and reduced inferior RNFL are predictive of SAP progression in GS and glaucomatous eyes.

Comparing the detection and agreement of parapapillary atrophy progression using digital optic disk photographs and alternation flicker.

Science.gov (United States)

VanderBeek, Brian L; Smith, Scott D; Radcliffe, Nathan M

2010-09-01

Parapapillary atrophy (PPA) progression has been associated with progressive glaucoma, but has proven to be difficult to assess clinically. We compared inter- and intra-observer agreement using a novel automated alternation flicker technology and side-by-side digital photography inspection for the evaluation of PPA progression. Consecutive patients with serial digital optic nerve photographs at least 1 year apart were included. Two graders (NR, BV) masked to image chronology assessed a set of photographs for progressive PPA using predefined criteria based on reference photographs containing mild, moderate, extensive or no PPA progression. At a separate session, the graders evaluated photographs using alternation flicker (EyeIC, Narberth, PA, USA) applying the same criteria. The order of patients and technique was randomized. Graders then assessed the same set of flickers and photographs a second time with the order of presentation reversed. The main outcome measure was the assessment of progressive PPA as identified by alternation flicker and digital photography inspection. Inter- and intra-observer agreement using each technique was assessed using the kappa statistic. A bootstrap method for comparing correlated kappa coefficients was used to assess statistical significance. Serial photographs from 131 eyes of 68 patients were evaluated. Both graders identified significantly more cases of PPA progression using flicker compared to photography (27-34% vs 8-13%; both pphotographs (kappa=0.52 vs 0.18, p=0.02). Intra-observer agreement was similar for both graders (photos: kappa=0.58 vs 0.57, p=0.97; flicker: kappa=0.61 vs 0.70, p=0.37). When progression was assessed by the number of progressive quadrants identified by each grader using a weighted kappa statistic, flicker inter-observer agreement was still moderate (kappa=0.45) and significantly better (p=0.01) than photography, which showed poor agreement (kappa=0.15). Intra-observer agreement with a weighted kappa for

Capacity and Shaping in Coherent Fiber-Optic Links

DEFF Research Database (Denmark)

Estaran Tolosa, Jose Manuel; Zibar, Darko; Tafur Monroy, Idelfonso

2014-01-01

Over view of the concepts and latest progress of capacity and constellation shaping incoherent optical links.......Over view of the concepts and latest progress of capacity and constellation shaping incoherent optical links....

Optics and Fluid Dynamics Department annual progress report for 1995

Energy Technology Data Exchange (ETDEWEB)

Hanson, S.G.; Lading, L.; Lynov, J.P.; Skaarup, B. [eds.

1996-01-01

Research in the Optics and Fluid Dynamics Department has been performed within the following two programme areas: (1) optical diagnostics and information processing and (2) plasma and fluid dynamics. The optical activities are concentrated on optical materials, diagnostics and sensors. The plasma and fluid dynamics activities are concentrated on nonlinear dynamics in fluids, plasmas and optics as well as on plasma and fluid diagnostics. Scientific computing is an integral part of the work. The activities are supported by several EU programmes, including EURATOM, by research councils and by industry. A summary of the activities in 1995 is presented. (au) 36 ills., 166 refs.

Optics and Fluid Dynamics Department annual progress report for 1995

International Nuclear Information System (INIS)

Hanson, S.G.; Lading, L.; Lynov, J.P.; Skaarup, B.

1996-01-01

Research in the Optics and Fluid Dynamics Department has been performed within the following two programme areas: (1) optical diagnostics and information processing and (2) plasma and fluid dynamics. The optical activities are concentrated on optical materials, diagnostics and sensors. The plasma and fluid dynamics activities are concentrated on nonlinear dynamics in fluids, plasmas and optics as well as on plasma and fluid diagnostics. Scientific computing is an integral part of the work. The activities are supported by several EU programmes, including EURATOM, by research councils and by industry. A summary of the activities in 1995 is presented. (au) 36 ills., 166 refs

Optics and Fluid Dynamics Department annual progress report for 1997

International Nuclear Information System (INIS)

Hanson, S.G.; Johansen, P.M.; Lading, L.; Lynov, J.P.; Skaarup, B.

1998-04-01

Research in the Optics and Fluid Dynamics Department has been performed within the following three programme areas: (1) optical materials, (2) optical diagnostics and information processing and (3) plasma and fluid dynamics. The work is concentrated on combinations of systems, structures and materials. The systems work is focused on sensors, information processing and storage; the structures work is concentrated on pattern formation and diffractive elements; the materials work is centred on the understanding and utilisation of nonlinear phenomena for optical components and systems. Scientific computing is an integral part of the work. Biomedical optics is a new activity and the work on polymer optics is enhanced considerably. The activities are supported by several EU programmes, including EURATOM, by research councils and by industry. A summary of the activities in 1997 is presented. (au)

Optics and Fluid Dynamics Department annual progress report for 1997

Energy Technology Data Exchange (ETDEWEB)

Hanson, S.G.; Johansen, P.M.; Lading, L.; Lynov, J.P.; Skaarup, B. [eds.

1998-04-01

Research in the Optics and Fluid Dynamics Department has been performed within the following three programme areas: (1) optical materials, (2) optical diagnostics and information processing and (3) plasma and fluid dynamics. The work is concentrated on combinations of systems, structures and materials. The systems work is focused on sensors, information processing and storage; the structures work is concentrated on pattern formation and diffractive elements; the materials work is centred on the understanding and utilisation of nonlinear phenomena for optical components and systems. Scientific computing is an integral part of the work. Biomedical optics is a new activity and the work on polymer optics is enhanced considerably. The activities are supported by several EU programmes, including EURATOM, by research councils and by industry. A summary of the activities in 1997 is presented. (au) 1 tab., 63 ills., 249 refs.

Progress in Studies of Electron-Cloud-Induced Optics Distortions at CesrTA

International Nuclear Information System (INIS)

Crittenden, James; Penn, Gregory; Venturini, Marco; Harkay, Katherine; Holtzapple, Robert; Pivi, Mauro; Wang, Lanfa

2012-01-01

The Cornell Electron Storage Ring Test Accelerator (CesrTA) program has included extensive measurements of coherent betatron tune shifts for a variety of electron and positron beam energies, bunch population levels, and bunch train configurations. The tune shifts have been shown to result primarily from the interaction of the beam with the space-charge field of the beam-induced low-energy electron cloud in the vacuum chamber. Comparison to several advanced electron cloud simulation codes has allowed determination of the sensitivity of these measurements to physical parameters characterizing the synchrotron radiation flux, the production of photo-electrons on the vacuum chamber wall, the beam emittance, lattice optics, and the secondary-electron yield model. We report on progress in understanding the cloud buildup and decay mechanisms in magnetic fields and in field-free regions, addressing quantitatively the precise determination of the physical parameters of the modeling. Validation of these models will serve as essential input in the design of damping rings for future high-energy linear colliders.

En Face Spectral-Domain Optical Coherence Tomography for the Monitoring of Lesion Area Progression in Stargardt Disease

Science.gov (United States)

Melillo, Paolo; Testa, Francesco; Rossi, Settimio; Di Iorio, Valentina; Orrico, Ada; Auricchio, Alberto; Simonelli, Francesca

2016-01-01

Purpose We investigated the progression of Stargardt disease (STGD1) over a multiyear follow-up by evaluating the macular lesion area as computed by an automatic algorithm from spectral-domain optical coherence tomography (SD-OCT). Methods We reviewed medical records of STGD1 patients, with a clinical and molecular diagnosis of STGD1 at a single institution, who underwent best-corrected visual acuity (BCVA), fundus photography, SD-OCT, full-field electroretinography, and, when available, fundus autofluorescence (FAF). Regression models were fitted on the selected clinical parameters; in particular, on the macular lesion area computed by SD-OCT, to evaluate the disease progression over a multiyear follow-up. Results The comparison between SD-OCT and FAF, available for 22 patients, showed that macular lesion area, assessed by SD-OCT, significantly correlated with the area of absent FAF (P disease, showing a significant progression over the follow-up. Our findings suggest that the evaluation of macular lesion area by en face SD-OCT, together with FAF, could drive the choice of the most amenable candidates and the most suitable area to be treated in gene therapy clinical trials. PMID:27409479

Ultra-Wideband Optical Modulation Spectrometer (OMS) Development: Study of the Optical Setup of a Wide-Band Optical Modulation Spectrometer

Science.gov (United States)

Tolls, Volker; Stringfellow, Guy (Technical Monitor)

2001-01-01

The purpose of this study is to advance the design of the optical setup for a wide-band Optical Modulation Spectrometer (OMS) for use with astronomical heterodyne receiver systems. This report describes the progress of this investigation achieved from March until December 2001.

Changing image of correlation optics: introduction.

Science.gov (United States)

Angelsky, Oleg V; Desyatnikov, Anton S; Gbur, Gregory J; Hanson, Steen G; Lee, Tim; Miyamoto, Yoko; Schneckenburger, Herbert; Wyant, James C

2016-04-20

This feature issue of Applied Optics contains a series of selected papers reflecting recent progress of correlation optics and illustrating current trends in vector singular optics, internal energy flows at light fields, optical science of materials, and new biomedical applications of lasers.

Changing image of correlation optics: introduction

DEFF Research Database (Denmark)

Angelsky, Oleg V.; Desyatnikov, Anton S.; Gbur, Gregory J.

2016-01-01

This feature issue of Applied Optics contains a series of selected papers reflecting recent progress of correlation optics and illustrating current trends in vector singular optics, internal energy flows at light fields, optical science of materials, and new biomedical applications of lasers. (C...

Optics and Fluid Dynamics Department annual progress report for 1993

International Nuclear Information System (INIS)

Hanson, S.G.; Lading, L.; Michelsen, P.; Skaarup, B.

1994-01-01

Research in the Optics and Fluid Dynamics Department is performed within the following two programme areas: optics and continuum physics. In optics the activities are within (a) optical materials, (b) quasi-elastic light scattering and diagnostics in solids, fluids, and plasmas, and (c) optical and electronic information processing. Within continuum physics the activities are within (a) studies of non-linear dynamical processes in continuum systems, (b) investigations of problems with relevance to fusion plasma physics. The injection of pellets in fusion experiments has been investigated and pellet injectors to European fusion experiments are manufactured. The department is also responsible for the EURATOM collaboration within fusion plasma physics. A summary of activities in 1993 is presented. (au) (27 ills., 24 refs.)

Optics and fluid dynamics department annual progress report for 1994

Energy Technology Data Exchange (ETDEWEB)

Hanson, S G; Lading, L; Lynov, J P; Michelsen, P

1995-01-01

Research in the Optics and Fluid Dynamics Department is performed within the following two programme areas: optics and continuum physics. In optics the activities are within (a) optical materials and electromagnetic propagation, (b) diagnostics and sensors, and (c) information processing. In continuum physics the activities are (a) nonlinear dynamics and (b) computer physics. The activities are supported by several EU programmes, including EURATOM, by research councils, and by industry. A special activity is the implementation of pellet injectors for fusion research. A summary of activities in 1994 is presented. (au) (27 ills., 44 refs.).

Optics and fluid dynamics department annual progress report for 1994

International Nuclear Information System (INIS)

Hanson, S.G.; Lading, L.; Lynov, J.P.; Michelsen, P.

1995-01-01

Research in the Optics and Fluid Dynamics Department is performed within the following two programme areas: optics and continuum physics. In optics the activities are within (a) optical materials and electromagnetic propagation, (b) diagnostics and sensors, and (c) information processing. In continuum physics the activities are (a) nonlinear dynamics and (b) computer physics. The activities are supported by several EU programmes, including EURATOM, by research councils, and by industry. A special activity is the implementation of pellet injectors for fusion research. A summary of activities in 1994 is presented. (au) (27 ills., 44 refs.)

Progress and Opportunities in Soft Photonics and Biologically Inspired Optics.

Science.gov (United States)

Kolle, Mathias; Lee, Seungwoo

2018-01-01

Optical components made fully or partially from reconfigurable, stimuli-responsive, soft solids or fluids-collectively referred to as soft photonics-are poised to form the platform for tunable optical devices with unprecedented functionality and performance characteristics. Currently, however, soft solid and fluid material systems still represent an underutilized class of materials in the optical engineers' toolbox. This is in part due to challenges in fabrication, integration, and structural control on the nano- and microscale associated with the application of soft components in optics. These challenges might be addressed with the help of a resourceful ally: nature. Organisms from many different phyla have evolved an impressive arsenal of light manipulation strategies that rely on the ability to generate and dynamically reconfigure hierarchically structured, complex optical material designs, often involving soft or fluid components. A comprehensive understanding of design concepts, structure formation principles, material integration, and control mechanisms employed in biological photonic systems will allow this study to challenge current paradigms in optical technology. This review provides an overview of recent developments in the fields of soft photonics and biologically inspired optics, emphasizes the ties between the two fields, and outlines future opportunities that result from advancements in soft and bioinspired photonics. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Optics and fluid dynamics department annual progress report for 1992

International Nuclear Information System (INIS)

Lading, L.; Lynov, J.P.; Skaarup, B.

1993-01-01

Research in the Optics and FLuid Dynamics Department is performed within two sections. The Optics Section has activities within (a) optical materials, (b) quasielastic light scattering and diagnostics in solids, fluids and plasmas, and (c) optical and electronic information processing. The Continuum Physics Section performs (a) studies of nonlinear dynamical processes in continuum systems, (b) investigations of other problems in fusion plasma physics, and (c) develops pellet injectors for fusion experiments. Most of these activities are done in connection with the Euratom Association. A summary of activities in 1992 is presented. (au) (25 ills., 36 refs.)

Progress in planar optical waveguides

CERN Document Server

Wang, Xianping; Cao, Zhuangqi

2016-01-01

This book provides a comprehensive description of various slab waveguide structures ranged from graded-index waveguide to symmetrical metal-cladding waveguide. In this book, the transfer Matrix method is developed and applied to analyze the simplest case and the complex generalizations. A novel symmetrical metal-cladding waveguide structure is proposed and systematically investigated for several issues of interest, such as biochemical sensing, Goos-Hänchen shift and the slow light effect, etc. Besides, this book summarizes the authors’ research works on waveguides over the last decade. The readers who are familiar with basic optics theory may find this book easy to read and rather inspiring.

Commercialization and Standardization Progress Towards an Optical Communications Earth Relay

Science.gov (United States)

Edwards, Bernard L.; Israel, David J.

2015-01-01

NASA is planning to launch the next generation of a space based Earth relay in 2025 to join the current Space Network, consisting of Tracking and Data Relay Satellites in space and the corresponding infrastructure on Earth. While the requirements and architecture for that relay satellite are unknown at this time, NASA is investing in communications technologies that could be deployed to provide new communications services. One of those new technologies is optical communications. The Laser Communications Relay Demonstration (LCRD) project, scheduled for launch in 2018 as a hosted payload on a commercial communications satellite, is a critical pathfinder towards NASA providing optical communications services on the next generation space based relay. This paper will describe NASA efforts in the on-going commercialization of optical communications and the development of inter-operability standards. Both are seen as critical to making optical communications a reality on future NASA science and exploration missions. Commercialization is important because NASA would like to eventually be able to simply purchase an entire optical communications terminal from a commercial provider. Inter-operability standards are needed to ensure that optical communications terminals developed by one vendor are compatible with the terminals of another. International standards in optical communications would also allow the space missions of one nation to use the infrastructure of another.

A rare case of bilateral optic nerve sheath meningioma

Directory of Open Access Journals (Sweden)

Somen Misra

2014-01-01

Full Text Available A 60-year-old female presented with gradual, painless, progressive diminution of vision, and progressive proptosis of left eye since 7 years. Ophthalmological examination revealed mild proptosis and total optic atrophy in the left eye. Magnetic resonance imaging (MRI and computed tomography (CT brain with orbit showed bilateral optic nerve sheath meningioma (ONSM involving the intracranial, intracanalicular, intraorbital part of the optic nerve extending up to optic chiasma and left cavernous sinus.

Bio-Optics and Bio-Inspired Optical Materials.

Science.gov (United States)

Tadepalli, Sirimuvva; Slocik, Joseph M; Gupta, Maneesh K; Naik, Rajesh R; Singamaneni, Srikanth

2017-10-25

Through the use of the limited materials palette, optimally designed micro- and nanostructures, and tightly regulated processes, nature demonstrates exquisite control of light-matter interactions at various length scales. In fact, control of light-matter interactions is an important element in the evolutionary arms race and has led to highly engineered optical materials and systems. In this review, we present a detailed summary of various optical effects found in nature with a particular emphasis on the materials and optical design aspects responsible for their optical functionality. Using several representative examples, we discuss various optical phenomena, including absorption and transparency, diffraction, interference, reflection and antireflection, scattering, light harvesting, wave guiding and lensing, camouflage, and bioluminescence, that are responsible for the unique optical properties of materials and structures found in nature and biology. Great strides in understanding the design principles adapted by nature have led to a tremendous progress in realizing biomimetic and bioinspired optical materials and photonic devices. We discuss the various micro- and nanofabrication techniques that have been employed for realizing advanced biomimetic optical structures.

Progress in Nano-Electro-Optics VII Chemical, Biological, and Nanophotonic Technologies for Nano-Optical Devices and Systems

CERN Document Server

Ohtsu, Motoichi

2010-01-01

This book focuses on chemical and nanophotonic technology to be used to develop novel nano-optical devices and systems. It begins with temperature- and photo-induced phase transition of ferromagnetic materials. Further topics include: energy transfer in artificial photosynthesis, homoepitaxial multiple quantum wells in ZnO, near-field photochemical etching and nanophotonic devices based on a nonadiabatic process and optical near-field energy transfer, respectively and polarization control in the optical near-field for optical information security. Taken as a whole, this overview will be a valuable resource for engineers and scientists working in the field of nano-electro-optics.

Retinal degeneration in progressive supranuclear palsy measured by optical coherence tomography and scanning laser polarimetry.

Science.gov (United States)

Stemplewitz, Birthe; Kromer, Robert; Vettorazzi, Eik; Hidding, Ute; Frings, Andreas; Buhmann, Carsten

2017-07-13

This cross-sectional study compared the retinal morphology between patients with progressive supranuclear palsy (PSP) and healthy controls. (The retinal nerve fiber layer (RNFL) around the optic disc and the retina in the macular area of 22 PSP patients and 151 controls were investigated by spectral domain optical coherence tomography (SD-OCT). Additionally, the RNFL and the nerve fiber index (NFI) were measured by scanning laser polarimetry (SLP). Results of RNFL measurements with SD-OCT and SLP were compared to assess diagnostic discriminatory power. Applying OCT, PSP patients showed a smaller RNFL thickness in the inferior nasal and inferior temporal areas. The macular volume and the thickness of the majority of macular sectors were reduced compared to controls. SLP data showed a thinner RNFL thickness and an increase in the NFI in PSP patients. Sensitivity and specificity to discriminate PSP patients from controls were higher applying SLP than SD-OCT. Retinal changes did not correlate with disease duration or severity in any OCT or SLP measurement. PSP seems to be associated with reduced thickness and volume of the macula and reduction of the RNFL, independent of disease duration or severity. Retinal imaging with SD-OCT and SLP might become an additional tool in PSP diagnosis.

Optical Subsystems for Next Generation Access Networks

DEFF Research Database (Denmark)

Lazaro, J.A; Polo, V.; Schrenk, B.

2011-01-01

Recent optical technologies are providing higher flexibility to next generation access networks: on the one hand, providing progressive FTTx and specifically FTTH deployment, progressively shortening the copper access network; on the other hand, also opening fixed-mobile convergence solutions...... in next generation PON architectures. It is provided an overview of the optical subsystems developed for the implementation of the proposed NG-Access Networks....

Effect of disease stage on progression of hydroxychloroquine retinopathy.

Science.gov (United States)

Marmor, Michael F; Hu, Julia

2014-09-01

Hydroxychloroquine sulfate retinopathy can progress after the drug is stopped. It is not clear how this relates to the stage of retinopathy or whether early screening with modern imaging technology can prevent progression and visual loss. To determine the relationship between progression of retinopathy and the severity of disease using objective data from optical coherence tomography and assess the value of early screening for the toxic effects of hydroxychloroquine. Clinical findings in patients with hydroxychloroquine retinopathy were monitored with repeated anatomical and functional examinations for 13 to 40 months after the drug was stopped in a referral practice in a university medical center. Eleven patients participated, with the severity of toxic effects categorized as early (patchy parafoveal damage shown on field or objective testing), moderate (a 50%-100% parafoveal ring of optical coherence tomography thinning but intact retinal pigment epithelium), and severe (visible bull's-eye damage). Visual acuity, white 10-2 visual field pattern density plots, fundus autofluorescence, spectral-density optical coherence tomography cross sections, thickness (from cube diagrams), and ellipsoid zone length. Visual acuity and visual fields showed no consistent change. Fundus autofluorescence showed little or no change except in severe cases in which the bull's-eye damage expanded progressively. Optical coherence tomography cross sections showed little visible change in early and moderate cases but progressive foveal thinning (approximately 7 μm/y) and loss of ellipsoid zone (in the range of 100 μm/y) in severe cases, which was confirmed by quantitative measurements. The measurements also showed some foveal thinning (approximately 4 μm/y) and deepening of parafoveal loss in moderate cases, but the breadth of the ellipsoid zone remained constant in both early and moderate cases. A few cases showed a suggestion of ellipsoid zone improvement. Patients with

[Clinical feature of chronic compressive optic neuropathy without optic atrophy].

Science.gov (United States)

Jiang, Libin; Shi, Jitong; Liu, Wendong; Kang, Jun; Wang, Ningli

2014-12-01

To investigate the clinical feature of the chronic compressive optic neuropathy without optic atrophy. Retrospective cases series study. The clinical data of 25 patients (37 eyes) with chronic compressive optic neuropathy without optic atrophy, treated in Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, from October, 2005 to March, 2014, were collected. Those patients had been showing visual symptoms for 6 months or longer, but missed diagnosed or misdiagnosed as other eye diseases due to their normal or slightly changed fundi. The collected data including visual acuities, visual fields, neuroimaging and/or pathologic diagnosis were analyzed. Among the 25 patients, there were 5 males and 20 females, and their ages range from 9 to 74 years [average (47.5 ± 13.4) years]. All patients suffered progressive impaired vision in single eye or both eyes, without exophthalmos or abnormal eye movements. Except one patient had a headache, other patients did not show systemic symptoms. The corrected visual acuities were between HM to 1.0, and their appearances of optic discs and colors of fundi were normal. After neuroimaging and/or pathological examination, it was proven that 14 patients suffered tuberculum sellae meningiomas, 5 patients with hypophysoma, 3 patient with optic nerve sheath meningioma in orbital apex, 1 patient with cavernous hemangioma, 1 patient with vascular malformation in orbital apex and 1 patient with optic nerve glioma. Among the 19 patients whose suffered occupied lesions of saddle area, 14 patients underwent visual field examinations, and only 4 patients showed classic visual field defects caused by optic chiasmal lesions. Occult progressive visual loss was the most important clinical feature of the disease.

Functional optical coherence tomography: principles and progress

International Nuclear Information System (INIS)

Kim, Jina; Levinson, Howard; Brown, William; Maher, Jason R.; Wax, Adam

2015-01-01

In the past decade, several functional extensions of optical coherence tomography (OCT) have emerged, and this review highlights key advances in instrumentation, theoretical analysis, signal processing and clinical application of these extensions. We review five principal extensions: Doppler OCT (DOCT), polarization-sensitive OCT (PS-OCT), optical coherence elastography (OCE), spectroscopic OCT (SOCT), and molecular imaging OCT. The former three have been further developed with studies in both ex vivo and in vivo human tissues. This review emphasizes the newer techniques of SOCT and molecular imaging OCT, which show excellent potential for clinical application but have yet to be well reviewed in the literature. SOCT elucidates tissue characteristics, such as oxygenation and carcinogenesis, by detecting wavelength-dependent absorption and scattering of light in tissues. While SOCT measures endogenous biochemical distributions, molecular imaging OCT detects exogenous molecular contrast agents. These newer advances in functional OCT broaden the potential clinical application of OCT by providing novel ways to understand tissue activity that cannot be accomplished by other current imaging methodologies. (topical review)

In-situ optical and acoustical measurements of the buoyant cyanobacterium p. Rubescens: spatial and temporal distribution patterns.

Directory of Open Access Journals (Sweden)

Hilmar Hofmann

Full Text Available Optical (fluorescence and acoustic in-situ techniques were tested in their ability to measure the spatial and temporal distribution of plankton in freshwater ecosystems with special emphasis on the harmful and buoyant cyanobacterium P. rubescens. Fluorescence was measured with the multi-spectral FluoroProbe (Moldaenke FluoroProbe, MFP and a Seapoint Chlorophyll Fluorometer (SCF. In-situ measurements of the acoustic backscatter strength (ABS were conducted with three different acoustic devices covering multiple acoustic frequencies (614 kHz ADCP, 2 MHz ADP, and 6 MHz ADV. The MFP provides a fast and reliable technique to measure fluorescence at different wavelengths in situ, which allows discriminating between P. rubescens and other phytoplankton species. All three acoustic devices are sensitive to P. rubescens even if other scatterers, e.g., zooplankton or suspended sediment, are present in the water column, because P. rubescens containing gas vesicles has a strong density difference and hence acoustic contrast to the ambient water and other scatterers. After calibration, the combination of optical and acoustical measurements not only allows qualitative and quantitative observation of P. rubescens, but also distinction between P. rubescens, other phytoplankton, and zooplankton. As the measuring devices can sample in situ at high rates they enable assessment of plankton distributions at high temporal (minutes and spatial (decimeters resolution or covering large temporal (seasonal and spatial (basin scale scales.

Progress in nonlinear nano-optics

CERN Document Server

Lienau, Christoph; Grunwald, Rüdiger

2015-01-01

This book presents the state of the art in nonlinear nanostructures for ultrafast laser applications. Most recent results in two emerging fields are presented: (i) generation of laser-induced nanostructures in materials like metals, metal oxides and semiconductors, and (ii) ultrafast excitation and energy transfer in nanoscale physical, chemical and hybrid systems. Particular emphasis is laid on the up-to-date controversially discussed mechanisms of sub-wavelength ripple formation including models of self-organized material transport and multiphoton excitation channels, nonlinear optics of plasmonic structures (nanotips, nanowires, 3D-metamaterials), and energy localization and transport on ultrafast time scale and spatial nanoscale. High-resolution spectroscopy, simulation and characterization techniques are reported. New applications of ultrashort-pulsed lasers for materials processing and the use of nanostructured materials for characterizing laser fields and laser-matter-interactions are discussed.

Application Specific Optical Fibers

OpenAIRE

Pal, Bishnu P.

2010-01-01

In this chapter we have attempted to provide a unified summary description of the most important propagation characteristics of an optical fiber followed by discussion on several variety of special fibers for realizing fiber amplifiers, dispersion compensating fibers, microstructured optical fibers, and so on. Even though huge progress has been made on development of optical fibers for telecom application, a need for developing special fibers, not necessarily for telecom alone, has arisen. Th...

Sub-micrometer waveguide for nano-optics

DEFF Research Database (Denmark)

Rottwitt, Karsten; Dyndgaard, Morten Glarborg; Andersen, Karin Nordström

2003-01-01

With the recent progress within the field of processing nano structures, there is an increasing interest in coupling light into such structures both for characterization of optical properties and new optical components. In this work we propose the use of a sub-micrometer planar waveguide for prob......With the recent progress within the field of processing nano structures, there is an increasing interest in coupling light into such structures both for characterization of optical properties and new optical components. In this work we propose the use of a sub-micrometer planar waveguide...... for probing the reflection of light against a nano structure. The planar waveguide is based on a silicon nitride core layer, surrounded by a silica cladding region. In our design we utilize this waveguide to couple light into a nano-structure....

Nonlinear Optics: Principles and Applications

DEFF Research Database (Denmark)

Rottwitt, Karsten; Tidemand-Lichtenberg, Peter

of applications, Nonlinear Optics: Principles and Applications effectively bridges physics and mathematics with relevant applied material for real-world use. The book progresses naturally from fundamental aspects to illustrative examples, and presents a strong theoretical foundation that equips the reader...... and matter, this text focuses on the physical understanding of nonlinear optics, and explores optical material response functions in the time and frequency domain....

Quantum optics

Energy Technology Data Exchange (ETDEWEB)

Drummond, P D [University of Queensland, St. Lucia, QLD (Australia).Physics Department

1999-07-01

Full text: Quantum optics in Australia has been an active research field for some years. I shall focus on recent developments in quantum and atom optics. Generally, the field as a whole is becoming more and more diverse, as technological developments drive experiments into new areas, and theorists either attempt to explain the new features, or else develop models for even more exotic ideas. The recent developments include quantum solitons, quantum computing, Bose-Einstein condensation, atom lasers, quantum cryptography, and novel tests of quantum mechanics. The talk will briefly cover current progress and outstanding problems in each of these areas. Copyright (1999) Australian Optical Society.

Optics and Fluid Dynamics Department annual progress report for 1996

International Nuclear Information System (INIS)

Hanson, S.G.; Johansen, P.M.; Lading, L.; Lynov, J.P.; Skaarup, B.

1997-01-01

Research in the Optics and Fluid Dynamics Department has been performed within the following three programme areas: (1) optical materials, (2) optical diagnostics and information processing and (3) plasma and fluid dynamics. The work is concentrated on combinations of systems, structures and materials. The systems work is focused on sensors, information processing an storage; the structures work is concentrated on pattern formation and diffractive elements; the materials work is centred on the understanding and utilisation of nonlinear phenomena. Scientific computing is an integral part of the work. The activities are supported by several EU programmes, including EURATOM, by research councils and by industry. A summary of the activities in 1996 is presented. (au) 53 ills., 232 refs

Optics and Fluid Dynamics Department annual progress report for 1996

Energy Technology Data Exchange (ETDEWEB)

Hanson, S.G.; Johansen, P.M.; Lading, L.; Lynov, J.P.; Skaarup, B. [eds.

1997-01-01

Research in the Optics and Fluid Dynamics Department has been performed within the following three programme areas: (1) optical materials, (2) optical diagnostics and information processing and (3) plasma and fluid dynamics. The work is concentrated on combinations of systems, structures and materials. The systems work is focused on sensors, information processing an storage; the structures work is concentrated on pattern formation and diffractive elements; the materials work is centred on the understanding and utilisation of nonlinear phenomena. Scientific computing is an integral part of the work. The activities are supported by several EU programmes, including EURATOM, by research councils and by industry. A summary of the activities in 1996 is presented. (au) 53 ills., 232 refs.

Advances in optical imaging

International Nuclear Information System (INIS)

Bremer, C.; Ntziachristos, V.; Mahmood, U.; Tung, C.H.; Weissleder, R.

2001-01-01

Different optical imaging technologies have significantly progressed over the last years. Besides advances in imaging techniques and image reconstruction, new 'smart' optical contrast agents have been developed which can be used to detect molecular targets (such as endogenous enzymes) in vivo. The combination of novel imaging technologies coupled with smart agents bears great diagnostic potential both clinically and experimentally. This overview outlines the basic principles of optical imaging and summarizes the current state of the art. (orig.) [de

Optic nerve oxygenation

DEFF Research Database (Denmark)

Stefánsson, Einar; Pedersen, Daniella Bach; Jensen, Peter Koch

2005-01-01

The oxygen tension of the optic nerve is regulated by the intraocular pressure and systemic blood pressure, the resistance in the blood vessels and oxygen consumption of the tissue. The oxygen tension is autoregulated and moderate changes in intraocular pressure or blood pressure do not affect...... the optic nerve oxygen tension. If the intraocular pressure is increased above 40 mmHg or the ocular perfusion pressure decreased below 50 mmHg the autoregulation is overwhelmed and the optic nerve becomes hypoxic. A disturbance in oxidative metabolism in the cytochromes of the optic nerve can be seen...... at similar levels of perfusion pressure. The levels of perfusion pressure that lead to optic nerve hypoxia in the laboratory correspond remarkably well to the levels that increase the risk of glaucomatous optic nerve atrophy in human glaucoma patients. The risk for progressive optic nerve atrophy in human...

Fiber optics in adverse environments

International Nuclear Information System (INIS)

Lyous, P.B.

1982-01-01

Radiation effects in optical fibers are considered, taking into account recent progress in the investigation of radiation resistant optical fibers, radiation damage in optical fibers, radiation-induced transient absorption in optical fibers, X-ray-induced transient attenuation at low temperatures in polymer clad silica (PCS) fibers, optical fiber composition and radiation hardness, the response of irradiated optical waveguides at low temperatures, and the effect of ionizing radiation on fiber-optic waveguides. Other topics explored are related to environmental effects on components of fiber optic systems, and radiation detection systems using optical fibers. Fiber optic systems in adverse environments are also discussed, giving attention to the survivability of Army fiber optics systems, space application of fiber optics systems, fiber optic wavelength multiplexing for civil aviation applications, a new fiber optic data bus topology, fiber optics for aircraft engine/inlet control, and application of fiber optics in high voltage substations

Recent progress on laser acceleration research

International Nuclear Information System (INIS)

Nakajima, Kazuhisa; Dewa, Hideki; Hosokai, Tomonao; Kanazawa, Shuhei; Kando, Masaki; Kondoh, Shuji; Kotaki, Hideyuki

2000-01-01

Recently there has been a tremendous experimental progress in ultrahigh field particle acceleration driven by ultraintense laser pulses in plasmas. A design of the laser wakefield accelerators aiming at GeV energy gains is discussed by presenting our recent progress on the laser wakefield acceleration experiments, the developments of high quality electron beam injectors and the capillary plasma waveguide for optical guiding of ultrashort intense laser pulses. (author)

Study on low-cost calibration-free pH sensing with disposable optical sensors

International Nuclear Information System (INIS)

Ge Xudong; Kostov, Yordan; Tolosa, Leah; Rao, Govind

2012-01-01

Highlights: ► Development of disposable calibration-free optical pH sensor. ► Derivation of theoretical calibration model. ► Strategy to eliminate inter-coaster inconsistency. - Abstract: As labor costs become more expensive, less labor-intensive disposable devices have become more ubiquitous. Similarly, the disposable optical pH sensor developed in our lab could provide a convenient yet cost-effective way for pH sensing in processes that require stringent pH control. This optical pH sensor is prepared in uniform individual lots of 100–200 sensors per lot. Calibration is accomplished on a few randomly selected sensors out of each lot. We show that all others in the same lot can then be used directly without requiring individual calibration. In this paper, a calibration model is derived to include all the factors that affect the signal of the disposable sensor. Experimental results show that the derived calibration model fits the experimental data. The readings of 28 randomly selected disposable sensors with 4 sensors from each of the 7 lots show an error less than 0.1 pH units in the useful sensing range of the sensor. The calibration model indicates that if further improvement on precision is desired, more uniform porous material and more advanced coating techniques will be required. When it comes to the effects of the varying coasters, house-made low-cost fluorometers, the variability in the brightness ratio of the blue-to-violet LEDs is the primary reason for the lack of precision. Other factors like LED light intensity distribution, optical properties of the filters and electronics also contribute to the coaster-to-coaster difference, but to a lesser extent. Two different methods for correcting the instrument variations were introduced. After correction, the collective reading errors for all the tested instruments were reduced to less than 0.2 pH units within the sensor's useful sensing range. Based on this result, our lab is currently implementing

Isolated optic nerve pseudotumour

International Nuclear Information System (INIS)

Patankar, T.; Prasad, S.; Krishnan, A.; Laxminarayan, R.

2000-01-01

Isolated optic nerve involvement by the idiopathic inflammatory process is a rare finding and very few reports are available. Here a case of an isolated optic nerve inflammatory pseudotumour presenting with gradually progressive unilateral loss of vision is described. It showed dramatic response to a trial of steroids and its differential diagnoses are discussed. Copyright (1999) Blackwell Science Pty Ltd

Two-dimensional metamaterial optics

International Nuclear Information System (INIS)

Smolyaninov, I I

2010-01-01

While three-dimensional photonic metamaterials are difficult to fabricate, many new concepts and ideas in the metamaterial optics can be realized in two spatial dimensions using planar optics of surface plasmon polaritons. In this paper we review recent progress in this direction. Two-dimensional photonic crystals, hyperbolic metamaterials, and plasmonic focusing devices are demonstrated and used in novel microscopy and waveguiding schemes

Forum metrology 2009: control of optics, targets and optical analyzers

International Nuclear Information System (INIS)

Desenne, D.; Andre, R.

2010-01-01

The 1. 'Forum Metrologie' of the CEA/DAM has been held in the 'Institut Laser et Plasma' on the December 9, 2009, close to the 'Centre d'etudes Scientifiques et Techniques d'Aquitaine'. It has been set up by the 'Departement Lasers de Puissance'. The chosen thematic was the metrology around laser experiments, with a special focus on the metrology of the dedicated optics, targets and optical analysers. The talks have shown the progress and difficulties in each of these fields. (authors)

Nanophotonic Devices for Optical Interconnect

DEFF Research Database (Denmark)

Van Thourhout, D.; Spuesens, T.; Selvaraja, S.K.

2010-01-01

We review recent progress in nanophotonic devices for compact optical interconnect networks. We focus on microdisk-laser-based transmitters and discuss improved design and advanced functionality including all-optical wavelength conversion and flip-flops. Next we discuss the fabrication uniformity...... of the passive routing circuits and their thermal tuning. Finally, we discuss the performance of a wavelength selective detector....

Time Lens based Optical Fourier Transformation for All-Optical Signal Processing of Spectrally-Efficient Data

DEFF Research Database (Denmark)

Guan, Pengyu; Røge, Kasper Meldgaard; Lillieholm, Mads

2017-01-01

We review recent progress in the use of time lens based optical Fourier transformation for advanced all-optical signal processing. A novel time lens based complete optical Fourier transformation (OFT) technique is introduced. This complete OFT is based on two quadratic phase-modulation stages using...... four-wave mixing (FWM), separated by a dispersive medium, which enables time-to-frequency and frequency-to-time conversions simultaneously, thus performing an exchange between the temporal and spectral profiles of the input signal. Using the proposed complete OFT, several advanced all-optical signal......, such as orthogonal frequency division multiplexing (OFDM), Nyquist wavelength-division multiplexing (Nyquist-WDM) and Nyquist optical time division multiplexing (Nyquist-OTDM) signals....

Technical Progress of the New Worlds Observer Mission

Science.gov (United States)

Lo, Amy; Noecker, C.; Cash, W.; NWO Study Team

2009-01-01

We report on the technical progress of the New Worlds Observer (NWO) mission concept. NWO is a two spacecraft mission that is capable of detecting and characterizing extra-solar, terrestrial planets and planetary systems. NWO consists of an external starshade and an UV-optical space telescope, flying in tandem. The starshade is a petal-shaped, opaque screen that creates an extremely dark shadow large enough to shade the telescope aperture from the target star. The NWO team has been addressing the top technology challenges of the concept, and report here our progress. We will present the current mission configuration best suited to address Terrestrial Planet Finding requirements, and highlight the technological breakthroughs that we have achieved this year. In particular, we will report on progress made in precision deployables for the large starshade, and the trajectory & alignment control system for NWO. We will also briefly highlight advances in understanding the starshade optical performance.

Evolution of optic nerve and retina alterations in a child with indirect traumatic neuropathy as assessed by optical coherence tomography

Directory of Open Access Journals (Sweden)

Julia Dutra Rossetto

Full Text Available ABSTRACT Herein, we describe the case of a 4-year-old child with indirect traumatic optic neuropathy and serial changes of the optic nerve head and retinal nerve fiber layer (RNFL documented using optical coherence tomography (OCT. Visual acuity improved despite progressive RNFL thinning and optic disc pallor. We concluded that OCT may be useful for monitoring axonal loss but may not predict the final visual outcome.

Quantum optics

International Nuclear Information System (INIS)

Flytzanis, C.

1988-01-01

The 1988 progress report of the Quantum Optics laboratory (Polytechnic School, France) is presented. The research program is focused on the behavior of dense and dilute materials submitted to short and high-intensity light radiation fields. Nonlinear optics techniques, with time and spatial resolution, are developed. An important research activity concerns the investigations on the interactions between the photon beams and the inhomogeneous or composite materials, as well as the artificial microstructures. In the processes involving molecular beams and surfaces, the research works on the photophysics of surfaces and the molecule-surface interactions, are included [fr

Isolated Optic Disc Tuberculosis

Science.gov (United States)

Mansour, Ahmad M.; Tabbara, Khalid F.; Tabbarah, Zuhair

2015-01-01

We present a healthy male subject who developed progressive visual loss in the left eye initially diagnosed as optic neuritis. Upon suspicion of infectious etiology, testing was positive for tuberculosis. There were no signs or symptoms of active systemic tuberculosis infection. The patient responded swiftly to antimycobacterial therapy with return of vision and resolution of disc swelling. Positive purified protein derivative skin test, negative chest radiograph, negative systemic workup, negative workup for other causes of unilateral optic neuritis and quick response to mycobacterial therapy reaffirm the entity of isolated optic disc tuberculosis similar to isolated choroidal tuberculosis without systemic manifestation. PMID:26483675

Isolated Optic Disc Tuberculosis

Directory of Open Access Journals (Sweden)

Ahmad M. Mansour

2015-09-01

Full Text Available We present a healthy male subject who developed progressive visual loss in the left eye initially diagnosed as optic neuritis. Upon suspicion of infectious etiology, testing was positive for tuberculosis. There were no signs or symptoms of active systemic tuberculosis infection. The patient responded swiftly to antimycobacterial therapy with return of vision and resolution of disc swelling. Positive purified protein derivative skin test, negative chest radiograph, negative systemic workup, negative workup for other causes of unilateral optic neuritis and quick response to mycobacterial therapy reaffirm the entity of isolated optic disc tuberculosis similar to isolated choroidal tuberculosis without systemic manifestation.

Progress of Terahertz Devices Based on Graphene

Institute of Scientific and Technical Information of China (English)

Mai-Xia Fu; Yan Zhang

2013-01-01

Graphene is a one-atom-thick planar sheet of sp2-hybridized orbital bonded honeycomb carbon crystal. Its gapless and linear energy spectra of electrons and holes lead to the unique carrier transport and optical properties, such as giant carrier mobility and broadband flat optical response. As a novel material, graphene has been regarded to be extremely suitable and competent for the development of terahertz (THz) optical devices. In this paper, the fundamental electronic and optic properties of graphene are described. Based on the energy band structure and light transmittance properties of graphene, many novel graphene based THz devices have been proposed, including modulator, generator, detector, and imaging device. This progress has been reviewed. Future research directions of the graphene devices for THz applications are also proposed.

Time lens based optical fourier transformation for advanced processing of spectrally-efficient OFDM and N-WDM signals

DEFF Research Database (Denmark)

Guan, Pengyu; Røge, Kasper Meldgaard; Morioka, Toshio

2016-01-01

We review recent progress in the use of time lens based optical Fourier transformation for advanced optical signal processing, with focus on all-optical generation, detection and format conversion of spectrally-efficient OFDM and N-WDM signals.......We review recent progress in the use of time lens based optical Fourier transformation for advanced optical signal processing, with focus on all-optical generation, detection and format conversion of spectrally-efficient OFDM and N-WDM signals....

Light fidelity (Li-Fi): towards all-optical networking

Science.gov (United States)

Tsonev, Dobroslav; Videv, Stefan; Haas, Harald

2013-12-01

Motivated by the looming radio frequency (RF) spectrum crisis, this paper aims at demonstrating that optical wireless communication (OWC) has now reached a state where it can demonstrate that it is a viable and matured solution to this fundamental problem. In particular, for indoor communications where most mobile data traffic is consumed, light fidelity (Li-Fi) which is related to visible light communication (VLC) offers many key advantages, and effective solutions to the issues that have been posed in the last decade. This paper discusses all key component technologies required to realize optical cellular communication systems referred to here as optical attocell networks. Optical attocells are the next step in the progression towards ever smaller cells, a progression which is known to be the most significant contributor to the improvements in network spectral efficiencies in RF wireless networks.

Progress in miniaturization of a multichannel optical fiber Bragg grating sensor interrogator

Science.gov (United States)

Lopatin, Craig M.; Mahmood, Shah; Mendoza, Edgar; Moslehi, Behzad; Black, Richard; Chau, Kelvin; Oblea, Levy

2007-07-01

An effort to develop a miniaturized multichannel optical fiber Bragg grating sensor interrogator was initiated in 2006 under the Small Business Innovative Research (SBIR) program. The goal was to develop an interrogator that would be sufficiently small and light to be incorporated into a health monitoring system for use on tactical missiles. Two companies, Intelligent Fiber Optic Systems Corporation (IFOS) and Redondo Optics, were funded in Phase I, and this paper describes the prototype interrogators that were developed. The two companies took very different approaches: IFOS focused on developing a unit that would have a high channel count and high resolution, using off-the-shelf components, while Redondo Optics chose to develop a unit that would be very small and lightweight, using custom designed integrated optical chips. It is believed that both approaches will result in interrogators that will be significantly small, lighter, and possibly even more precise than what is currently commercially available. This paper will also briefly describe some of the sensing concepts that may be used to interrogate the health of the solid rocket motors used in many missile systems. The sponsor of this program was NAVAIR PMA 280.

Recent progress in self-assembled quantum-dot optical devices for optical telecommunication: temperature-insensitive 10 Gb s-1 directly modulated lasers and 40 Gb s-1 signal-regenerative amplifiers

International Nuclear Information System (INIS)

Sugawara, M; Hatori, N; Ishida, M; Ebe, H; Arakawa, Y; Akiyama, T; Otsubo, K; Yamamoto, T; Nakata, Y

2005-01-01

This paper presents recent progress in the field of semiconductor lasers and optical amplifiers with InAs-based self-assembled quantum dots in the active region for optical telecommunication. Based on our design in terms of the maximum bandwidth for high-speed modulation and p-type doping in quantum dots for high temperature stability, we realized temperature-insensitive 10 Gb s -1 laser diodes on a GaAs substrate at 1.3 μm. The output waveform at 10 Gb s -1 maintained a clear eye opening, average output power and extinction ratio without current adjustments from 20 deg. C to 70 deg. C. We developed ultrawide-band high-power amplifiers in the 1.5 μm wavelength region on an InP substrate. The amplifier showed ultrafast gain response under gain saturation, and enabled signal regeneration at 40 Gb s -1 by suppressing the '1'-level noise due to the beating between the signal and amplified spontaneous emission. We present our amplifier module with polarization diversity to enable a stable polarization-insensitive performance, and also, discuss prospects for polarization-insensitive quantum dots by the close stacking technique

Optical Coherence Tomography of the Aging Kidney.

Science.gov (United States)

Andrews, Peter M; Wang, Hsing-Wen; Guo, Hengchang; Anderson, Erik; Falola, Reuben; Chen, Yu

2016-12-01

The aging kidney exhibits a progressive decline in renal function with characteristic histopathologic changes and is a risk factor for renal transplant. However, the degree to which the kidney exhibits this decline depends on several factors that vary from one individual to the next. Optical coherence tomography is an evolving noninvasive imaging technology that has recently been used to evaluate acute tubular necrosis of living-human donor kidneys before their transplant. With the increasing use of kidneys from older individuals, it is important to determine whether optical coherence tomography also can distinguish the histopathology associated with aging. In this investigation, we used Munich-Wistar rats to evaluate the ability of optical coherence tomography to detect histopathologic changes associated with aging. Optical coherence tomography observations were correlated with renal function and conventional light microscopic evaluation of these same kidneys. With the onset of severe proteinuria at 10 to 12 months of age, optical coherence tomography revealed tubular necrosis/atrophy, interstitial fibrosis, tubular dilation, and glomerulosclerosis. With a further deterioration in kidney function at 16 to 18 months of age (as indicated by rising creatinine levels), optical coherence tomography revealed more extensive interstitial fibrosis and tubular atrophy, increased tubular dilation with cyst formation and more sclerotic glomeruli. The foregoing observations suggest that optical coherence tomography can be used to detect the histopathology of progressive nephropathy associated with aging.

Strongly interacting fermion systems. Progress report, November 15, 1994--November 14, 1995

International Nuclear Information System (INIS)

1994-01-01

This paper is the progress report for the period November 15, 1993 to November 14, 1994 for a program which relates to studies of strongly interacting fermion systems. The author has made significant progress in three areas, which are discussed in the report. These are: (1) optical properties in the open-quotes electronic structure program,close quotes calculating optical properties of quartz and urea; (2) quasi-one-dimensional systems, discussing the tuning of the large-density-wave or Peierls distortion in transition-metal linear chain compounds and the universal subgap optical absorptance of classes of quasi-one-dimensional compounds; and (3) other strongly interaction fermion systems, emphasizing the study of the effect of many-body interactions on the low-temperature properties of metals and superconductors

Optical Angular Momentum

International Nuclear Information System (INIS)

Arimondo, Ennio

2004-01-01

For many years the Institute of Physics has published books on hot topics based on a collection of reprints from different journals, including some remarks by the editors of each volume. The book on Optical Angular Momentum, edited by L Allen, S M Barnett and M J Padgett, is a recent addition to the series. It reproduces forty four papers originally published in different journals and in a few cases it provides direct access to works not easily accessible to a web navigator. The collection covers nearly a hundred years of progress in physics, starting from an historic 1909 paper by Poynting, and ending with a 2002 paper by Padgett, Barnett and coworkers on the measurement of the orbital angular momentum of a single photon. The field of optical angular momentum has expanded greatly, creating an interdisciplinary attraction for researchers operating in quantum optics, atomic physics, solid state physics, biophysics and quantum information theory. The development of laser optics, especially the control of single mode sources, has made possible the specific design of optical radiation modes with a high degree of control on the light angular momentum. The editors of this book are important figures in the field of angular momentum, having contributed to key progress in the area. L Allen published an historical paper in 1999, he and M J Padgett (together with M Babiker) produced few years ago a long review article which is today still the most complete basic introduction to the angular momentum of light, while S M Barnett has contributed several high quality papers to the progress of this area of physics. The editors' choice provides an excellent overview to all readers, with papers classified into eight different topics, covering the basic principles of the light and spin and orbital angular momentum, the laboratory tools for creating laser beams carrying orbital angular momentum, the optical forces and torques created by laser beams carrying angular momentum on

Beta-Zone parapapillary atrophy and the velocity of glaucoma progression.

Science.gov (United States)

Teng, Christopher C; De Moraes, Carlos Gustavo V; Prata, Tiago S; Tello, Celso; Ritch, Robert; Liebmann, Jeffrey M

2010-05-01

Beta-Zone parapapillary atrophy (PPA) occurs more commonly in eyes with glaucoma. Rates of glaucomatous visual field (VF) progression in eyes with and without beta-zone PPA at the time of baseline assessment were compared. Retrospective, comparative study. Two hundred forty-five patients from the New York Glaucoma Progression Study. Subjects with glaucomatous optic neuropathy and repeatable VF loss were assessed for eligibility. Eyes with a Heidelberg Retina Tomograph II (HRT) examination, at least 5 visual field tests after the HRT in either eye, optic disc photographs, and Zone PPA was defined as a region of chorioretinal atrophy with visible sclera and choroidal vessels adjacent to the optic disc. Global rates of VF progression were determined by automated pointwise linear regression analysis. Univariate analysis included age, gender, ethnicity, central corneal thickness (CCT), refractive error, baseline mean deviation, baseline intraocular pressure (IOP), mean IOP, IOP fluctuation, disc area, rim area, rim area-to-disc area ratio, beta-zone PPA area, beta-zone PPA area-to-disc area ratio, and presence or absence of beta-zone PPA. The relationship between beta-zone PPA and the rate and risk of glaucoma progression. Two hundred forty-five eyes of 245 patients (mean age, 69.6+/-12.3 years) were enrolled. The mean follow-up was 4.9+/-1.4 years and the mean number of VFs after HRT was 9.3+/-2.7. beta-Zone PPA was present in 146 eyes (65%). Eyes with beta-zone PPA progressed more rapidly (-0.84+/-0.8 dB/year) than eyes without it (-0.51+/-0.6 dB/year; Pzone PPA (HR, 2.59; P1.5 dB/year; P = 0.08) global rates of progression occurred more commonly in eyes with beta-zone PPA than in eyes without it. Thinner CCT (zone PPA (kappa = 0.13). Eyes with beta-zone PPA are at increased risk for glaucoma progression and warrant close clinical surveillance. Copyright 2010 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

Optical detection in microfluidic systems

DEFF Research Database (Denmark)

Mogensen, Klaus Bo; Kutter, Jörg Peter

2009-01-01

Optical detection schemes continue to be favoured for measurements in microfluidic systems. A selection of the latest progress mainly within the last two years is critically reviewed. Emphasis is on integrated solutions, such as planar waveguides, coupling schemes to the outside world, evanescent...... to ease commercialisation of the devices. This work will hopefully result in more commercial products that benefit from integrated optics, because the impact on commercial devices so far has been modest....

Digital processing optical transmission and coherent receiving techniques

CERN Document Server

Binh, Le Nguyen

2013-01-01

With coherent mixing in the optical domain and processing in the digital domain, advanced receiving techniques employing ultra-high speed sampling rates have progressed tremendously over the last few years. These advances have brought coherent reception systems for lightwave-carried information to the next stage, resulting in ultra-high capacity global internetworking. Digital Processing: Optical Transmission and Coherent Receiving Techniques describes modern coherent receiving techniques for optical transmission and aspects of modern digital optical communications in the most basic lines. The

X-ray optics developments at ESA

DEFF Research Database (Denmark)

Bavdaz, M.; Wille, E.; Wallace, K.

2013-01-01

Future high energy astrophysics missions will require high performance novel X-ray optics to explore the Universe beyond the limits of the currently operating Chandra and Newton observatories. Innovative optics technologies are therefore being developed and matured by the European Space Agency (ESA......) in collaboration with research institutions and industry, enabling leading-edge future science missions. Silicon Pore Optics (SPO) [1 to 21] and Slumped Glass Optics (SGO) [22 to 29] are lightweight high performance X-ray optics technologies being developed in Europe, driven by applications in observatory class...... reflective coatings [30 to 35]. In addition, the progress with the X-ray test facilities and associated beam-lines is discussed [36]. © (2013) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only....

Dominant optic atrophy

Directory of Open Access Journals (Sweden)

Lenaers Guy

2012-07-01

Full Text Available Abstract Definition of the disease Dominant Optic Atrophy (DOA is a neuro-ophthalmic condition characterized by a bilateral degeneration of the optic nerves, causing insidious visual loss, typically starting during the first decade of life. The disease affects primary the retinal ganglion cells (RGC and their axons forming the optic nerve, which transfer the visual information from the photoreceptors to the lateral geniculus in the brain. Epidemiology The prevalence of the disease varies from 1/10000 in Denmark due to a founder effect, to 1/30000 in the rest of the world. Clinical description DOA patients usually suffer of moderate visual loss, associated with central or paracentral visual field deficits and color vision defects. The severity of the disease is highly variable, the visual acuity ranging from normal to legal blindness. The ophthalmic examination discloses on fundoscopy isolated optic disc pallor or atrophy, related to the RGC death. About 20% of DOA patients harbour extraocular multi-systemic features, including neurosensory hearing loss, or less commonly chronic progressive external ophthalmoplegia, myopathy, peripheral neuropathy, multiple sclerosis-like illness, spastic paraplegia or cataracts. Aetiology Two genes (OPA1, OPA3 encoding inner mitochondrial membrane proteins and three loci (OPA4, OPA5, OPA8 are currently known for DOA. Additional loci and genes (OPA2, OPA6 and OPA7 are responsible for X-linked or recessive optic atrophy. All OPA genes yet identified encode mitochondrial proteins embedded in the inner membrane and ubiquitously expressed, as are the proteins mutated in the Leber Hereditary Optic Neuropathy. OPA1 mutations affect mitochondrial fusion, energy metabolism, control of apoptosis, calcium clearance and maintenance of mitochondrial genome integrity. OPA3 mutations only affect the energy metabolism and the control of apoptosis. Diagnosis Patients are usually diagnosed during their early childhood, because of

Progress towards localization in the attractive Hubbard model

Science.gov (United States)

Morong, W.; Xu, W.; Demarco, B.

2017-04-01

The interplay between fermionic superfluidity and disorder is a topic of long-standing interest that has recently come within reach of ultracold gas experiments. Outstanding questions include the fate of Cooper pairs in a localized superfluid and the effect of disorder on the superfluid transition temperature. We report progress on tackling this problem using a realization of the Hubbard model with attractive interactions. Our system consists of two spin states of fermionic potassium-40 trapped in a cubic optical lattice. Disorder is introduced using an optical speckle potential, and interactions are controlled via a Feshbach resonance. We study the binding and unbinding of Cooper pairs in this system using rf spectroscopy, changes in Tc by measuring the condensate fraction, and transport properties by observing the response to an applied impulse. We will discuss progress towards these measurements.

Optical observations of binary X-ray sources

International Nuclear Information System (INIS)

Boynton, P.E.

1975-01-01

The contribution to the recent progress in astronomy made by optical observations is pointed out. The optical properties of X-ray sources help to establish the physical nature of these objects. The current observational evidence on the binary X-ray sources HZ Her/Her X-1 and HDE 226868/Cyg X-1 is reported. (P.J.S.)

Confocal fluorometer for diffusion tracking in 3D engineered tissue constructs

Science.gov (United States)

Daly, D.; Zilioli, A.; Tan, N.; Buttenschoen, K.; Chikkanna, B.; Reynolds, J.; Marsden, B.; Hughes, C.

2016-03-01

We present results of the development of a non-contacting instrument, called fScan, based on scanning confocal fluorometry for assessing the diffusion of materials through a tissue matrix. There are many areas in healthcare diagnostics and screening where it is now widely accepted that the need for new quantitative monitoring technologies is a major pinch point in patient diagnostics and in vitro testing. With the increasing need to interpret 3D responses this commonly involves the need to track the diffusion of compounds, pharma-active species and cells through a 3D matrix of tissue. Methods are available but to support the advances that are currently only promised, this monitoring needs to be real-time, non-invasive, and economical. At the moment commercial meters tend to be invasive and usually require a sample of the medium to be removed and processed prior to testing. This methodology clearly has a number of significant disadvantages. fScan combines a fiber based optical arrangement with a compact, free space optical front end that has been integrated so that the sample's diffusion can be measured without interference. This architecture is particularly important due to the "wet" nature of the samples. fScan is designed to measure constructs located within standard well plates and a 2-D motion stage locates the required sample with respect to the measurement system. Results are presented that show how the meter has been used to evaluate movements of samples through collagen constructs in situ without disturbing their kinetic characteristics. These kinetics were little understood prior to these measurements.

The ATHENA telescope and optics status

Science.gov (United States)

Bavdaz, Marcos; Wille, Eric; Ayre, Mark; Ferreira, Ivo; Shortt, Brian; Fransen, Sebastiaan; Collon, Maximilien; Vacanti, Giuseppe; Barriere, Nicolas; Landgraf, Boris; Haneveld, Jeroen; van Baren, Coen; Zuknik, Karl-Heintz; Della Monica Ferreira, Desiree; Massahi, Sonny; Christensen, Finn; Krumrey, Michael; Burwitz, Vadim; Pareschi, Giovanni; Spiga, Daniele; Valsecchi, Giuseppe; Vernani, Dervis; Oliver, Paul; Seidel, André

2017-08-01

The work on the definition and technological preparation of the ATHENA (Advanced Telescope for High ENergy Astrophysics) mission continues to progress. In parallel to the study of the accommodation of the telescope, many aspects of the X-ray optics are being evolved further. The optics technology chosen for ATHENA is the Silicon Pore Optics (SPO), which hinges on technology spin-in from the semiconductor industry, and uses a modular approach to produce large effective area lightweight telescope optics with a good angular resolution. Both system studies and the technology developments are guided by ESA and implemented in industry, with participation of institutional partners. In this paper an overview of the current status of the telescope optics accommodation and technology development activities is provided.

Progress in Y-00 physical cipher for Giga bit/sec optical data communications (intensity modulation method)

Science.gov (United States)

Hirota, Osamu; Futami, Fumio

2014-10-01

To guarantee a security of Cloud Computing System is urgent problem. Although there are several threats in a security problem, the most serious problem is cyber attack against an optical fiber transmission among data centers. In such a network, an encryption scheme on Layer 1(physical layer) with an ultimately strong security, a small delay, and a very high speed should be employed, because a basic optical link is operated at 10 Gbit/sec/wavelength. We have developed a quantum noise randomied stream cipher so called Yuen- 2000 encryption scheme (Y-00) during a decade. This type of cipher is a completely new type random cipher in which ciphertext for a legitimate receiver and eavesdropper are different. This is a condition to break the Shannon limit in theory of cryptography. In addition, this scheme has a good balance on a security, a speed and a cost performance. To realize such an encryption, several modulation methods are candidates such as phase-modulation, intensity-modulation, quadrature amplitude modulation, and so on. Northwestern university group demonstrated a phase modulation system (α=η) in 2003. In 2005, we reported a demonstration of 1 Gbit/sec system based on intensity modulation scheme(ISK-Y00), and gave a design method for quadratic amplitude modulation (QAM-Y00) in 2005 and 2010. An intensity modulation scheme promises a real application to a secure fiber communication of current data centers. This paper presents a progress in quantum noise randomized stream cipher based on ISK-Y00, integrating our theoretical and experimental achievements in the past and recent 100 Gbit/sec(10Gbit/sec × 10 wavelengths) experiment.

Acute optic neuropathy associated with a novel MFN2 mutation.

Science.gov (United States)

Leonardi, Luca; Marcotulli, Christian; Storti, Eugenia; Tessa, Alessandra; Serrao, Mariano; Parisi, Vincenzo; Santorelli, F M; Pierelli, Francesco; Casali, Carlo

2015-07-01

Mutations in the mitofusin 2 (MFN2) gene cause CMT2A the most common form of autosomal dominant axonal Charcot-Marie-Tooth (CMT). In addition, mutations in MFN2 have been shown to be responsible for Hereditary Motor Sensory Neuropathy type VI (HSMN VI), a rare early-onset axonal CMT associated with optic neuropathy. Most reports of HMSN VI presented with a sub-acute form of optic neuropathy. Herein, we report a CMT2A patient, who developed very rapidly progressing severe optic neuropathy. A 40-year-old Caucasian man was evaluated for gait disturbance and lower limbs weakness, slowly progressed over the last 2 years. Due to clinical data and family history, a diagnosis of CMT2 was made. The novel heterozygous c.775C > T (p.Arg259Cys) mutation in MFN2 was detected in the patient and his clinical affected mother. Interestingly, the patient developed a severe sudden bilateral visual deterioration few years early, with clinical and instrumental picture suggestive of acute bilateral optic neuropathy. Our report expands the spectrum of MFN2-related manifestation because it indicates that visual symptoms of HMSN VI may enter in the differential with acquired or hereditary acute optic neuropathies, and that severe optic neuropathy is not invariably an early manifestation of the disease but may occur as disease progressed. This report could have an impact on clinicians who evaluate patients with otherwise unexplainable bilateral acute-onset optic neuropathy, especially if associated with a motor and sensory axonal neuropathy.

Inspection methods progression of diabetic optic neuropathy

Directory of Open Access Journals (Sweden)

Yan Sun

2015-06-01

Full Text Available Increasing incidence of diabetes, diet restructuring with excessive intake of high-calorie foods closely related with this. Currently diabetes prevalence rate increased from 7% in 2003 to 14% in 2010. Diabetes can cause a variety of eye diseases, such as corneal ulcers, glaucoma, vitreous hemorrhage and so on. Diabetic retinopathy and cataract are the most common and greater impact on patients. At present, study for diabetic retinopathy(DRis wider than diabetes optic neuropathy(DON. Clinical manifestations of DON are not specific, but DON occurred extensively, also contributed to an important cause of blindness.In this paper, we collected a variety of inspection and early diagnosis methods, try to achieve early detection, interventional therapy and good treatment for this disease. Here to make a presentation on the various types of inspection methods.

Handbook of nano-optics and nanophotonics

CERN Document Server

2013-01-01

In the 1990s, optical technology and photonics industry developed fast, but further progress became difficult due to a fundamental limit of light known as the diffraction limit. This limit could be overcome using the novel technology of nano-optics or nanophotonics in which the size of the electromagnetic field is decreased down to the nanoscale and is used as a carrier for signal transmission, processing, and fabrication. Such a decrease beyond the diffraction limit is possible by using optical near-fields. The true nature of nano-optics and nanophotonics involves not only their abilities to meet the above requirements but also their abilities to realize qualitative innovations in photonic devices, fabrication techniques, energy conversion and information processing systems. The objective of this work is to review the innovations of optical science and technology by nano-optics and nanophotonics. While in conventional optical science and technology, light and matter are discussed separately, in nano-optics a...

In situ Measurements of Phytoplankton Fluorescence Using Low Cost Electronics

Directory of Open Access Journals (Sweden)

Dana L. Wright

2013-06-01

Full Text Available Chlorophyll a fluorometry has long been used as a method to study phytoplankton in the ocean. In situ fluorometry is used frequently in oceanography to provide depth-resolved estimates of phytoplankton biomass. However, the high price of commercially manufactured in situ fluorometers has made them unavailable to some individuals and institutions. Presented here is an investigation into building an in situ fluorometer using low cost electronics. The goal was to construct an easily reproducible in situ fluorometer from simple and widely available electronic components. The simplicity and modest cost of the sensor makes it valuable to students and professionals alike. Open source sharing of architecture and software will allow students to reconstruct and customize the sensor on a small budget. Research applications that require numerous in situ fluorometers or expendable fluorometers can also benefit from this study. The sensor costs US$150.00 and can be constructed with little to no previous experience. The sensor uses a blue LED to excite chlorophyll a and measures fluorescence using a silicon photodiode. The sensor is controlled by an Arduino microcontroller that also serves as a data logger.

Compact super-wideband optical antenna

Science.gov (United States)

Wang, Wen C.; Forber, Richard; Bui, Kenneth

2009-05-01

We present progress on advanced optical antennas, which are compact, small size-weight-power units capable to receive super wideband radiated RF signals from 30 MHz to over 3 GHz. Based on electro-optical modulation of fiber-coupled guided wave light, these dielectric E-field sensors exhibit dipole-like azimuthal omni directionality, and combine small size (channels, and high EO sensing materials. The antenna system photonic link consists of a 1550 nm PM fiber-pigtailed laser, a specialized optical modulator antenna in channel waveguide format, a wideband photoreceiver, and optical phase stabilizing components. The optical modulator antenna design employs a dielectric (no electrode) Mach-Zehnder interferometer (MZI) arranged so that sensing RF bandwidth is not limited by optical transit time effects, and MZI phase drift is bias stabilized. For a prototype optical antenna system that is < 100 in3, < 10 W, < 5 lbs, we present test data on sensitivity (< 20 mV/m-Hz1/2), RF bandwidth, and antenna directionality, and show good agreement with theoretical predictions.

Structural characteristics of the acquired optic disc pit and the rate of progressive retinal nerve fiber layer thinning in primary open-angle glaucoma.

Science.gov (United States)

Lee, Seung Hyen; Lee, Eun Ji; Kim, Tae-Woo

2015-10-01

The optic disc pit (ODP) has been considered a region of localized susceptibility to the damage of glaucoma. To determine whether the rate of retinal nerve fiber layer (RNFL) thinning differs according to the presence and structural characteristics of an ODP in primary open-angle glaucoma. We performed a prospective case-control study that included 163 eyes with primary open-angle glaucoma (83 with an ODP and 80 without an ODP) from Glaucoma Clinic of Seoul National University Bundang Hospital. Participants were enrolled from the ongoing Investigating Glaucoma Progression Study from January 1, 2012, through May 31, 2014. Mean (SD) follow-up was 3.32 (0.49) years (through May 31, 2014). Optic nerve heads underwent swept-source optical coherence tomography (OCT) to determine the presence of focal lamina cribrosa alteration and its structural characteristics. Eyes with and without photographic ODPs and corresponding microscopic laminar alterations were assigned to the ODP and non-ODP groups, respectively. The rates of progressive thinning of global and 6 sectoral spectral-domain OCT RNFL thicknesses were determined by linear regression and compared between the 2 groups. We used a general linear model to determine the factors associated with the rate of RNFL thinning; data obtained from September 21, 2009, through May 31, 2014, were used to calculate the rate of RNFL thinning. The relationship between the presence and structural characteristics of ODPs and the rate of progressive OCT RNFL thinning. Thinning of the RNFL was faster in the ODP group than in the non-ODP group in the global (mean [SD], -1.44 [1.31] vs -0.93 [1.10] [95% CI, -0.97 to -0.19] μm/y; P = .008), temporoinferior (mean [SD], -4.17 [4.15] vs -1.97 [3.26] [95% CI, -3.36 to -1.04] μm/y; P < .001), and temporal (mean [SD], -1.92 [2.62] vs -0.89 [1.62] [95% CI, -1.70 to -0.35] μm/y; P = .003) sectors. The rate of RNFL thinning was maximum in the temporoinferior sector (mean [SD], -4

Optics and Fluid Dynamics Department. Annual progress report 1 January - 31 December 1990

International Nuclear Information System (INIS)

Juul Rasmussen, J.; Hanson, S.G.

1991-02-01

Research in the Optics and Fluid Dynamics Department covers plasma physics, fluid dynamics, optics, and neural networks. Plasma physics is concentrated on basic investigations with relevance to fusion plasmas. Both theoretical and experimental work has been performed. Pellet injection systems have been developed. Within the area of fluid dynamics spectral models for studying the dynamcis of coherent structures have been developed. Optical diagnostic methods based on quasi-elastic light scattering have been developed. Beam propagation in random and nonlinear media has been investigated. Spatial and temporal processing schemes, especially for pattern recognition, have been investigated. (author)

Non-Hermitian optics in atomic systems

Science.gov (United States)

Zhang, Zhaoyang; Ma, Danmeng; Sheng, Jiteng; Zhang, Yiqi; Zhang, Yanpeng; Xiao, Min

2018-04-01

A wide class of non-Hermitian Hamiltonians can possess entirely real eigenvalues when they have parity-time (PT) symmetric potentials. Recently, this family of non-Hermitian systems has attracted considerable attention in diverse areas of physics due to their extraordinary properties, especially in optical systems based on solid-state materials, such as coupled gain-loss waveguides and microcavities. Considering the desired refractive index can be effectively manipulated through atomic coherence, it is important to realize such non-Hermitian optical potentials and further investigate their distinct properties in atomic systems. In this paper, we review the recent theoretical and experimental progress of non-Hermitian optics with coherently prepared multi-level atomic configurations. The realizations of (anti-) PT symmetry with different schemes have extensively demonstrated the special optical properties of non-Hermitian optical systems with atomic coherence.

PREVAIL: latest electron optics results

Science.gov (United States)

Pfeiffer, Hans C.; Golladay, Steven D.; Gordon, Michael S.; Kendall, Rodney A.; Lieberman, Jon E.; Rockrohr, James D.; Stickel, Werner; Yamaguchi, Takeshi; Okamoto, Kazuya; Umemoto, Takaaki; Shimizu, Hiroyasu; Kojima, Shinichi; Hamashima, Muneki

2002-07-01

The PREVAIL electron optics subsystem developed by IBM has been installed at Nikon's facility in Kumagaya, Japan, for integration into the Nikon commercial EPL stepper. The cornerstone of the electron optics design is the Curvilinear Variable Axis Lens (CVAL) technique originally demonstrated with a proof of concept system. This paper presents the latest experimental results obtained with the electron optical subsystem at Nikon's facility. The results include micrographs illustrating proper CVAL operation through the spatial resolution achieved over the entire optical field of view. They also include data on the most critical issue of the EPL exposure approach: subfield stitching. The methodology of distortion correction will be described and both micrographs and metrology data of stitched subfields will be presented. This paper represents a progress report of the IBM/Nikon alliance activity on EPL.

Management of optic pathway and chiasmatic-hypothalamic gliomas in children with radiation therapy

International Nuclear Information System (INIS)

Erkal, Haldun Suekrue; Serin, Meltem; Cakmak, Ahmet

1997-01-01

Background and purpose: Optic pathway and chiasmatic-hypothalamic gliomas are rare childhood tumors. This study presents the experience in management of these tumors with radiation therapy. Materials and methods: Thirty-three children with the diagnosis of optic pathway and chiasmatic-hypothalamic gliomas were treated with radiation therapy from 1973 through 1994 in the Department of Radiation Oncology at Ankara University Faculty of Medicine. Twenty-four children had optic pathway gliomas and nine had chiasmatic-hypothalamic gliomas. Evidence of neurofibromatosis was present in six children. Subtotal resection was performed in 22 children and a biopsy in seven. The most common prescription for total tumor dose was 50 Gy, delivered in 2 Gy daily fractions. Follow-up ranged from 0.5 to 16.1 years (mean, 13.6 years). Results: Overall, progression-free and cause-specific survival probabilities for the entire group were 93%, 82% and 93%, respectively, at 5 years and 79%, 77% and 88%, respectively, at 10 years. Differences in overall, progression-free and cause-specific survival probabilities between optic pathway and chiasmatic-hypothalamic gliomas were not statistically significant. Absence of evidence of neurofibromatosis correlated with significantly better progression-free and cause-specific survival probabilities. Conclusion: Radiation therapy is effective in stabilization or improvement of vision and prevention of tumor progression in both optic pathway and chiasmatic-hypothalamic gliomas

Progress in nanophotonics 1

CERN Document Server

Ohtsu, Motoichi

2011-01-01

This book focuses on the recent progress in nanophotonics technology to be used to develop novel nano-optical devices, fabrication technology, and security systems. It begins with a review of the concept of dressed photons and applications to devices, fabrication, and systems; principles and applications. Further topics include: DNA process for quantum dot chain, photon enhanced emission microscopy, near field spectroscopy of metallic nanostructure, self-organized fabrication of composite semiconductor quantum dots, formation of metallic nanostructure, and nanophotonic information systems with

Multimodal imaging of central retinal disease progression in a 2 year mean follow up of Retinitis Pigmentosa

Science.gov (United States)

Sujirakul, Tharikarn; Lin, Michael K.; Duong, Jimmy; Wei, Ying; Lopez-Pintado, Sara; Tsang, Stephen H.

2015-01-01

Purpose To determine the rate of progression and optimal follow up time in patients with advanced stage retinitis pigmentosa (RP) comparing the use of fundus autofluorescence imaging and spectral domain optical coherence tomography. Design Retrospective analysis of progression rate. Methods Longitudinal imaging follow up in 71 patients with retinitis pigmentosa was studied using the main outcome measurements of hyperautofluoresent ring horizontal diameter and vertical diameter along with ellipsoid zone line width from spectral domain optical coherence tomography. Test-retest reliability and the rate of progression were calculated. The interaction between the progression rates was tested for sex, age, mode of inheritance, and baseline measurement size. Symmetry of left and right eye progression rate was also tested. Results Significant progression was observed in >75% of patients during the 2 year mean follow up. The mean annual progression rates of ellipsoid zone line, and hyperautofluorescent ring horizontal diameter and vertical diameter were 0.45° (4.9%), 0.51° (4.1%), and 0.42° (4.0%), respectively. The e llipsoid zone line width, and hyperautofluorescent ring horizontal diameter and vertical diameter had low test-retest variabilities of 8.9%, 9.5% and 9.6%, respectively. This study is the first to demonstrate asymmetrical structural progression rate between right and left eye, which was found in 19% of patients. The rate of progression was significantly slower as the disease approached the fovea, supporting the theory that RP progresses in an exponential fashion. No significant interaction between progression rate and patient age, sex, or mode of inheritance was observed. Conclusions Fundus autofluorescence and optical coherence tomography detect progression in patients with RP reliably and with strong correlation. These parameters may be useful alongside functional assessments as the outcome measurements for future therapeutic trials. Follow-up at 1 year

Current Developments on Optical Feedback Interferometry as an All-Optical Sensor for Biomedical Applications

Science.gov (United States)

Perchoux, Julien; Quotb, Adam; Atashkhooei, Reza; Azcona, Francisco J.; Ramírez-Miquet, Evelio E.; Bernal, Olivier; Jha, Ajit; Luna-Arriaga, Antonio; Yanez, Carlos; Caum, Jesus; Bosch, Thierry; Royo, Santiago

2016-01-01

Optical feedback interferometry (OFI) sensors are experiencing a consistent increase in their applications to biosensing due to their contactless nature, low cost and compactness, features that fit very well with current biophotonics research and market trends. The present paper is a review of the work in progress at UPC-CD6 and LAAS-CNRS related to the application of OFI to different aspects of biosensing, both in vivo and ex vivo. This work is intended to present the variety of opportunities and potential applications related to OFI that are available in the field. The activities presented are divided into two main sensing strategies: The measurement of optical path changes and the monitoring of flows, which correspond to sensing strategies linked to the reconstruction of changes of amplitude from the interferometric signal, and to classical Doppler frequency measurements, respectively. For optical path change measurements, measurements of transient pulses, usual in biosensing, together with the measurement of large displacements applied to designing palliative care instrumentation for Parkinson disease are discussed. Regarding the Doppler-based approach, progress in flow-related signal processing and applications in real-time monitoring of non-steady flows, human blood flow monitoring and OFI pressure myograph sensing will be presented. In all cases, experimental setups are discussed and results presented, showing the versatility of the technique. The described applications show the wide capabilities in biosensing of the OFI sensor, showing it as an enabler of low-cost, all-optical, high accuracy biomedical applications. PMID:27187406

Current Developments on Optical Feedback Interferometry as an All-Optical Sensor for Biomedical Applications

Directory of Open Access Journals (Sweden)

Julien Perchoux

2016-05-01

Full Text Available Optical feedback interferometry (OFI sensors are experiencing a consistent increase in their applications to biosensing due to their contactless nature, low cost and compactness, features that fit very well with current biophotonics research and market trends. The present paper is a review of the work in progress at UPC-CD6 and LAAS-CNRS related to the application of OFI to different aspects of biosensing, both in vivo and ex vivo. This work is intended to present the variety of opportunities and potential applications related to OFI that are available in the field. The activities presented are divided into two main sensing strategies: The measurement of optical path changes and the monitoring of flows, which correspond to sensing strategies linked to the reconstruction of changes of amplitude from the interferometric signal, and to classical Doppler frequency measurements, respectively. For optical path change measurements, measurements of transient pulses, usual in biosensing, together with the measurement of large displacements applied to designing palliative care instrumentation for Parkinson disease are discussed. Regarding the Doppler-based approach, progress in flow-related signal processing and applications in real-time monitoring of non-steady flows, human blood flow monitoring and OFI pressure myograph sensing will be presented. In all cases, experimental setups are discussed and results presented, showing the versatility of the technique. The described applications show the wide capabilities in biosensing of the OFI sensor, showing it as an enabler of low-cost, all-optical, high accuracy biomedical applications.

Macular hole formation, progression, and surgical repair: case series of serial optical coherence tomography and time lapse morphing video study

Science.gov (United States)

2010-01-01

Background To use a new medium to dynamically visualize serial optical coherence tomography (OCT) scans in order to illustrate and elucidate the pathogenesis of idiopathic macular hole formation, progression, and surgical closure. Case Presentations Two patients at the onset of symptoms with early stage macular holes and one patient following repair were followed with serial OCTs. Images centered at the fovea and at the same orientation were digitally exported and morphed into an Audiovisual Interleaving (avi) movie format. Morphing videos from serial OCTs allowed the OCTs to be viewed dynamically. The videos supported anterior-posterior vitreofoveal traction as the initial event in macular hole formation. Progression of the macular hole occurred with increased cystic thickening of the fovea without evidence of further vitreofoveal traction. During cyst formation, the macular hole enlarged as the edges of the hole became elevated from the retinal pigment epithelium (RPE) with an increase in subretinal fluid. Surgical repair of a macular hole revealed initial closure of the macular hole with subsequent reabsorption of the sub-retinal fluid and restoration of the foveal contour. Conclusions Morphing videos from serial OCTs are a useful tool and helped illustrate and support anterior-posterior vitreofoveal traction with subsequent retinal hydration as the pathogenesis of idiopathic macular holes. PMID:20849638

Progress in the Correlative Atomic Force Microscopy and Optical Microscopy

Directory of Open Access Journals (Sweden)

Lulu Zhou

2017-04-01

Full Text Available Atomic force microscopy (AFM has evolved from the originally morphological imaging technique to a powerful and multifunctional technique for manipulating and detecting the interactions between molecules at nanometer resolution. However, AFM cannot provide the precise information of synchronized molecular groups and has many shortcomings in the aspects of determining the mechanism of the interactions and the elaborate structure due to the limitations of the technology, itself, such as non-specificity and low imaging speed. To overcome the technical limitations, it is necessary to combine AFM with other complementary techniques, such as fluorescence microscopy. The combination of several complementary techniques in one instrument has increasingly become a vital approach to investigate the details of the interactions among molecules and molecular dynamics. In this review, we reported the principles of AFM and optical microscopy, such as confocal microscopy and single-molecule localization microscopy, and focused on the development and use of correlative AFM and optical microscopy.

Solar tomography adaptive optics.

Science.gov (United States)

Ren, Deqing; Zhu, Yongtian; Zhang, Xi; Dou, Jiangpei; Zhao, Gang

2014-03-10

Conventional solar adaptive optics uses one deformable mirror (DM) and one guide star for wave-front sensing, which seriously limits high-resolution imaging over a large field of view (FOV). Recent progress toward multiconjugate adaptive optics indicates that atmosphere turbulence induced wave-front distortion at different altitudes can be reconstructed by using multiple guide stars. To maximize the performance over a large FOV, we propose a solar tomography adaptive optics (TAO) system that uses tomographic wave-front information and uses one DM. We show that by fully taking advantage of the knowledge of three-dimensional wave-front distribution, a classical solar adaptive optics with one DM can provide an extra performance gain for high-resolution imaging over a large FOV in the near infrared. The TAO will allow existing one-deformable-mirror solar adaptive optics to deliver better performance over a large FOV for high-resolution magnetic field investigation, where solar activities occur in a two-dimensional field up to 60'', and where the near infrared is superior to the visible in terms of magnetic field sensitivity.

ESA-led ATHENA/IXO optics development status

DEFF Research Database (Denmark)

Bavdaz, Marcos; Rando, Nicola; Wille, Eric

2011-01-01

, under the name of ATHENA (Advanced Telescope for High Energy Astrophysics), with possible participation of NASA and JAXA. The mission is building on the novel Silicon Pore Optics (SPO) technology to achieve the required performance for this demanding astrophysics observatory. This technology is being...... developed by an industrial consortium, and involves also several research institutes [1-12]. A second optics technology, slumped glass optics (SGO), which is being developed in Europe and the USA, was the backup technology for IXO, and additionally work is progressing on improved reflective coatings and X...

Research Progress of Optical Fabrication and Surface-Microstructure Modification of SiC

Directory of Open Access Journals (Sweden)

Fang Jiang

2012-01-01

Full Text Available SiC has become the best candidate material for space mirror and optical devices due to a series of favorable physical and chemical properties. Fine surface optical quality with the surface roughness (RMS less than 1 nm is necessary for fine optical application. However, various defects are present in SiC ceramics, and it is very difficult to polish SiC ceramic matrix with the 1 nm RMS. Surface modification of SiC ceramics must be done on the SiC substrate. Four kinds of surface-modification routes including the hot pressed glass, the C/SiC clapping, SiC clapping, and Si clapping on SiC surface have been reported and reviewed here. The methods of surface modification, the mechanism of preparation, and the disadvantages and advantages are focused on in this paper. In our view, PVD Si is the best choice for surface modification of SiC mirror.

Transferring diffractive optics from research to commercial applications: Part I - progress in the patent landscape

Science.gov (United States)

Brunner, Robert

2013-12-01

In the last 20 years, diffractive optics experienced a strong research interest and was in the center of many development projects in applied optics. To offer a side view for optical engineers, here, we discuss selected, business-related aspects of the current status of the transfer process to bring diffractive optics into commercial products. The contribution is divided into two parts. Here, in part I, we focus on the patent landscape of diffractive optics with a closer look on the temporal development and the distribution over main players. As an important result, currently, new strong patent activities are observed especially in the context of imaging systems. In the second part, the business volumes of selected market segments are discussed.

Diamond x-ray optics: Transparent, resilient, high-resolution, and wavefront preserving

International Nuclear Information System (INIS)

Shvyd’ko, Yuri; Blank, Vladimir; Terentyev, Sergey

2017-01-01

Diamond features a unique combination of outstanding physical properties perfect for numerous x-ray optics applications, where traditional materials such as silicon fail to perform. In the last two decades, impressive progress has been achieved in synthesizing diamond with high crystalline perfection, in manufacturing efficient, resilient, high-resolution, wavefront-preserving diamond optical components, and in implementing them in cutting-edge x-ray instruments. Diamond optics are essential for tailoring x-rays to the most challenging needs of x-ray research. Furthermore, they are becoming vital for the generation of fully coherent hard x-rays by seeded x-ray free-electron lasers. In this article, we review progress in manufacturing flawless diamond crystal components and their applications in diverse x-ray optical devices, such as x-ray monochromators, beam splitters, high-reflectance backscattering mirrors, lenses, phase plates, diffraction gratings, bent-crystal spectrographs, and windows.

Single-session Gamma Knife radiosurgery for optic pathway/hypothalamic gliomas.

Science.gov (United States)

El-Shehaby, Amr M N; Reda, Wael A; Abdel Karim, Khaled M; Emad Eldin, Reem M; Nabeel, Ahmed M

2016-12-01

OBJECTIVE Because of their critical and central location, it is deemed necessary to fractionate when considering irradiating optic pathway/hypothalamic gliomas. Stereotactic fractionated radiotherapy is considered safer when dealing with gliomas in this location. In this study, the safety and efficacy of single-session stereotactic radiosurgery for optic pathway/hypothalamic gliomas were reviewed. METHODS Between December 2004 and June 2014, 22 patients with optic pathway/hypothalamic gliomas were treated by single-session Gamma Knife radiosurgery. Twenty patients were available for follow-up for a minimum of 1 year after treatment. The patients were 5 to 43 years (median 16 years) of age. The tumor volume was 0.15 to 18.2 cm 3 (median 3.1 cm 3 ). The prescription dose ranged from 8 to 14 Gy (median 11.5 Gy). RESULTS The mean follow-up period was 43 months. Five tumors involved the optic nerve only, and 15 tumors involved the chiasm/hypothalamus. Two patients died during the follow-up period. The tumors shrank in 12 cases, remained stable in 6 cases, and progressed in 2 cases, thereby making the tumor control rate 90%. Vision remained stable in 12 cases, improved in 6 cases, and worsened in 2 cases in which there was tumor progression. Progression-free survival was 83% at 3 years. CONCLUSIONS The initial results indicate that single-session Gamma Knife radiosurgery is a safe and effective treatment option for optic pathway/hypothalamic gliomas.

NMR and optical studies of piezoelectric polymers

International Nuclear Information System (INIS)

Schmidt, V.H.; Tuthill, G.F.

1993-01-01

Progress is reported in several areas dealing with piezoelectric (electroactive) polymers (mostly vinylidene fluoride, trifluoroethylene, copolymers, PVF 2 ) and liquid crystals. Optical studies, neutron scattering, NMR, thermal, theory and modeling were done

Recent Progress in Adjustable X-ray Optics for Astronomy

Science.gov (United States)

Reid, Paul B.; Allured, Ryan; Cotroneo, Vincenzo; McMuldroch, Stuart; Marquez, Vanessa; Schwartz, Daniel A.; Vikhlinin, Alexey; ODell, Stephen L.; Ramsey, Brian; Trolier-McKinstry, Susan;

Microcomputer-based real-time optical signal processing system

Science.gov (United States)

Yu, F. T. S.; Cao, M. F.; Ludman, J. E.

1986-01-01

A microcomputer-based real-time programmable optical signal processing system utilizing a Magneto-Optic Spatial Light Modulator (MOSLM) and a Liquid Crystal Light Valve (LCLV) is described. This system can perform a myriad of complicated optical operations, such as image correlation, image subtraction, matrix multiplication and many others. The important assets of this proposed system must be the programmability and the capability of real-time addressing. The design specification and the progress toward practical implementation of this proposed system are discussed. Some preliminary experimental demonstrations are conducted. The feasible applications of this proposed system to image correlation for optical pattern recognition, image subtraction for IC chip inspection and matrix multiplication for optical computing are demonstrated.

NuSTAR Hard X-ray Optics

DEFF Research Database (Denmark)

Koglin, Jason E.; Christensen, Finn Erland; Craig, William W.

2005-01-01

The Nuclear Spectroscopic Telescope Array (NuSTAR) is a small explorer (SMEX) mission currently under an extended Phase A study by NASA. NuSTAR will be the first satellite mission to employ focusing optics in the hard X-ray band (8- 80 keV). Its design eliminates high detector backgrounds, allows...... and production process. We also describe the progress of several components of our independent optics development program that are beginning to reach maturity and could possibly be incorporated into the NuSTAR production scheme. We then present environmental test results that are being conducted in preparation...... of full space qualification of the NuSTAR optics....

Integrated optics theory and technology

CERN Document Server

Hunsperger, Robert G

1984-01-01

Our intent in producing this book was to provide a text that would be comprehensive enough for an introductory course in integrated optics, yet concise enough in its mathematical derivations to be easily readable by a practicing engineer who desires an overview of the field. The response to the first edition has indeed been gratifying; unusually strong demand has caused it to be sold out during the initial year of publication, thus providing us with an early opportunity to produce this updated and improved second edition. This development is fortunate, because integrated optics is a very rapidly progressing field, with significant new research being regularly reported. Hence, a new chapter (Chap. 17) has been added to review recent progress and to provide numerous additional references to the relevant technical literature. Also, thirty-five new problems for practice have been included to supplement those at the ends of chapters in the first edition. Chapters I through 16 are essentially unchanged, except for ...

Optical MEMS for chemical analysis and biomedicine

CERN Document Server

Jiang, Hongrui

2016-01-01

This book describes the current state of optical MEMS in chemical and biomedical analysis and brings together current trends and highlights topics representing the most exciting progress in recent years in the field.

Solar Adaptive Optics

Directory of Open Access Journals (Sweden)

Thomas R. Rimmele

2011-06-01

Full Text Available Adaptive optics (AO has become an indispensable tool at ground-based solar telescopes. AO enables the ground-based observer to overcome the adverse effects of atmospheric seeing and obtain diffraction limited observations. Over the last decade adaptive optics systems have been deployed at major ground-based solar telescopes and revitalized ground-based solar astronomy. The relatively small aperture of solar telescopes and the bright source make solar AO possible for visible wavelengths where the majority of solar observations are still performed. Solar AO systems enable diffraction limited observations of the Sun for a significant fraction of the available observing time at ground-based solar telescopes, which often have a larger aperture than equivalent space based observatories, such as HINODE. New ground breaking scientific results have been achieved with solar adaptive optics and this trend continues. New large aperture telescopes are currently being deployed or are under construction. With the aid of solar AO these telescopes will obtain observations of the highly structured and dynamic solar atmosphere with unprecedented resolution. This paper reviews solar adaptive optics techniques and summarizes the recent progress in the field of solar adaptive optics. An outlook to future solar AO developments, including a discussion of Multi-Conjugate AO (MCAO and Ground-Layer AO (GLAO will be given.

Microwave-optical double resonance spectroscopy. Progress report, February 1, 1975--January 31, 1976

International Nuclear Information System (INIS)

Pratt, D.W.

1975-01-01

Zero-field and high-field optical detection of magnetic resonance (ODMR), electron paramagnetic resonance (EPR), and optical spectroscopy experiments were performed on several systems in order to further basic knowledge of the structure, reactions, and response to radiation of atoms, molecules, and ions. Results on the following studies are reported: the direct observation of level anticrossing and mixing effects in excited molecular triplet states; anomalous zero-field splittings in the lowest triplet state of 1-iodonaphthalene; evidence for second-order spin-orbit coupling and spin delocalization effects in the lowest triplet state of benzophenone; direct observation of the optical absorption spectra of reactive free radicals at room temperature; measurements of the activation and thermodynamic parameters of several cyclohexenyl and cyclohexanonyl radicals; complete analyses of the level anticrossing and cross relaxation spectra of oriented molecular triplet states; solutions to the spin Hamiltonian for S = 1, I = 5/2 systems in both zero-field and high-field, an improvement by a factor of ten in the resolution of ODMR experiments in high field; and measurements of the optical and magnetic resonance properties of a series of halogenated naphthalenes in their lowest triplet states

Glaucoma severity affects diffusion tensor imaging (DTI) parameters of the optic nerve and optic radiation

Energy Technology Data Exchange (ETDEWEB)

Sidek, S. [Department of Biomedical Imaging, University Malaya, Research Imaging Centre, Faculty of Medicine, University Malaya (Malaysia); Medical Imaging Unit, Faculty of Medicine, Universiti Teknologi MARA, Selangor (Malaysia); Ramli, N. [Department of Biomedical Imaging, University Malaya, Research Imaging Centre, Faculty of Medicine, University Malaya (Malaysia); Rahmat, K., E-mail: katt_xr2000@yahoo.com [Department of Biomedical Imaging, University Malaya, Research Imaging Centre, Faculty of Medicine, University Malaya (Malaysia); Ramli, N.M.; Abdulrahman, F. [Department of Ophthalmology, Faculty of Medicine, University Malaya, Kuala Lumpur (Malaysia); Tan, L.K. [Department of Biomedical Imaging, University Malaya, Research Imaging Centre, Faculty of Medicine, University Malaya (Malaysia)

2014-08-15

Objectives: To evaluate whether MR diffusion tensor imaging (DTI) of the optic nerve and optic radiation in glaucoma patients provides parameters to discriminate between mild and severe glaucoma and to determine whether DTI derived indices correlate with retinal nerve fibre layer (RNFL) thickness. Methods: 3-Tesla DTI was performed on 90 subjects (30 normal, 30 mild glaucoma and 30 severe glaucoma subjects) and the FA and MD of the optic nerve and optic radiation were measured. The categorisation into mild and severe glaucoma was done using the Hodapp–Parrish–Anderson (HPA) classification. RNFL thickness was also assessed on all subjects using OCT. Receiver operating characteristic (ROC) analysis and Spearman's correlation coefficient was carried out. Results: FA and MD values in the optic nerve and optic radiation decreased and increased respectively as the disease progressed. FA at the optic nerve had the highest sensitivity (87%) and specificity (80%). FA values displayed the strongest correlation with RNFL thickness in the optic nerve (r = 0.684, p ≤ 0.001) while MD at the optic radiation showed the weakest correlation with RNFL thickness (r = −0.360, p ≤ 0.001). Conclusions: The high sensitivity and specificity of DTI-derived FA values in the optic nerve and the strong correlation between DTI-FA and RNFL thickness suggest that these parameters could serve as indicators of disease severity.

Glaucoma severity affects diffusion tensor imaging (DTI) parameters of the optic nerve and optic radiation

International Nuclear Information System (INIS)

Sidek, S.; Ramli, N.; Rahmat, K.; Ramli, N.M.; Abdulrahman, F.; Tan, L.K.

2014-01-01

Objectives: To evaluate whether MR diffusion tensor imaging (DTI) of the optic nerve and optic radiation in glaucoma patients provides parameters to discriminate between mild and severe glaucoma and to determine whether DTI derived indices correlate with retinal nerve fibre layer (RNFL) thickness. Methods: 3-Tesla DTI was performed on 90 subjects (30 normal, 30 mild glaucoma and 30 severe glaucoma subjects) and the FA and MD of the optic nerve and optic radiation were measured. The categorisation into mild and severe glaucoma was done using the Hodapp–Parrish–Anderson (HPA) classification. RNFL thickness was also assessed on all subjects using OCT. Receiver operating characteristic (ROC) analysis and Spearman's correlation coefficient was carried out. Results: FA and MD values in the optic nerve and optic radiation decreased and increased respectively as the disease progressed. FA at the optic nerve had the highest sensitivity (87%) and specificity (80%). FA values displayed the strongest correlation with RNFL thickness in the optic nerve (r = 0.684, p ≤ 0.001) while MD at the optic radiation showed the weakest correlation with RNFL thickness (r = −0.360, p ≤ 0.001). Conclusions: The high sensitivity and specificity of DTI-derived FA values in the optic nerve and the strong correlation between DTI-FA and RNFL thickness suggest that these parameters could serve as indicators of disease severity

Optical Properties of Nanoparticles and Nanocomposites

CSIR Research Space (South Africa)

Kumbhakar, P

2014-01-01

Full Text Available of ceria nanoparticles and degradation of Congo red (CR) dye under the visible light irradiation. We are very much happy to note the research progress on the techniques of synthesis, characterization, and optical properties of nanostructured materials. Also...

Optical observations of Gamma-Ray Bursts

International Nuclear Information System (INIS)

Hjorth, J.; Pian, E.; Fynbo, J.P.U.

2004-01-01

We briefly review the status and recent progress in the field of optical observations of gamma-ray burst afterglows. We will focus on the fundamental observational evidence for the relationship between gamma-ray bursts and the final evolutionary phases of massive stars. In particular, we will address (i) gamma-ray burst host galaxies, (ii) optically dark gamma-ray burst afterglows, (iii) the gamma-ray burst-supernova connection, and (iv) the relation between X-ray flashes, gamma-ray bursts, and supernovae

Diabetes mellitus, diabetes insipidus, optic atrophy, and deafness: A case of Wolfram (DIDMOAD) syndrome.

Science.gov (United States)

Maleki, Nasrollah; Bashardoust, Bahman; Zakeri, Anahita; Salehifar, Azita; Tavosi, Zahra

2015-01-01

To report a case of Wolfram syndrome (WS) characterized by diabetes mellitus, diabetes insipidus, progressive optic atrophy, and deafness. A 19-year-old female patient, a known case of diabetes mellitus type I from six years before, presented with progressive vision loss since four years earlier. On fundoscopic examination, she had bilateral optic atrophy without diabetic retinopathy. The patient also had diabetes insipidus, neurosensory deafness, and neurogenic bladder. WS should be considered a differential diagnosis in patients with diabetes mellitus who present with optic atrophy, and it is necessary to perform a hearing test as well as collecting 24-h urine output.

Progress on Chinese evaluated nuclear parameters library (CENPL). Pt. 3

International Nuclear Information System (INIS)

Su Zongdi; Ge Zhigang; Zhou Chunmei

1994-01-01

The progress on Chinese evaluated nuclear parameters library (CENPL) is introduced. The setting up work of each sub-library of CENPL has got some new progresses at the past period. These sub-libraries are atomic mass and characteristic constant for nuclear ground state sub-library, discrete level scheme and batch ratio of γ decay sub-library, level density parameter sub-library, giant dipole resonance parameter for γ-ray strength function sub-library and optical model parameter sub-library

Orphan disease: Cherubism, optic atrophy, and short stature.

Science.gov (United States)

Jeevanandham, Balaji; Ramachandran, Rajoo; Dhanapal, Vignesh; Subramanian, Ilanchezhian; Sai, Venkata

2018-01-01

A 12-year-old female presented with complaints of progressive visual impairment in both her eyes. On clinical examination, she was short for her age and her ophthalmoscopic examination revealed bilateral optic atrophy. Computed tomography of the patient revealed multiple expansile lytic lesions of mandible suggesting cherubism. The optic atrophy was confirmed on magnetic resonance imaging, which additionally revealed bilateral retrocerebellar arachnoid cysts. This association of cherubism with optic atrophy and short stature was grouped as orphan disease by National Institutes of Health and only one case was reported in the literature so far.

Sensitive optical biosensors for unlabeled targets: A review

International Nuclear Information System (INIS)

Fan Xudong; White, Ian M.; Shopova, Siyka I.; Zhu Hongying; Suter, Jonathan D.; Sun Yuze

2008-01-01

This article reviews the recent progress in optical biosensors that use the label-free detection protocol, in which biomolecules are unlabeled or unmodified, and are detected in their natural forms. In particular, it will focus on the optical biosensors that utilize the refractive index change as the sensing transduction signal. Various optical label-free biosensing platforms will be introduced, including, but not limited to, surface plasmon resonance, interferometers, waveguides, fiber gratings, ring resonators, and photonic crystals. Emphasis will be given to the description of optical structures and their respective sensing mechanisms. Examples of detecting various types of biomolecules will be presented. Wherever possible, the sensing performance of each optical structure will be evaluated and compared in terms of sensitivity and detection limit

Computed tomography in orbital fractures and optic nerve trauma

International Nuclear Information System (INIS)

Dietrich, U.; Sievers, K.; Feldges, A.; Nau, H.E.

1990-01-01

Ten patients with orbital fractures and optic nerve trauma are reported. Fractures of the optic canal could be demonstrated by computed tomography in six cases and fractures of the orbital apex in another three cases. Surgical decompression of the optic canal was performed in seven cases. Computed tomography enhanced decision for surgery in cases of intraorbital haematoma with exophthalmus and narrowing of the canal by bony fragments, especially in those patients presenting with incomplete or progressive visual disturbance. (orig.) [de

Mathieu Progressive Waves

International Nuclear Information System (INIS)

Utkin, Andrei B.

2011-01-01

A new family of exact solutions to the wave equation representing relatively undistorted progressive waves is constructed using separation of variables in the elliptic cylindrical coordinates and one of the Bateman transforms. The general form of this Bateman transform in an orthogonal curvilinear cylindrical coordinate system is discussed and a specific problem of physical feasibility of the obtained solutions, connected with their dependence on the cyclic coordinate, is addressed. The limiting case of zero eccentricity, in which the elliptic cylindrical coordinates turn into their circular cylindrical counterparts, is shown to correspond to the focused wave modes of the Bessel-Gauss type. (electromagnetism, optics, acoustics, heat transfer, classical mechanics, and fluid dynamics)

Quantum optical arbitrary waveform manipulation and measurement in real time.

Science.gov (United States)

Kowligy, Abijith S; Manurkar, Paritosh; Corzo, Neil V; Velev, Vesselin G; Silver, Michael; Scott, Ryan P; Yoo, S J B; Kumar, Prem; Kanter, Gregory S; Huang, Yu-Ping

2014-11-17

We describe a technique for dynamic quantum optical arbitrary-waveform generation and manipulation, which is capable of mode selectively operating on quantum signals without inducing significant loss or decoherence. It is built upon combining the developed tools of quantum frequency conversion and optical arbitrary waveform generation. Considering realistic parameters, we propose and analyze applications such as programmable reshaping of picosecond-scale temporal modes, selective frequency conversion of any one or superposition of those modes, and mode-resolved photon counting. We also report on experimental progress to distinguish two overlapping, orthogonal temporal modes, demonstrating over 8 dB extinction between picosecond-scale time-frequency modes, which agrees well with our theory. Our theoretical and experimental progress, as a whole, points to an enabling optical technique for various applications such as ultradense quantum coding, unity-efficiency cavity-atom quantum memories, and high-speed quantum computing.

Elastic hadron scattering and optical theorem

CERN Document Server

Lokajicek, Milos V.; Prochazka, Jiri

2014-01-01

In principle all contemporary phenomenological models of elastic hadronic scattering have been based on the assumption of optical theorem validity that has been overtaken from optics. It will be shown that the given theorem which has not been actually proved cannot be applied to short-ranged strong interactions in any case. The actual progress in description of collision processes might then exist only if the initial states are specified on the basis of impact parameter values of colliding particles and probability dependence on this parameter is established.

Detection of Progressive Retinal Nerve Fiber Layer Loss in Glaucoma Using Scanning Laser Polarimetry with Variable Corneal Compensation

Science.gov (United States)

Medeiros, Felipe A.; Alencar, Luciana M.; Zangwill, Linda M.; Bowd, Christopher; Vizzeri, Gianmarco; Sample, Pamela A.; Weinreb, Robert N.

2010-01-01

Purpose To evaluate the ability of scanning laser polarimetry with variable corneal compensation to detect progressive retinal nerve fiber layer (RNFL) loss in glaucoma patients and patients suspected of having the disease. Methods This was an observational cohort study that included 335 eyes of 195 patients. Images were obtained annually with the GDx VCC scanning laser polarimeter, along with optic disc stereophotographs and standard automated perimetry (SAP) visual fields. The median follow-up time was 3.94 years. Progression was determined using commercial software for SAP and by masked assessment of optic disc stereophotographs performed by expert graders. Random coefficient models were used to evaluate the relationship between RNFL thickness measurements over time and progression as determined by SAP and/or stereophotographs. Results From the 335 eyes, 34 (10%) showed progression over time by stereophotographs and/or SAP. Average GDx VCC measurements decreased significantly over time for both progressors as well as non-progressors. However, the rate of decline was significantly higher in the progressing group (−0.70 μm/year) compared to the non-progressing group (−0.14 μm/year; P = 0.001). Black race and male sex were significantly associated with higher rates of RNFL loss during follow-up. Conclusions The GDx VCC scanning laser polarimeter was able to identify longitudinal RNFL loss in eyes that showed progression in optic disc stereophotographs and/or visual fields. These findings suggest that this technology could be useful to detect and monitor progressive disease in patients with established diagnosis of glaucoma or suspected of having the disease. PMID:19029038

EDITORIAL: Special section: Selected papers from OMS'05, the 1st Topical Meeting of the European Optical Society on Optical Microsystems (OMS)

Science.gov (United States)

Rendina, Ivo; Fazio, Eugenio; Ferraro, Pietro

2006-07-01

OMS'05 is the first international conference wholly dedicated to optical microsystems. It was organized by the European Optical Society (EOS) in the frame of its international topical meeting activity and was held in Italy, September 2005, amidst the wonderful scenery of the Island of Capri. A possible definition of an optical microsystem is a complex system, able to perform one or more sensing and actuation functions, where optical devices are integrated in a smart way with electronic, mechanical and sensing components by taking advantage of the progress in micro- and nano-technologies. The increasing interest in this field arises from the expected applications that would significantly improve the quality of life. The list of possibilities offered by the optical microsystem enabling technologies is very long and seems to increase day by day. We are not only thinking about the next generation of optical telecommunication networks and computers, but also about low-cost, compact microsystems for environmental monitoring, in order to improve safety in the avionic and automotive fields, medical diagnostics and proteomic/genomic studies, or just finding general applications in several industrial fields. The goal of the conference was to involve scientists and young researchers from the main public and private laboratories, giving them the opportunity to present new scientific results and compare their know-how in the exciting and emerging field of optical microsystems. We believe that we succeeded in this. More than 200 scientists from all over the world attended the conference. We had more than 100 oral presentations and approximately 20 from the keynote lectures and invited speeches. It was an opportunity to define the most recent progress carried out in the field and to outline the possible road-map leading to the expected results in the industrial and social fields. We strongly believe that research and technology are closely interconnected at present and cannot

Optics and Fluid Dynamics Department. Annual progress report 1 January - 31 December 1991

International Nuclear Information System (INIS)

Juul Rasmussen, J.; Hanson, S.G.

1992-03-01

Research in the Optics and Fluid Dynamics Department covers quasi-elastic light scattering, optical and electronic information processing, continuum physics and activities in connection with the Euratom fusion association. A summary of activities in 1991 is presented. Optical diagnostic methods based on quasielastic light scattering have been developed. Beam propagation in random and nonlinear media has been investigated. Spatial and temporal processing schemes, especially for pattern recognition, have been investigated. Within the area of fluid dynamics spectral models for studying the dynamics of coherent structures have been developed. Coherent structures have been investigated in a plasma and are now also investigated in a rotating fluid. Fusion relevant work performed under the Euratom association includes investigations of turbulent transport and the development of diagnostic methods. A special activity is concentrated on the development of pellet injection systems for fusion research. (au) (1 tab., 20 ills., 37 refs.)

The fiber-optic imaging and manipulation of neural activity during animal behavior.

Science.gov (United States)

Miyamoto, Daisuke; Murayama, Masanori

2016-02-01

Recent progress with optogenetic probes for imaging and manipulating neural activity has further increased the relevance of fiber-optic systems for neural circuitry research. Optical fibers, which bi-directionally transmit light between separate sites (even at a distance of several meters), can be used for either optical imaging or manipulating neural activity relevant to behavioral circuitry mechanisms. The method's flexibility and the specifications of the light structure are well suited for following the behavior of freely moving animals. Furthermore, thin optical fibers allow researchers to monitor neural activity from not only the cortical surface but also deep brain regions, including the hippocampus and amygdala. Such regions are difficult to target with two-photon microscopes. Optogenetic manipulation of neural activity with an optical fiber has the advantage of being selective for both cell-types and projections as compared to conventional electrophysiological brain tissue stimulation. It is difficult to extract any data regarding changes in neural activity solely from a fiber-optic manipulation device; however, the readout of data is made possible by combining manipulation with electrophysiological recording, or the simultaneous application of optical imaging and manipulation using a bundle-fiber. The present review introduces recent progress in fiber-optic imaging and manipulation methods, while also discussing fiber-optic system designs that are suitable for a given experimental protocol. Copyright © 2015 The Authors. Published by Elsevier Ireland Ltd.. All rights reserved.

Orphan disease: Cherubism, optic atrophy, and short stature

OpenAIRE

Balaji Jeevanandham; Rajoo Ramachandran; Vignesh Dhanapal; Ilanchezhian Subramanian; Venkata Sai

2018-01-01

A 12-year-old female presented with complaints of progressive visual impairment in both her eyes. On clinical examination, she was short for her age and her ophthalmoscopic examination revealed bilateral optic atrophy. Computed tomography of the patient revealed multiple expansile lytic lesions of mandible suggesting cherubism. The optic atrophy was confirmed on magnetic resonance imaging, which additionally revealed bilateral retrocerebellar arachnoid cysts. This association of cherubism wit...

Solar Adaptive Optics.

Science.gov (United States)

Rimmele, Thomas R; Marino, Jose

Adaptive optics (AO) has become an indispensable tool at ground-based solar telescopes. AO enables the ground-based observer to overcome the adverse effects of atmospheric seeing and obtain diffraction limited observations. Over the last decade adaptive optics systems have been deployed at major ground-based solar telescopes and revitalized ground-based solar astronomy. The relatively small aperture of solar telescopes and the bright source make solar AO possible for visible wavelengths where the majority of solar observations are still performed. Solar AO systems enable diffraction limited observations of the Sun for a significant fraction of the available observing time at ground-based solar telescopes, which often have a larger aperture than equivalent space based observatories, such as HINODE. New ground breaking scientific results have been achieved with solar adaptive optics and this trend continues. New large aperture telescopes are currently being deployed or are under construction. With the aid of solar AO these telescopes will obtain observations of the highly structured and dynamic solar atmosphere with unprecedented resolution. This paper reviews solar adaptive optics techniques and summarizes the recent progress in the field of solar adaptive optics. An outlook to future solar AO developments, including a discussion of Multi-Conjugate AO (MCAO) and Ground-Layer AO (GLAO) will be given. Supplementary material is available for this article at 10.12942/lrsp-2011-2.

Folic acid deficiency optic neuropathy: A case report

Directory of Open Access Journals (Sweden)

de Silva Punyanganie

2008-09-01

Full Text Available Abstract Introduction Nutritional optic neuropathies are uncommon and can be associated with gradual visual loss and optic atrophy or sudden vision loss and optic disc swelling. Case presentation A 44-year-old woman presented with a 4-week history of progressive visual loss and was noted to have bilateral retrobulbar optic neuropathy. No other clinical abnormality was noted. Investigations revealed severe folate deficiency with normal vitamin B12 levels. Her alcohol and tobacco consumption was moderate and subsequent correction of folate levels with oral supplementation has led to improvement in her visual acuity. Conclusion This case highlights an unusual presentation of folic acid deficiency that may present to the general physician.

Multispectral optical tweezers for molecular diagnostics of single biological cells

Science.gov (United States)

Butler, Corey; Fardad, Shima; Sincore, Alex; Vangheluwe, Marie; Baudelet, Matthieu; Richardson, Martin

2012-03-01

Optical trapping of single biological cells has become an established technique for controlling and studying fundamental behavior of single cells with their environment without having "many-body" interference. The development of such an instrument for optical diagnostics (including Raman and fluorescence for molecular diagnostics) via laser spectroscopy with either the "trapping" beam or secondary beams is still in progress. This paper shows the development of modular multi-spectral imaging optical tweezers combining Raman and Fluorescence diagnostics of biological cells.

Progress of optical sensor system for health monitoring of bridges at Chongqing University

Science.gov (United States)

Chen, W.; Fu, Y.; Zhu, Y.; Huang, S.

2005-02-01

With decades of research experience on optical sensors, Optoelectronic Technology Lab of Chongqing University (OTLCU) has studied on a variety of sensors system designed for practical use in health monitoring. In OTLCU, embedded and surface mounted fiber Fabry-Perot strain sensor has been developed for monitoring the local strain of both concrete and steel truss bridge. Optoelectronic deflect meter, with a group of optical level sensor in a series connected pipe, was developed for deflection monitoring and line shape monitoring of the bridges. Laser deflect meter, with a laser pointer and a sensors array, has been also developed for a dynamic deflection monitoring of the bridges. To monitoring the 2-Dimentional displacement of the bridge, a self-calibrating imaging system was developed. All these sensor systems have been applied in different bridges successfully. This paper briefly describes principle of these optical sensing systems, and also gives some representative results of the system in practical application of bridges.

Optical fiber telecommunications systems and networks

CERN Document Server

Kaminow, Ivan; Willner, Alan E

2013-01-01

Optical Fiber Telecommunications VI (A&B) is the sixth in a series that has chronicled the progress in the R&D of lightwave communications since the early 1970s. Written by active authorities from academia and industry, this edition brings a fresh look to many essential topics, including devices, subsystems, systems and networks. A central theme is the enabling of high-bandwidth communications in a cost-effective manner for the development of customer applications. These volumes are an ideal reference for R&D engineers and managers, optical systems implementers, university researchers and s

Optical fiber telecommunications components and subsystems

CERN Document Server

Kaminow, Ivan; Willner, Alan E

2013-01-01

Optical Fiber Telecommunications VI (A&B) is the sixth in a series that has chronicled the progress in the R&D of lightwave communications since the early 1970s. Written by active authorities from academia and industry, this edition brings a fresh look to many essential topics, including devices, subsystems, systems and networks. A central theme is the enabling of high-bandwidth communications in a cost-effective manner for the development of customer applications. These volumes are an ideal reference for R&D engineers and managers, optical systems implementers, university researchers and s

Strained silicon as a new electro-optic material

DEFF Research Database (Denmark)

Jacobsen, Rune Shim; Andersen, Karin Nordström; Borel, Peter Ingo

2006-01-01

For decades, silicon has been the material of choice for mass fabrication of electronics. This is in contrast to photonics, where passive optical components in silicon have only recently been realized1, 2. The slow progress within silicon optoelectronics, where electronic and optical...... functionalities can be integrated into monolithic components based on the versatile silicon platform, is due to the limited active optical properties of silicon3. Recently, however, a continuous-wave Raman silicon laser was demonstrated4; if an effective modulator could also be realized in silicon, data...... processing and transmission could potentially be performed by all-silicon electronic and optical components. Here we have discovered that a significant linear electro-optic effect is induced in silicon by breaking the crystal symmetry. The symmetry is broken by depositing a straining layer on top...

Field instruments for real time in-situ crude oil concentration measurements

International Nuclear Information System (INIS)

Fuller, C.B.; Bonner, J.S.; Page, C.A.; Arrambide, G.; Sterling, M.C.Jr.; Ojo, T.O.

2003-01-01

Accidental oil spills, contaminant release during resuspension, storms, and harmful algal blooms are all episodic events that can effect coastal margins. It is important to quantitatively describe water and ecological quality evolution and predict the impact to these areas by such events, but traditional sampling methods miss environmental activity during cyclical events. This paper presents a new sampling approach that involves continuous, real-time in-situ monitoring to provide data for development of comprehensive modeling protocols. It gives spill response coordinators greater assurance in making decisions using the latest visualization tools which are based on a good understanding of the physical processes at work in pulsed events. Five sensors for rapid monitoring of crude oil concentrations in aquatic systems were described. The in-situ and ex-situ sensors can measure plume transport and estimate polycyclic aromatic hydrocarbon exposure concentrations to assess risk of toxicity. A brief description and evaluation of the following 5 sensors was provided: the LISST-100 by Sequoia Instrument, a submersible multi-angle laser scattering instrument; the AU-10 field fluorometer by Turner Designs, an ex-situ single wavelength fluorometer; the Flashlamp by WET Labs Inc., an in-situ single wavelength fluorometer; and, the ECO-FL3 and SAFire by WET Labs Inc., two in-situ multiple wavelength fluorometers. These instruments were used to analyze crude oil emissions of various concentrations. All of the instruments followed a linear response within the tested concentration range. At the lowest concentrations the LISST-100 was not as effective as the fluorometers because of limited particle volume for scatter. For the AU-10 field fluorometer, the highest concentrations tested were above the measurement range of the instrument. 6 refs., 5 figs

Orphan disease: Cherubism, optic atrophy, and short stature

Directory of Open Access Journals (Sweden)

Balaji Jeevanandham

2018-01-01

Full Text Available A 12-year-old female presented with complaints of progressive visual impairment in both her eyes. On clinical examination, she was short for her age and her ophthalmoscopic examination revealed bilateral optic atrophy. Computed tomography of the patient revealed multiple expansile lytic lesions of mandible suggesting cherubism. The optic atrophy was confirmed on magnetic resonance imaging, which additionally revealed bilateral retrocerebellar arachnoid cysts. This association of cherubism with optic atrophy and short stature was grouped as orphan disease by National Institutes of Health and only one case was reported in the literature so far.

Tocilizumab for giant cell arteritis with corticosteroid-resistant progressive anterior ischemic optic neuropathy.

Science.gov (United States)

Vionnet, Julien; Buss, Guillaume; Mayer, Cédric; Sokolov, Arseny A; Borruat, François-Xavier; Spertini, François

2017-10-01

Giant cell arteritis is an inflammatory disorder of the medium- and large-size arteries. Permanent visual loss related to arteritic anterior ischemic optic neuropathy is among the most serious complications of this disease and initial treatment usually consists of high dose corticosteroids. There is no consensus in the literature concerning the optimal therapeutic approach in giant cell arteritis patients with corticosteroid-resistant arteritic anterior ischemic optic neuropathy. A 73-year-old Caucasian female with biopsy-proven giant cell arteritis developed an acute visual loss of the right eye due to arteritic anterior ischemic optic neuropathy. Despite 5 daily methylprednisolone pulses, systemic symptoms persisted and rapid involvement of the controlateral eye was documented. Therefore, tocilizumab (humanised monoclonal antibody binding the human interleukin-6 receptor) was introduced as a potential salvage therapy with a swift consecutive resolution of the systemic symptoms and stabilization of the ophthalmic lesions. Although a late effect of steroids pulses cannot be formally ruled out in this dramatic situation, tocilizumab likely offered a decisive effect in preventing bilateral blindness and may have contributed to steroid tapering. Tocilizumab may represent a new early effective second-line treatment option in corticosteroid-resistant anterior ischemic optic neuropathy. More data are needed to confirm this observation and to evaluate the safety profile of this treatment. Copyright © 2017 Société française de rhumatologie. Published by Elsevier SAS. All rights reserved.

Precision force sensing with optically-levitated nanospheres

Science.gov (United States)

Geraci, Andrew

2017-04-01

In high vacuum, optically-trapped dielectric nanospheres achieve excellent decoupling from their environment and experience minimal friction, making them ideal for precision force sensing. We have shown that 300 nm silica spheres can be used for calibrated zeptonewton force measurements in a standing-wave optical trap. In this optical potential, the known spacing of the standing wave anti-nodes can serve as an independent calibration tool for the displacement spectrum of the trapped particle. I will describe our progress towards using these sensors for tests of the Newtonian gravitational inverse square law at micron length scales. Optically levitated dielectric objects also show promise for a variety of other precision sensing applications, including searches for gravitational waves and other experiments in quantum optomechanics. National Science Foundation PHY-1205994, PHY-1506431, PHY-1509176.

Electro-optically actuated liquid-lens zoom

Science.gov (United States)

Pütsch, O.; Loosen, P.

2012-06-01

Progressive miniaturization and mass market orientation denote a challenge to the design of dynamic optical systems such as zoom-lenses. Two working principles can be identified: mechanical actuation and application of active optical components. Mechanical actuation changes the focal length of a zoom-lens system by varying the axial positions of optical elements. These systems are limited in speed and often require complex coupled movements. However, well established optical design approaches can be applied. In contrast, active optical components change their optical properties by varying their physical structure by means of applying external electric signals. An example are liquidlenses which vary their curvatures to change the refractive power. Zoom-lenses benefit from active optical components in two ways: first, no moveable structures are required and second, fast response characteristics can be realized. The precommercial development of zoom-lenses demands simplified and cost-effective system designs. However the number of efficient optical designs for electro-optically actuated zoom-lenses is limited. In this paper, the systematic development of an electro-optically actuated zoom-lens will be discussed. The application of aberration polynomials enables a better comprehension of the primary monochromatic aberrations at the lens elements during a change in magnification. This enables an enhanced synthesis of the system behavior and leads to a simplified zoom-lens design with no moving elements. The change of focal length is achieved only by varying curvatures of targeted integrated electro-optically actuated lenses.

Adjuvant effect of Chakshushya Rasayana with beta-blocker eye drops in the management of progressive glaucomatous optic neuropathy: An open-label randomized controlled trial.

Science.gov (United States)

Dhiman, K S; Adhoor, Veeranagouda S; Agarwal, Riju; Mehta, Amit J

2016-01-01

Primary open angle glaucoma is an insidious and chronic vision-threatening eye ailment due to neuro-retino-optic nerve degeneration, which may be due to the raised intraocular pressure (IOP) or due to independent factors. Management of glaucoma is mainly concentrated on lowering IOP that requires lifetime topical medication, different ocular medicaments for lowering of IOP, and surgical interventions, but it has its own limitations to control the progression of glaucomatous optic neuropathy (GON), and this is the reason behind the use of alternative neuroprotective adjuvants. To evaluate the neuroprotective effect of Ayurvedic line of management of progressive GON. Ingredients of trial drug Vara Fort powder ( Chakshushya Rasayana ) were procured from the Institute Pharmacy, except Swarnamakshika Bhasma , which was purchased from Dhootapapeshwar Pharmaceuticals. The patients fulfilling inclusion criteria, attending outpatient and inpatient departments, irrespective of their sex, race, religion, occupation, etc., were selected and divided into two groups with open-labeled randomization. In Group A, in addition to betaxolol (0.1%) or timolol (0.5%) (non-iobrim), Chakshushya Rasayana 6 g/day orally with Triphala Ghrita and honey along with Koshtha-Shuddhi (body-microchannel clearing treatment) protocol was tried. Nasya (oleation through nasal route) with Jeevantyadi Taila and Tarpana (eye satiation) with Go-Ghrita were also performed. In Group B (control), brimonidine (iobrim) 0.2% eye drop was used for 3 months. Significant improvement was observed in subjective parameters in Group A such as blurred vision, frequent change of presbyopic glasses, and delayed dark adaptation. Chakshushya Rasayana , if administered in a systematic approach along with a modern topical betaxolol or timolol eye drops, has a definite role in improving the lost retinal sensitivity as much as up to 12 dB in 3 months duration.

Micro/Nanofibre Optical Sensors: Challenges and Prospects

Directory of Open Access Journals (Sweden)

Limin Tong

2018-03-01

Full Text Available Micro/nanofibres (MNFs are optical fibres with diameters close to or below the vacuum wavelength of visible or near-infrared light. Due to its wavelength- or sub-wavelength scale diameter and relatively large index contrast between the core and cladding, an MNF can offer engineerable waveguiding properties including optical confinement, fractional evanescent fields and surface intensity, which is very attractive to optical sensing on the micro and nanometer scale. In particular, the waveguided low-loss tightly confined large fractional evanescent fields, enabled by atomic level surface roughness and extraordinary geometric and material uniformity in a glass MNF, is one of its most prominent merits in realizing optical sensing with high sensitivity and great versatility. Meanwhile, the mesoporous matrix and small diameter of a polymer MNF, make it an excellent host fibre for functional materials for fast-response optical sensing. In this tutorial, we first introduce the basics of MNF optics and MNF optical sensors, and review the progress and current status of this field. Then, we discuss challenges and prospects of MNF sensors to some extent, with several clues for future studies. Finally, we conclude with a brief outlook for MNF optical sensors.

Evaluation of acute radiation optic neuropathy by B-scan ultrasonography

International Nuclear Information System (INIS)

Lovato, A.A.; Char, D.H.; Quivey, J.M.; Castro, J.R.

1990-01-01

We studied the accuracy of B-scan ultrasonography to diagnose radiation-induced optic neuropathy in 15 patients with uveal melanoma. Optic neuropathy was diagnosed by an observer masked as to clinical and photographic data. We analyzed planimetry area measurements of the retrobulbar nerve before and after irradiation. The retrobulbar area of the optic nerve shadow on B-scan was quantitated with a sonic digitizer. Increased optic nerve shadow area was confirmed in 13 of 15 patients who had radiation optic neuropathy (P less than .004). The correct diagnosis was confirmed when the results of ultrasound were compared to fundus photography and fluorescein angiography. In 13 patients there was acute radiation optic neuropathy. Two patients did not show an enlarged retrobulbar optic nerve, and the clinical appearance suggested early progression to optic atrophy. Ultrasonography documents the enlargement of the optic nerve caused by acute radiation changes

Observation and measurement of interaction-induced dispersive optical nonlinearities in an ensemble of cold rydberg atoms

DEFF Research Database (Denmark)

Parigi, V.; Bimbard, E.; Stanojevic, J.

2012-01-01

We observe and measure dispersive optical nonlinearities in an ensemble of cold Rydberg atoms placed inside an optical cavity. The experimental results are in agreement with a simple model where the optical nonlinearities are due to the progressive appearance of a Rydberg blockaded volume within...

Recent Progress of the Synchrotron Radiation Calculation Code SPECTRA

International Nuclear Information System (INIS)

Tanaka, T.; Kitamura, H.

2007-01-01

SPECTRA is a computer software to calculate optical properties of synchrotron radiation (SR) emitted by electrons passing through magnetic devices such as bending magnets, wigglers and undulators. It has been used to design various devices in the SR beamline, such as high heat-load components in the front-end section and optical elements in the optics hutch. In addition, the electron beam quality can be estimated by comparison between the measured and calculated properties of SR. Since the first announcement, numerous improvements have been made to SPECTRA to achieve less computation time with higher numerical accuracy. In addition, a number of functions have been added to follow the user's demand. In this paper, recent progress of SPECTRA is presented and details of the new functions are explained together with several examples

Research program in elementary particle theory: Progress report, January 1, 1988-December 1988

International Nuclear Information System (INIS)

Sudarshan, E.C.G.; Dicus, D.A.

1988-08-01

This report discusses progress in the following areas: Mathematical Physics, Strings and Gauge Theories; Quantum Optics; High Energy Phenomenology; Angular Momentum, QCD Sum Rules; and Application of Particle Physics to Astrophysics

Progress in optical-field-ionization soft x-ray lasers at LOA

Czech Academy of Sciences Publication Activity Database

Mocek, Tomáš; Sebban, S.; Bettaibi, I.; Zeitoun, P.; Faivre, G.; Cros, B.; Maynard, G.; Butler, A.; McKenna, C.M.; Spence, D.J.; Gonsavles, A.J.; Hooker, S.M.; Vorontsov, V.; Hallou, S.; Fajardo, M.; Kazamias, S.; Le Pape, S.; Mercere, P.; Morlens, A.S.; Valentin, C.; Balcou, P.

2005-01-01

Roč. 23, - (2005), s. 351-356 ISSN 0263-0346 Grant - others:EU(XE) HPRI-1999-CT-00086; EU(XE) HPMF-CT-2002-01554 Institutional research plan: CEZ:AV0Z10100523 Keywords : collisional excitation * femtosecond * guiding * high harmonic amplification * x-ray laser Subject RIV: BH - Optics, Masers, Lasers Impact factor: 2.590, year: 2005

Theoretical aspects of the optical model

International Nuclear Information System (INIS)

Mahaux, C.

1980-01-01

We first recall the definition of the optical-model potential for nucleons and the physical interpretation of the main related quantities. We then survey the recent theoretical progress towards a reliable calculation of this potential. The present limitations of the theory and some prospects for future developments are outlined. (author)

ONU power saving modes in next generation optical access networks: progress, efficiency and challenges.

Science.gov (United States)

Dixit, Abhishek; Lannoo, Bart; Colle, Didier; Pickavet, Mario; Demeester, Piet

2012-12-10

The optical network unit (ONU), installed at a customer's premises, accounts for about 60% of power in current fiber-to-the-home (FTTH) networks. We propose a power consumption model for the ONU and evaluate the ONU power consumption in various next generation optical access (NGOA) architectures. Further, we study the impact of the power savings of the ONU in various low power modes such as power shedding, doze and sleep.

Optical Detection of Non-amplified Genomic DNA

Science.gov (United States)

Li, Di; Fan, Chunhai

Nucleic acid sequences are unique to every living organisms including animals, plants and even bacteria and virus, which provide a practical molecular target for the identification and diagnosis of various diseases. DNA contains heterocyclic rings that has inherent optical absorbance at 260 nm, which is widely used to quantify single and double stranded DNA in biology. However, this simple quantification method could not differentiate sequences; therefore it is not suitable for sequence-specific analyte detection. In addition to a few exceptions such as chiral-related circular dichroism spectra, DNA hybridization does not produce significant changes in optical signals, thus an optical label is generally needed for sequence-specific DNA detection with optical means. During the last two decades, we have witnessed explosive progress in the area of optical DNA detection, especially with the help of simultaneously rapidly developed nanomaterials. In this chapter, we will summarize recent advances in optical DNA detection including colorimetric, fluorescent, luminescent, surface plasmon resonance (SPR) and Raman scattering assays. Challenges and problems remained to be addressed are also discussed.

Fabrication of biconical tapered optical fibers using hydrofluoric acid

International Nuclear Information System (INIS)

Haddock, Hong S.; Shankar, P.M.; Mutharasan, R.

2003-01-01

An easy to implement procedure for etching silica fibers in biconical form useful in sensing applications is described. A simple etching reactor was developed to obtain reproducible tapers of desired diameter and length. An approach for on-line monitoring of etching using a commonly used fluorometer is demonstrated. A mathematical model describing the light power transmission is proposed, and is validated using experimental data. The data and the model indicate that the diameter of the silica fiber decreases linearly with time with hydrofluoric acid (HF, 49.5% w/w) used as etchant at room temperature. The observed etching rate was 0.0023±0.00019 s -1 , which was repeatable using the procedure developed in this study. Method to arrest etching and subsequent preservation of the small diameter taper in mildly alkaline solution was found to be successful

Progress in Ultrafast Intense Laser Science

CERN Document Server

Yamanouchi, Kaoru; Li, Ruxin; Chin, See Leang

2009-01-01

The PUILS series presents Progress in Ultrafast Intense Laser Science, a newly emerging interdisciplinary research field spanning atomic and molecular physics, molecular science, and optical science. PUILS has been stimulated by the recent development of ultrafast laser technologies. Each volume contains approximately 15 chapters, authored by researchers at the forefront. Each chapter opens with an overview of the topics to be discussed, so that researchers, who are not experts in the specific topics, as well as graduate students can grasp the importance and attractions of this sub-field of research, and these are followed by reports of cutting-edge discoveries. This fourth volume covers a broad range of topics from this interdisciplinary research field, focusing on strong field ionization of atoms; excitation, ionization and fragmentation of molecules; nonlinear intense optical phenomena and attosecond pulses; and laser - solid interactions and photoemission.

Optical fibre sensing of plasmas

International Nuclear Information System (INIS)

Woolsey, G.A.; Scelsi, G.B.

2000-01-01

The progress of optical fiber technology for communications has induced an interest in, among others, the sensing of a wide range of physical, and chemical quantities. Any application of optical fibers that are crucial for communication are significant for sensing, e.g. small dimension, insulating materials, immunity to high voltage field etc. In the present paper basic points of optical fiber sensing are summarized. It is noted optical fiber sensors come in two forms, intrinsic and extrinsic. In the former the fiber itself works as sensing element, in addition to data transmission lines. In an intrinsic sensor, a single fiber transmits the light from the source to the detector and the light is modulated while it is in the fiber. On the other hand, in the extrinsic sensor, the light leaves the input fiber to be modulated before being collected by the second output fiber. Characteristic of the light that can be modulated are amplitude, phase, polarization, and wavelength. The paper describes the modulation in some details. (author)

Optical fibre sensing of plasmas

Energy Technology Data Exchange (ETDEWEB)

Woolsey, G.A.; Scelsi, G.B. [School of Physical Sciences and Engineering, Univ. of New England, Armidale, NSW (Australia)

2000-03-01

The progress of optical fiber technology for communications has induced an interest in, among others, the sensing of a wide range of physical, and chemical quantities. Any application of optical fibers that are crucial for communication are significant for sensing, e.g. small dimension, insulating materials, immunity to high voltage field etc. In the present paper basic points of optical fiber sensing are summarized. It is noted optical fiber sensors come in two forms, intrinsic and extrinsic. In the former the fiber itself works as sensing element, in addition to data transmission lines. In an intrinsic sensor, a single fiber transmits the light from the source to the detector and the light is modulated while it is in the fiber. On the other hand, in the extrinsic sensor, the light leaves the input fiber to be modulated before being collected by the second output fiber. Characteristic of the light that can be modulated are amplitude, phase, polarization, and wavelength. The paper describes the modulation in some details. (author)

Advances in condensed matter optics

CERN Document Server

Chen, Liangyao; Jiang, Xunya; Jin, Kuijuan; Liu, Hui; Zhao, Haibin

2015-01-01

This book describes some of the more recent progresses and developmentsin the study of condensed matter optics in both theoretic and experimental fields.It will help readers, especially graduate students and scientists who are studying and working in the nano-photonic field, to understand more deeply the characteristics of light waves propagated in nano-structure-based materials with potential applications in the future.

Cataract and progressing keratoconus — solution?

Directory of Open Access Journals (Sweden)

K. B. Pershin

2015-01-01

Full Text Available Purpose: To develop an uniform method of the treatment for patients with progressive keratoconus (stage 1‑2 and cataract. Patients and methods: 4 patients (5 eyes with cataract and progressive keratoconus stage 1‑2 were enrolled in the study. Mean age was 42 years. In all patients, standard ophthalmic examination as well corneal topography, anterior segment optical coherence tomography, biometry, and IOL power calculations using IOLMaster were performed. Mean uncorrected visual acuity (UCVA was 0.1 while mean best-corrected visual acuity (BCVA was 0.4. Surgical technique included two steps. The first step was the creation of corneal tunnels with femtosecond laser with subsequent phaco and monofocal aspheric IOL implantation. The second step (1‑2 weeks later was the implantation of intrastromal ring segments based on corneal topography and corneal crosslinking.Results: After the first step, all patients had myopic refraction (from –1.0 D to –2.5 D. Cylindrical component was almost unchanged. After the second step, the patients reported the vision improvement, mainly due to UCVA. Both spherical (myopic and cylindrical components decreased, mainly due to the steep meridian. After the treatment, optical power of the cornea decreased, mainly due to the steep meridian. UCVA was 0.6 or more in 60 % of cases, final BCVA was 0.8‑1.0 in 80 % of cases. Neither intraoperative nor postoperative (follow-up was 2 years complications were observed.Conclusions: Combined phaco and prior creation of corneal tunnels with subsequent intrastromal ring segment implantation and crosslinking in patients with cataract and progressive keratoconus stage 1‑2 is safe, provides good predictable outcome and significantly reduces rehabilitation period.

The OPTICON technology roadmap for optical and infrared astronomy

Science.gov (United States)

Cunningham, Colin; Melotte, David; Molster, Frank

2010-07-01

The Key Technology Network (KTN) within the OPTICON programme has been developing a roadmap for the technology needed to meet the challenges of optical and infrared astronomy over the next few years, with particular emphasis on the requirements of Extremely Large Telescopes. The process and methodology so far will be described, along with the most recent roadmap. The roadmap shows the expected progression of ground-based astronomy facilities and the technological developments which will be required to realise these new facilities. The roadmap highlights the key stages in the development of these technologies. In some areas, such as conventional optics, gradual developments in areas such as light-weighting of optics will slowly be adopted into future instruments. In other areas, such as large area IR detectors, more rapid progress can be expected as new processing techniques allow larger and faster arrays. Finally, other areas such as integrated photonics have the potential to revolutionise astronomical instrumentation. Future plans are outlined, in particular our intention to look at longer term development and disruptive technologies.

Bridge SHM system based on fiber optical sensing technology

Science.gov (United States)

Li, Sheng; Fan, Dian; Fu, Jiang-hua; Huang, Xing; Jiang, De-sheng

2015-09-01

The latest progress of our lab in recent 10 years on the area of bridge structural health monitoring (SHM) based on optical fiber sensing technology is introduced. Firstly, in the part of sensing technology, optical fiber force test-ring, optical fiber vibration sensor, optical fiber smart cable, optical fiber prestressing loss monitoring method and optical fiber continuous curve mode inspection system are developed, which not only rich the sensor types, but also provides new monitoring means that are needed for the bridge health monitoring system. Secondly, in the optical fiber sensing network and computer system platform, the monitoring system architecture model is designed to effectively meet the integration scale and effect requirement of engineering application, especially the bridge expert system proposed integration of sensing information and informatization manual inspection to realize the mode of multi index intelligence and practical monitoring, diagnosis and evaluation. Finally, the Jingyue bridge monitoring system as the representative, the research on the technology of engineering applications are given.

Progress in nanophotonics 1

Energy Technology Data Exchange (ETDEWEB)

Ohtsu, Motoichi (ed.) [Tokyo Univ. (Japan). Graduate School of Engineering

2011-07-01

This book focuses on the recent progress in nanophotonics technology to be used to develop novel nano-optical devices, fabrication technology, and security systems. It begins with a review of the concept of dressed photons and applications to devices, fabrication, and systems; principles and applications. Further topics include: DNA process for quantum dot chain, photon enhanced emission microscopy, near field spectroscopy of metallic nanostructure, self-organized fabrication of composite semiconductor quantum dots, formation of metallic nanostructure, and nanophotonic information systems with security. These topics are reviewed by seven leading scientists. This overview is a variable resource for engineers and scientists working in the field of nanophotonics. (orig.)

The 1989 progress report: Polytechnic school laboratories' Direction

International Nuclear Information System (INIS)

1989-01-01

The 1989 progress report of the laboratories' Direction of the Polytechnic School (France) is presented. The research activities carried out in each laboratory are summarized. Scientific and technical cooperation, financial and employement aspects are included. The main fields of research are: biochemistry, chemistry, reaction mechanisms, organic synthesis, mechanics of solids, meteorology, irradiated solids, optics, physics, biophysics, lasers, mathematics, econometrics, epistemology, management and computer science [fr

The OPTHER Project: Progress toward the THz Amplifier

DEFF Research Database (Denmark)

Paoloni, C; Brunetti, F; Di Carlo, A

2011-01-01

This paper describes the status of the OPTHER (OPtically driven TeraHertz AmplifiERs) project and progress toward the THz amplifier realization. This project represents a considerable advancement in the field of high frequency amplification. The design and realization of a THz amplifier within...... this project is a consolidation of efforts at the international level from the leading scientific and industrial European organizations working with vacuum electronics....

The Particle Beam Optics Interactive Computer Laboratory

International Nuclear Information System (INIS)

Gillespie, George H.; Hill, Barrey W.; Brown, Nathan A.; Babcock, R. Chris; Martono, Hendy; Carey, David C.

1997-01-01

The Particle Beam Optics Interactive Computer Laboratory (PBO Lab) is an educational software concept to aid students and professionals in learning about charged particle beams and particle beam optical systems. The PBO Lab is being developed as a cross-platform application and includes four key elements. The first is a graphic user interface shell that provides for a highly interactive learning session. The second is a knowledge database containing information on electric and magnetic optics transport elements. The knowledge database provides interactive tutorials on the fundamental physics of charged particle optics and on the technology used in particle optics hardware. The third element is a graphical construction kit that provides tools for students to interactively and visually construct optical beamlines. The final element is a set of charged particle optics computational engines that compute trajectories, transport beam envelopes, fit parameters to optical constraints and carry out similar calculations for the student designed beamlines. The primary computational engine is provided by the third-order TRANSPORT code. Augmenting TRANSPORT is the multiple ray tracing program TURTLE and a first-order matrix program that includes a space charge model and support for calculating single particle trajectories in the presence of the beam space charge. This paper describes progress on the development of the PBO Lab

Performance of confocal scanning laser tomograph Topographic Change Analysis (TCA) for assessing glaucomatous progression.

Science.gov (United States)

Bowd, Christopher; Balasubramanian, Madhusudhanan; Weinreb, Robert N; Vizzeri, Gianmarco; Alencar, Luciana M; O'Leary, Neil; Sample, Pamela A; Zangwill, Linda M

2009-02-01

To determine the sensitivity and specificity of confocal scanning laser ophthalmoscope's Topographic Change Analysis (TCA; Heidelberg Retina Tomograph [HRT]; Heidelberg Engineering, Heidelberg, Germany) parameters for discriminating between progressing glaucomatous and stable healthy eyes. The 0.90, 0.95, and 0.99 specificity cutoffs for various (n=70) TCA parameters were developed by using 1000 permuted topographic series derived from HRT images of 18 healthy eyes from Moorfields Eye Hospital, imaged at least four times. The cutoffs were then applied to topographic series from 36 eyes with known glaucomatous progression (by optic disc stereophotograph assessment and/or standard automated perimetry guided progression analysis, [GPA]) and 21 healthy eyes from the University of California, San Diego (UCSD) Diagnostic Innovations in Glaucoma Study (DIGS), all imaged at least four times, to determine TCA sensitivity and specificity. Cutoffs also were applied to 210 DIGS patients' eyes imaged at least four times with no evidence of progression (nonprogressed) by stereophotography or GPA. The TCA parameter providing the best sensitivity/specificity tradeoff using the 0.90, 0.95, and 0.99 cutoffs was the largest clustered superpixel area within the optic disc margin (CAREA(disc) mm(2)). Sensitivities/specificities for classifying progressing (by stereophotography and/or GPA) and healthy eyes were 0.778/0.809, 0.639/0.857, and 0.611/1.00, respectively. In nonprogressing eyes, specificities were 0.464, 0.570, and 0.647 (i.e., lower than in the healthy eyes). In addition, TCA parameter measurements of nonprogressing eyes were similar to those of progressing eyes. TCA parameters can discriminate between progressing and longitudinally observed healthy eyes. Low specificity in apparently nonprogressing patients' eyes suggests early progression detection using TCA.

Clinical Presentation and Outcome of Patients With Optic Pathway Glioma.

Science.gov (United States)

Robert-Boire, Viviane; Rosca, Lorena; Samson, Yvan; Ospina, Luis H; Perreault, Sébastien

2017-10-01

Optic pathway gliomas (OPGs) occur sporadically or in patients with neurofibromatosis type 1 (NF1). The purpose of this study was to evaluate the clinical presentation at diagnosis and at progression of patients with OPGs. We conducted a chart review of patients with OPGs diagnosed in a single center over a period of 15 years. Demographic data including age, sex, NF1 status, clinical presentation, and outcome were collected. Of the 40 patients who were identified, 23 had sporadic tumors (57.5%) and 17 had NF1-related tumors (42.5%). Among the children with NF1, there was a significant overrepresentation of girls (82.3%) (P = 0.02), while among the children without NF1, there were slightly more boys (56.5%) than girls (43.5%). The presence of nystagmus was strongly associated with sporadic optic pathway gliomas. Poor visual outcome was related to tumor affecting both optic pathways, hydrocephalus at diagnosis, and optic nerve atrophy. Of the 40 patients, five died of OPG complications (12.5%) and all had sporadic tumors. Our cohort is one of the largest with OPGs and a detailed description of the clinical presentation both at diagnosis and at progression. We observed a significant difference between sporadic and NF1 optic pathway gliomas in terms of demographics, clinical presentation, and outcome. Copyright © 2017 Elsevier Inc. All rights reserved.

AIRBORNE, OPTICAL REMOTE SENSING OF METHANE AND ETHANE FOR NATURAL GAS PIPELINE LEAK DETECTION

Energy Technology Data Exchange (ETDEWEB)

Jerry Myers

2003-11-12

Ophir Corporation was awarded a contract by the U. S. Department of Energy, National Energy Technology Laboratory under the Project Title ''Airborne, Optical Remote Sensing of Methane and Ethane for Natural Gas Pipeline Leak Detection'' on October 14, 2002. This second six-month technical report summarizes the progress made towards defining, designing, and developing the hardware and software segments of the airborne, optical remote methane and ethane sensor. The most challenging task to date has been to identify a vendor capable of designing and developing a light source with the appropriate output wavelength and power. This report will document the work that has been done to identify design requirements, and potential vendors for the light source. Significant progress has also been made in characterizing the amount of light return available from a remote target at various distances from the light source. A great deal of time has been spent conducting laboratory and long-optical path target reflectance measurements. This is important since it helps to establish the overall optical output requirements for the sensor. It also reduces the relative uncertainty and risk associated with developing a custom light source. The data gathered from the optical path testing has been translated to the airborne transceiver design in such areas as: fiber coupling, optical detector selection, gas filters, and software analysis. Ophir will next, summarize the design progress of the transceiver hardware and software development. Finally, Ophir will discuss remaining project issues that may impact the success of the project.

Microwave-optical double resonance spectroscopy. Progress report, February 1, 1976--January 31, 1977

Energy Technology Data Exchange (ETDEWEB)

Pratt, D.W.

1976-11-01

Zero-field and high-field optical detection of magnetic resonance (ODMR), electron paramagnetic resonance (EPR), and optical spectroscopy experiments have been performed on several systems in order to further basic knowledge of the structure, reactions, and response to radiation of atoms, molecules, and ions in their ground and/or excited electronic states. Particularly noteworthy results for the present contract year include the determination of the complete magnetic and optical properties of the lowest triplet states of 1-chloro, 1-bromo, and 1-iodonaphthalene, the development of a microscopic model for the intramolecular heavy-atom effect in the /sup 3/(..pi..,..pi..*) states of aromatic molecules, a detailed analysis of the angular dependence of the hyperfine and quadrupole structure in triplet 1-bromonaphthalene, observation of proton hyperfine structure in the hf ODMR spectra of short-lived triplet states, a definitive paper on the relative importance of spin delocalization and second-order spin-orbit coupling effects in /sup 3/(n,..pi..*) benzophenone (a phototype photochemical system), a detailed analysis of the level-anticrossing spectra of several triplet state benzophenones which exhibit hyperfine structure in the cross-relaxation region (thus permitting the determination of key magnetic parameters in the complete absence of perturbing microwave or radiofrequency fields), optical detection of ground-state NQR transitions in host crystal molecules, the observation of strong radiofrequency transitions near avoided crossing points in Zeeman energy level diagrams of photoexcited triplet states, the construction of zero-field ODMR, ODENDOR, and hf ODENDOR spectrometers, measurements of the activation parameters for ring interconversions of several free radicals containing five- and six-membered rings, and experimental proof that the triplet state of trimethylenemethane (a key reactive intermediate in organic chemistry) is the ground state.

Progress report 1 January - 31 December 1988. Department of Information Technology

International Nuclear Information System (INIS)

1989-04-01

This progress report describes the work carried out in the Department of Information Technology. The department comprises three sections. The Applied Laser Physics Section works in the areas of holographic optical elements, optical image processing, and the photorefractive effect. The Computer Section is primarily responsible for the central computer facilities and computer networks at Risoe. The Section for Information Processing and Cognitive Science, Sicos, is concerned with cognitive science, decision support, knowledge-based systems, and process simulation. Information given may be preliminary. (author) 1 tab., 9 ills., 46 refs

Optical Benson: Following the Impact of Melt Season Progression Using Landsat and Sentinel 2 - Snow Zone Formation Imaged

Science.gov (United States)

Fahnestock, M. A.; Shuman, C. A.; Alley, K. E.

2017-12-01

Snow pit observations on a glaciologically-focussed surface traverse in Greenland allowed Benson [1962, SIPRE (now CRREL) Research Report 70] to define a series of snow zones based on the extent of post-depositional diagenesis of the snowpack. At high elevations, Benson found fine-grained "dry snow" where melt (at that time) was absent year-round, followed down-elevation by a "percolation zone" where surface melt penetrated the snowpack, then a "wet snow zone" where firn became saturated during the peak of the melt season, and finally "superimposed ice" and "bare ice" zones where refrozen surface melt and glacier ice were exposed in the melt season. These snow zones can be discriminated in winter synthetic aperture radar (SAR) imagery of the ice sheet (e.g. Fahnestock et al. 2001), but summer melt reduces radar backscatter and makes it difficult to follow the progression of diagenesis beyond the initial indications of surface melting. While some of the impacts of surface melt (especially bands of blue water-saturated firn) are observed from time to time in optical satellite imagery, it has only become possible to map effects of melt over the course of a summer season with the advent of large-data analysis tools such as Google Earth Engine and the inclusion of Landsat and Sentinel-2 data streams in these tools. A map of the maximum extent of this blue saturated zone through the 2016 melt season is shown in the figure. This image is a true color (RGB) composite, but each pixel in the image shows the color of the surface when the "blueness" of the pixel was at a maximum. This means each pixel can be from a different satellite image acquisition than adjacent pixels - but it also means that the maximum extent of the saturated firn (Benson's wet snow zone) is visible. Also visible are percolation, superimposed and bare ice zones. This analysis, using Landsat 8 Operational Land Imager data, was performed using Google Earth Engine to access and analyze the entire melt

Automated data reduction for optical interferometric data

International Nuclear Information System (INIS)

Boyd, R.D.; Miller, D.J.; Ghiglia, D.C.

1983-01-01

The potential for significant progress in understanding many transport processes exists through the use of a rapid and automated data reduction process of optical interferometric data. An example involving natural convection in a horizontal annulus is used to demonstrate that the accuracy possible in automated techniques is better than 99.0%

Optically pumped terahertz sources

Institute of Scientific and Technical Information of China (English)

ZHONG Kai; SHI Wei; XU DeGang; LIU PengXiang; WANG YuYe; MEI JiaLin; YAN Chao; FU ShiJie; YAO JianQuan

2017-01-01

High-power terahertz (THz) generation in the frequency range of0.1-10 THz has been a fast-developing research area ever since the beginning of the THz boom two decades ago,enabling new technological breakthroughs in spectroscopy,communication,imaging,etc.By using optical (laser) pumping methods with near-or mid-infrared (IR) lasers,flexible and practical THz sources covering the whole THz range can be realized to overcome the shortage of electronic THz sources and now they are playing important roles in THz science and technology.This paper overviews various optically pumped THz sources,including femtosecond laser based ultrafast broadband THz generation,monochromatic widely tunable THz generation,single-mode on-chip THz source from photomixing,and the traditional powerful THz gas lasers.Full descriptions from basic principles to the latest progress are presented and their advantages and disadvantages are discussed as well.It is expected that this review gives a comprehensive reference to researchers in this area and additionally helps newcomers to quickly gain understanding of optically pumped THz sources.

Optically beamformed beam-switched adaptive antennas for fixed and mobile broadband wireless access networks

NARCIS (Netherlands)

Piqueras, M.A.; Grosskopf, G.; Vidal, B.; Herrera Llorente, J.; Martinez, J.M.; Sanchis, P.; Polo, V.; Corral, J.L.; Marceaux, A.; Galière, J.; Lopez, J.; Enard, A.; Valard, J.-L.; Parillaud, O.; Estèbe, E.; Vodjdani, N.; Choi, M.-S.; Besten, den J.H.; Soares, F.M.; Smit, M.K.; Marti, J.

2006-01-01

In this paper, a 3-bit optical beamforming architecture based in 2×2 optical switches and dispersive media is proposed and demonstrated. The performance of this photonic beamformer is experimentally demonstrated at 42.7 GHz in both transmission and reception modes. The progress achieved for

Forum metrology 2009: control of optics, targets and optical analyzers; Forum metrologie 2009: controle des optiques, cibles et analyseurs optiques

Energy Technology Data Exchange (ETDEWEB)

Desenne, D.; Andre, R.

2010-07-01

The 1. 'Forum Metrologie' of the CEA/DAM has been held in the 'Institut Laser et Plasma' on the December 9, 2009, close to the 'Centre d'etudes Scientifiques et Techniques d'Aquitaine'. It has been set up by the 'Departement Lasers de Puissance'. The chosen thematic was the metrology around laser experiments, with a special focus on the metrology of the dedicated optics, targets and optical analysers. The talks have shown the progress and difficulties in each of these fields. (authors)

Optical Coherence Tomography in Optic Nerve Hypoplasia: Correlation With Optic Disc Diameter, Nerve Fiber Layer Thickness, and Visual Function.

Science.gov (United States)

Kelly, John P; Baran, Francine; Phillips, James O; Weiss, Avery H

2017-12-15

The correlation between optic disc diameters (DDs) with average retinal nerve fiber layer thickness (RNFLT) and visual function in children with optic nerve hypoplasia (ONH) having nystagmus is unknown. Data were obtained from a retrospective review of 28 children (mean age: 9.4 years; ±5.1). Optic DD was defined as the maximal horizontal opening of Bruch membrane with spectral optical coherence tomography combined with a confocal laser ophthalmoscope. Average RNFLT was obtained from circumpapillary b-scans. RNFLT was also remeasured at eccentricities that were proportionate with DD to rule out potential sampling artifacts. Visual function was assessed by visual acuity at last follow-up and by visual evoked potentials (VEP) in 11 patients. The eye with the larger DD, which had better visual acuity, was analyzed to exclude potential effects of amblyopia. DD was correlated with average RNFLT (r = 0.61), visual acuity (r = 0.32), and VEPs (r = 0.66). The relationship between RNFLT and DD was as follows: average RNFLT (μm) = 0.074 * DD (μm) - 18.8. RNFLT also correlated with the ratio of horizontal optic DD to macula-disc-margin distance (DD:DM; r = 0.59). RNFLT measured at eccentricities proportionate with DD showed progressive decrease in thickness only for DDs <1,100 μm. All patients with DD <1,000 μm had subnormal visual acuity, whereas those with DD <1,200 μm had subnormal VEPs. DD correlates with average RNFLT and with visual function in children with ONH. Using OCT imaging, DD can be obtained in children with nystagmus and provides objective information.

Optical techniques for the study of living tissue

NARCIS (Netherlands)

Margallo Balbás, E.

2010-01-01

The potential of light in diagnosis and therapy has been long recognised. With the advent of scientific progress in our understanding of light propagation and interaction with tissue and parallel major technological advances in how optical energy can be generated, detected and processed, this

Microwave-optical double resonance spectroscopy. Progress report, February 1, 1978--January 31, 1979

Energy Technology Data Exchange (ETDEWEB)

Pratt, D.W.

1978-11-01

Optical, zero-field and high-field optical detection of magnetic resonance, electron-nuclear double resonance, level anticrossing and cross relaxation, and electron paramagnetic resonance experiments have been performed on a variety of chemical systems in order to further basic knowledge of the structure, reactivity, and response to radiation of molecules in their ground and/or excited electronic states. Systems investigated include organic molecules oriented in low temperature crystals, simple free radicals, transition metal complexes, rare earth hydrides, and hemeproteins in biological enzymes. Aside from their intrinsic interest, many of these systems are of potential importance in a number of applied areas including hydrocarbon-based fuel systems, solar energy devices, laser-initiated photochemical reactions, and free radical mechanisms in chemical carcinogenesis.

Microwave-optical double resonance spectroscopy. Progress report, February 1, 1978--January 31, 1979

International Nuclear Information System (INIS)

Pratt, D.W.

1978-01-01

Optical, zero-field and high-field optical detection of magnetic resonance, electron-nuclear double resonance, level anticrossing and cross relaxation, and electron paramagnetic resonance experiments have been performed on a variety of chemical systems in order to further basic knowledge of the structure, reactivity, and response to radiation of molecules in their ground and/or excited electronic states. Systems investigated include organic molecules oriented in low temperature crystals, simple free radicals, transition metal complexes, rare earth hydrides, and hemeproteins in biological enzymes. Aside from their intrinsic interest, many of these systems are of potential importance in a number of applied areas including hydrocarbon-based fuel systems, solar energy devices, laser-initiated photochemical reactions, and free radical mechanisms in chemical carcinogenesis

Heavy irradiation effects in radiation-resistant optical fibers

Energy Technology Data Exchange (ETDEWEB)

Shikama, Tatsuo [Tohoku Univ., Oarai, Ibaraki (Japan). Oarai Branch, Inst. for Materials Research

1998-07-01

Development of a system for optical measurements in a nuclear reactor has been progressing to investigate dynamic changes in a material caused by heavy irradiation. In such system, transfer of optical signals to out-pile measuring systems is being attempted by the use of optical fibers. In this report, the characteristics of optical fibers in the heavy irradiation field were summarized. It has been known that amorphous silica might produce radiolysis and structural defects by the exposure to ionizing radiation. The effects of heavy irradiation on molten silica were extremely complicated. A large intensity of visible light absorption occurred from an early time during start-up of the reactor. The absorption range was limited below 700 nm for the radiation associating fast neutron and the absorption was mostly attributed to non-bridging oxygen hole center. The depletion of optical transferring capacity under the radiation might be related to the internal stress. Therefore, it seems desirable to use optical fibers in the conditions without leading too much stress. (M.N.)

Primary Sjoegren's syndrome initially manifested by optic neuritis: MRI findings

International Nuclear Information System (INIS)

Kadota, Y.; Tokumaru, A.M.; Kohyama, S.; Okizuka, H.; Kaji, T.; Kusano, S.; Kamakura, K.

2002-01-01

We herein describe the MRI findings in a patient clinically diagnosed with primary Sjoegren's syndrome (SjS) initially manifested by retrobulbar optic neuritis. A 63-year-old woman suddenly had left ocular pain and progressive visual disturbance. MR T2-weighted images revealed hyperintensity in the left optic nerve, with swelling. Contrast-enhanced T1-weighted images showed no abnormal enhancement. Follow-up MRI 6 months after admission revealed no significant changes in the affected optic nerve. To our knowledge, optic neuritis as a complication of SjS has been reported in ten patients [1, 2, 3, 4, 5, 6] and MRI findings in only one of them [6]. We thought MR images were useful for visualizing optic nerve involvement in SjS and observing its course. (orig.)

Do shorter wavelengths improve contrast in optical mammography?

International Nuclear Information System (INIS)

Taroni, P; Pifferi, A; Torricelli, A; Spinelli, L; Danesini, G M; Cubeddu, R

2004-01-01

The detection of tumours with time-resolved transmittance imaging relies essentially on blood absorption. Previous theoretical and phantom studies have shown that both contrast and spatial resolution of optical images are affected by the optical properties of the background medium, and high absorption and scattering are generally beneficial. Based on these observations, wavelengths shorter than presently used (680-780 nm) could be profitable for optical mammography. A study was thus performed analysing time-resolved transmittance images at 637, 656, 683 and 785 nm obtained from 26 patients bearing 16 tumours and 15 cysts. The optical contrast proved to increase upon decreasing wavelengths for the detection of cancers in late-gated intensity images, with higher gain in contrast for lesions of smaller size (<1.5 cm diameter). For cysts either a progressive increase or decrease in contrast with wavelength was observed in scattering images

Snapshot polarization-sensitive plug-in optical module for a Fourier-domain optical coherence tomography system

Science.gov (United States)

Marques, Manuel J.; Rivet, Sylvain; Bradu, Adrian; Podoleanu, Adrian

2018-02-01

In this communication, we present a proof-of-concept polarization-sensitive Optical Coherence Tomography (PS-OCT) which can be used to characterize the retardance and the axis orientation of a linear birefringent sample. This module configuration is an improvement from our previous work1, 2 since it encodes the two polarization channels on the optical path difference, effectively carrying out the polarization measurements simultaneously (snapshot measurement), whilst retaining all the advantages (namely the insensitivity to environmental parameters when using SM fibers) of these two previous configurations. Further progress consists in employing Master Slave OCT technology,3 which is used to automatically compensate for the dispersion mismatch introduced by the elements in the module. This is essential given the encoding of the polarization states on two different optical path lengths, each of them having dissimilar dispersive properties. By utilizing this method instead of the commonly used re-linearization and numerical dispersion compensation methods an improvement in terms of the calculation time required can be achieved.

Progress in ultrafast intense laser science

CERN Document Server

Yamanouchi, Kaoru; Mathur, Deepak

2014-01-01

The PUILS series delivers up-to-date reviews of progress in Ultrafast Intense Laser Science, a newly emerging interdisciplinary research field spanning atomic and molecular physics, molecular science, and optical science, which has been stimulated by the recent developments in ultrafast laser technologies. Each volume compiles peer-reviewed articles authored by researchers at the forefront of each their own subfields of UILS. Every chapter opens with an overview of the topics to be discussed, so that researchers unfamiliar to the subfield, as well as graduate students, can grasp the importance

Evaluation of retinal nerve fiber layer thickness measurements using optical coherence tomography in patients with tobacco-alcohol-induced toxic optic neuropathy

Directory of Open Access Journals (Sweden)

Moura Frederico

2010-01-01

Full Text Available Three patients with progressive visual loss, chronic alcoholism and tabagism were submitted to a complete neuro-ophthalmic examination and to retinal nerve fiber layer (RNFL measurements using optical coherence tomography (OCT scanning. Two patients showed marked RNFL loss in the temporal sector of the optic disc. However, a third patient presented RNFL measurements within or above normal limits, based on the Stratus-OCT normative database. Such findings may be due to possible RNFL edema similar to the one that may occur in the acute phase of toxic optic neuropathies. Stratus-OCT was able to detect RNFL loss in the papillomacular bundle of patients with tobacco-alcohol-induced toxic optic neuropathy. However, interpretation must be careful when OCT does not show abnormality in order to prevent diagnostic confusion, since overestimation of RNFL thickness measurements is possible in such cases.

Ethambutol/Linezolid Toxic Optic Neuropathy.

Science.gov (United States)

Libershteyn, Yevgeniya

2016-02-01

To report a rare toxic optic neuropathy after long-term use of two medications: ethambutol and linezolid. A 65-year-old man presented to the Miami Veterans Affairs Medical Center in December 2014 for evaluation of progressive vision decrease in both eyes. The patient presented with best-corrected visual acuities of 20/400 in the right eye and counting fingers at 5 feet in the left eye. Color vision was significantly reduced in both eyes. Visual fields revealed a cecocentral defect in both eyes. His fundus and optic nerve examination was unremarkable. Because vision continued to decline after discontinuation of ethambutol, linezolid was also discontinued, after which vision, color vision, and visual fields improved. Because of these findings, the final diagnosis was toxic optic neuropathy. Final visual outcome was 20/30 in the right eye and 20/40 in the left eye. Drug-associated toxic optic neuropathy is a rare but vision-threatening condition. Diagnosis is made based on an extensive case history and careful clinical examination. The examination findings include varying decrease in vision, normal pupils and extraocular muscles, and unremarkable fundoscopy, with the possibility of swollen optic discs in the acute stage of the optic neuropathy. Other important findings descriptive of toxic optic neuropathy include decreased color vision and cecocentral visual field defects. This case illustrates the importance of knowledge of all medications and/or substances a patient consumes that may cause a toxic reaction and discontinuing them immediately if the visual functions are worsening or not improving.

The Particle Beam Optics Interactive Computer Laboratory

International Nuclear Information System (INIS)

Gillespie, G.H.; Hill, B.W.; Brown, N.A.; Babcock, R.C.; Martono, H.; Carey, D.C.

1997-01-01

The Particle Beam Optics Interactive Computer Laboratory (PBO Lab) is an educational software concept to aid students and professionals in learning about charged particle beams and particle beam optical systems. The PBO Lab is being developed as a cross-platform application and includes four key elements. The first is a graphic user interface shell that provides for a highly interactive learning session. The second is a knowledge database containing information on electric and magnetic optics transport elements. The knowledge database provides interactive tutorials on the fundamental physics of charged particle optics and on the technology used in particle optics hardware. The third element is a graphical construction kit that provides tools for students to interactively and visually construct optical beamlines. The final element is a set of charged particle optics computational engines that compute trajectories, transport beam envelopes, fit parameters to optical constraints and carry out similar calculations for the student designed beamlines. The primary computational engine is provided by the third-order TRANSPORT code. Augmenting TRANSPORT is the multiple ray tracing program TURTLE and a first-order matrix program that includes a space charge model and support for calculating single particle trajectories in the presence of the beam space charge. This paper describes progress on the development of the PBO Lab. copyright 1997 American Institute of Physics

Computed tomography in optic neuritis

International Nuclear Information System (INIS)

Fujitani, Ken; Hakuba, Akira; Tsujimoto, Takeshi; Yasui, Toshihiro; Sakamoto, Hiroaki

1979-01-01

In two patients with optic neuritis, CT scans showed common features which were helpful in diagnosis. These consisted of an enlargement of the optic nerve and an increased density of the optic nerve after contrast infusion. A 49-year-old man was admitted with a two-week duration of pain and a progressive visual loss in his right eye. On admission, an enlarged central scotoma was noted, and only a flashlight was perceived at the periphery in the right eye. The right optic disc was swollen with perivascular bleeding. Plain skull radiographs and orbital tomographs were normal. An orbital CT scan, however, revealed an enlargement of the right optic nerve, the density of which was increased after the infusion of a contrast medium. After steroid therapy, the CT scan showed a normal optic nerve following improvement in the vision of the right eye. A 44-year-old man was referred to this hospital because of a visual loss in his right eye which had been noted one month before. The right eye, with a central scotoma, had only visual acuity enough to perceive hand motion. The right pupil responded poorly to light. The right optic disc was hyperemic. Plain skull radiographs were normal. The orbital CT scan, however, showed an enlargement of the right optic nerve and exhibited contrast enhancement. Steroid therapy resulted in an improvement of the visual disturbance, and a follow-up CT scan showed normal. Two months later, though, the visual acuity had decreased and a visual field defect was noted in his left eye. The orbital CT scan revealed an enlargement of the left optic nerve. The administration of steroid again improved the visual field defect in the left eye, and the CT scan again showed normal. (author)

NATO Advanced Study Institute on Nano-Optics : Principles Enabling Basic Research and Applications

CERN Document Server

Collins, John; Silvestri, Luciano

2017-01-01

This book provides a comprehensive overview of nano-optics, including basic theory, experiment and applications, particularly in nanofabrication and optical characterization. The contributions clearly demonstrate how advances in nano-optics and photonics have stimulated progress in nanoscience and -fabrication, and vice versa. Their expert authors address topics such as three-dimensional optical lithography and microscopy beyond the Abbe diffraction limit, optical diagnostics and sensing, optical data- and telecommunications, energy-efficient lighting, and efficient solar energy conversion. Nano-optics emerges as a key enabling technology of the 21st century. This work will appeal to a wide readership, from physics through chemistry, to biology and engineering. The contributions that appear in this volume were presented at a NATO Advanced Study Institute held in Erice, 4-19 July, 2015.

Atomic physics and quantum optics using superconducting circuits.

Science.gov (United States)

You, J Q; Nori, Franco

2011-06-29

Superconducting circuits based on Josephson junctions exhibit macroscopic quantum coherence and can behave like artificial atoms. Recent technological advances have made it possible to implement atomic-physics and quantum-optics experiments on a chip using these artificial atoms. This Review presents a brief overview of the progress achieved so far in this rapidly advancing field. We not only discuss phenomena analogous to those in atomic physics and quantum optics with natural atoms, but also highlight those not occurring in natural atoms. In addition, we summarize several prospective directions in this emerging interdisciplinary field.

Progressive Decrease of Peripapillary Angioflow Vessel Density During Structural and Visual Field Progression in Early Primary Open-angle Glaucoma.

Science.gov (United States)

Holló, Gábor

2017-07-01

To present a case of early primary open-angle glaucoma in which retinal nerve fiber layer thickness (RNFLT), ganglion cell complex (GCC), and visual field progression were accompanied with significant progression of peripapillary angioflow vessel density (PAFD) measured with optical coherence tomographic angiography. A 68-year-old female patient who was under topical intraocular pressure (IOP) lowering medication for 20 years for ocular hypertension of the right and preperimetric primary open-angle glaucoma of the left eye (with reproducible inferotemporal and superotemporal neuroretinal rim and RNFL loss) was prospectively imaged with the AngioVue OCT for RNFLT, GCC thickness, and PAFD, and investigated with the Octopus Normal G2 visual field test on the same days at 6-month intervals for 18 months, while the IOP of the left eye escaped from control. IOP of the left eye fluctuated between 14 and 30 mm Hg in the study period. RNFLT, GCC thickness, and peripapillary PAFD all decreased significantly (linear regression analysis, P=0.030, 0.040, and 0.020, respectively), and a significant 2.1 dB/y progression was seen for a superior visual field cluster. The RNFLT, peripapillary PAFD, and visual field of the right eye remained normal and unchanged. In our case IOP elevation, glaucomatous visual field conversion, and structural progression were accompanied with significant progressive decrease of peripapillary PAFD. The simultaneous thinning of RNFLT and GCC and decrease of peripapillary PAFD suggest that PAFD may potentially be an additional indicator of early progression in primary open-angle glaucoma.

Chinese National Optical Education Small Private Online Course system

Science.gov (United States)

Zhang, XiaoJie; Lin, YuanFang; Liu, Xu; Liu, XiangDong; Cen, ZhaoFeng; Li, XiaoTong; Zheng, XiaoDong; Wang, XiaoPing

2017-08-01

In order to realize the sharing of high quality course resources and promote the deep integration of `Internet+' higher education and talent training, a new on-line to off-line specialized courses teaching mode was explored in Chinese colleges and universities, which emphasized different teaching places, being organized asynchronously and localized. The latest progress of the Chinese National Optical Education Small Private On-line Course (CNOESPOC) system set up by Zhejiang University and other colleges and universities having disciplines in the field of optics and photonics under the guidance of the Chinese National Steering Committee of Optics and Photonics (CNSCOP) was introduced in this paper. The On-line to Off-line (O2O) optical education teaching resource sharing practice offers a new good example for higher education in China under the background of Internet +.

Optical Access Networks

Science.gov (United States)

Zheng, Jun; Ansari, Nirwan

2005-06-01

are now underway this hot area. The purpose of this feature issue is to expose the networking community to the latest research breakthroughs and progresses in the area of optical access networks. This feature issue aims to present a collection of papers that focus on the state-of-the-art research in various networking aspects of optical access networks. Original papers are solicited from all researchers involved in area of optical access networks. Topics of interest include but not limited to: Optical access network architectures and protocols Passive optical networks (BPON, EPON, GPON, etc.) Active optical networks Multiple access control Multiservices and QoS provisioning Network survivability Field trials and standards Performance modeling and analysis

Progress on Chinese evaluated nuclear parameter library (CENPL) (II)

International Nuclear Information System (INIS)

Su Zhongdi; Ge Zhigang; Zhou Chunmei

1993-01-01

CENPL collected, evaluated and compiled nuclear basic constants and model parameters. CENPL-1 contain six sub-libraries, they are: (1) Atomic masses and characteristic constants for nuclear ground states; (2) discrete level schemes and branch ratios of γ decay; (3) level density parameters; (4) giant dipole resonance parameters for γ-ray strength function (5) fission barrier parameter; (6) optical model parameters. Their progresses are introduced

Spectral-domain optical coherence tomography staging and autofluorescence imaging in achromatopsia.

Science.gov (United States)

Greenberg, Jonathan P; Sherman, Jerome; Zweifel, Sandrine A; Chen, Royce W S; Duncker, Tobias; Kohl, Susanne; Baumann, Britta; Wissinger, Bernd; Yannuzzi, Lawrence A; Tsang, Stephen H

2014-04-01

IMPORTANCE Evidence is mounting that achromatopsia is a progressive retinal degeneration, and treatments for this condition are on the horizon. OBJECTIVES To categorize achromatopsia into clinically identifiable stages using spectral-domain optical coherence tomography and to describe fundus autofluorescence imaging in this condition. DESIGN, SETTING, AND PARTICIPANTS A prospective observational study was performed between 2010 and 2012 at the Edward S. Harkness Eye Institute, New York-Presbyterian Hospital. Participants included 17 patients (aged 10-62 years) with full-field electroretinography-confirmed achromatopsia. MAIN OUTCOMES AND MEASURES Spectral-domain optical coherence tomography features and staging system, fundus autofluorescence and near-infrared reflectance features and their correlation to optical coherence tomography, and genetic mutations served as the outcomes and measures. RESULTS Achromatopsia was categorized into 5 stages on spectral-domain optical coherence tomography: stage 1 (2 patients [12%]), intact outer retina; stage 2 (2 patients [12%]), inner segment ellipsoid line disruption; stage 3 (5 patients [29%]), presence of an optically empty space; stage 4 (5 patients [29%]), optically empty space with partial retinal pigment epithelium disruption; and stage 5 (3 patients [18%]), complete retinal pigment epithelium disruption and/or loss of the outer nuclear layer. Stage 1 patients showed isolated hyperreflectivity of the external limiting membrane in the fovea, and the external limiting membrane was hyperreflective above each optically empty space. On near infrared reflectance imaging, the fovea was normal, hyporeflective, or showed both hyporeflective and hyperreflective features. All patients demonstrated autofluorescence abnormalities in the fovea and/or parafovea: 9 participants (53%) had reduced or absent autofluorescence surrounded by increased autofluorescence, 4 individuals (24%) showed only reduced or absent autofluorescence, 3

Reconfigurable optical implementation of quantum complex networks

Science.gov (United States)

Nokkala, J.; Arzani, F.; Galve, F.; Zambrini, R.; Maniscalco, S.; Piilo, J.; Treps, N.; Parigi, V.

2018-05-01

Network theory has played a dominant role in understanding the structure of complex systems and their dynamics. Recently, quantum complex networks, i.e. collections of quantum systems arranged in a non-regular topology, have been theoretically explored leading to significant progress in a multitude of diverse contexts including, e.g., quantum transport, open quantum systems, quantum communication, extreme violation of local realism, and quantum gravity theories. Despite important progress in several quantum platforms, the implementation of complex networks with arbitrary topology in quantum experiments is still a demanding task, especially if we require both a significant size of the network and the capability of generating arbitrary topology—from regular to any kind of non-trivial structure—in a single setup. Here we propose an all optical and reconfigurable implementation of quantum complex networks. The experimental proposal is based on optical frequency combs, parametric processes, pulse shaping and multimode measurements allowing the arbitrary control of the number of the nodes (optical modes) and topology of the links (interactions between the modes) within the network. Moreover, we also show how to simulate quantum dynamics within the network combined with the ability to address its individual nodes. To demonstrate the versatility of these features, we discuss the implementation of two recently proposed probing techniques for quantum complex networks and structured environments.

Nonlinear Pulse Shaping in Fibres for Pulse Generation and Optical Processing

Directory of Open Access Journals (Sweden)

Sonia Boscolo

2012-01-01

Full Text Available The development of new all-optical technologies for data processing and signal manipulation is a field of growing importance with a strong potential for numerous applications in diverse areas of modern science. Nonlinear phenomena occurring in optical fibres have many attractive features and great, but not yet fully explored, potential in signal processing. Here, we review recent progress on the use of fibre nonlinearities for the generation and shaping of optical pulses and on the applications of advanced pulse shapes in all-optical signal processing. Amongst other topics, we will discuss ultrahigh repetition rate pulse sources, the generation of parabolic shaped pulses in active and passive fibres, the generation of pulses with triangular temporal profiles, and coherent supercontinuum sources. The signal processing applications will span optical regeneration, linear distortion compensation, optical decision at the receiver in optical communication systems, spectral and temporal signal doubling, and frequency conversion.

Progress of radiation curing technology and its industrial applications in Japan

International Nuclear Information System (INIS)

Takashi Ukachi

2007-01-01

The Japanese industry has grown with annual growth rate 108%. Electric parts and devices industry strongly promoted Japanese economy. UV/EB curing market in Japan enjoyed its steady growth with an annual growth rate 107%. By realizing the advantages of good performance and high functionality, the UV/EB curing technology has expanded its application field especially in leading edge industries, such as electric parts and devices, FPDs, Optical fibers and cables, optical recording media, and their fabrication and manufacturing. This paper summarizes the Japanese UV/EB market situation and overviews the latest progress of UV/EB technology. (Author)

Optical Magnetometry Using Multiphoton Transitions

Science.gov (United States)

Degenkolb, Skyler M.

Optical magnetometry plays a critical role in low-energy precision measurements and numerous other applications. In particular, permanent electric dipole moment (EDM) searches impose strict requirements on magnetic field sensitivity of the underlying atomic or molecular species. Other magnetometer properties - such as chemical reactivity, dielectric strength, and interaction cross-sections with other species - also impose limitations on experimental conditions. Here, we explore a novel approach to optical magnetometry, using multiphoton transitions of diamagnetic atoms to detect Larmor precession of polarized nuclei. Resonant probes are possible at moderate ultraviolet wavelengths, and hyperfine structure couples spin precession to fluorescence transitions with negligible backgrounds; paramagnetic rotation due to intensity-dependent dispersion may also be detectable. Nuclear spins and nonlinear optical excitation introduce new degrees of freedom, and evade limitations arising from rapid electronic decoherence. This dissertation reports progress towards two-photon optical magnetometry using ytterbium, rubidium, and xenon. We characterize the influence of probe polarization and magnetic fields on fluorescence spectra, for one- and two-photon continuous-wave (cw) excitation of ytterbium. Resolved hyperfine and isotope structure allow us to use spin-zero isotopes for diagnostics and normalization, and we develop analysis for overlapping two-photon resonances. We also report measurements of two-photon excitation in ytterbium and rubidium using picosecond laser pulses, and in xenon using a cw laser. Although hyperfine structure is unresolved, the rubidium measurements are sensitive to probe field polarization. Fluorescence spectra from two-photon excitation of ytterbium with femtosecond pulses show modulation when the repetition rate changes. Although techniques for polarizing noble gas nuclei are mature, existing cell designs are incompatible with two

Progress in Molecular Imaging in Endoscopy and Endomicroscopy for Cancer Imaging

Directory of Open Access Journals (Sweden)

Supang Khondee

2013-01-01

Full Text Available Imaging is an essential tool for effective cancer management. Endoscopes are important medical instruments for performing in vivo imaging in hollow organs. Early detection of cancer can be achieved with surveillance using endoscopy, and has been shown to reduce mortality and to improve outcomes. Recently, great advancements have been made in endoscopic instruments, including new developments in optical designs, light sources, optical fibers, miniature scanners, and multimodal systems, allowing for improved resolution, greater tissue penetration, and multispectral imaging. In addition, progress has been made in the development of highly-specific optical probes, allowing for improved specificity for molecular targets. Integration of these new endoscopic instruments with molecular probes provides a unique opportunity for significantly improving patient outcomes and has potential to further improve early detection, image guided therapy, targeted therapy, and personalized medicine. This work summarizes current and evolving endoscopic technologies, and provides an overview of various promising optical molecular probes.

Isolan - A Fibre Optic Network Conforming To IEEE 802.3 Standards

Science.gov (United States)

Roworth, D. A. A.; Howe, N.

1986-10-01

The progress of the IEEE 802.3 standard for fibre optic LANs is indicated with reference to both mixed media networks and full fibre networks. For a fibre optic network the most suitable layout is a "snowflake" topology composed of multiport repeaters and active fibre hubs. A range of components is described which enables the realisation of such a topology in conformance with the IEEE 802.3 standard.

The Art of Optical Aberrations

Science.gov (United States)

Wylde, Clarissa Eileen Kenney

Art and optics are inseparable. Though seemingly opposite disciplines, the combination of art and optics has significantly impacted both culture and science as they are now known. As history has run its course, in the sciences, arts, and their fruitful combinations, optical aberrations have proved to be a problematic hindrance to progress. In an effort to eradicate aberrations the simple beauty of these aberrational forms has been labeled as undesirable and discarded. Here, rather than approach aberrations as erroneous, these beautiful forms are elevated to be the photographic subject in a new body of work, On the Bright Side. Though many recording methods could be utilized, this work was composed on classic, medium-format, photographic film using white-light, Michelson interferometry. The resulting images are both a representation of the true light rays that interacted on the distorted mirror surfaces (data) and the artist's compositional eye for what parts of the interferogram are chosen and displayed. A detailed description of the captivating interdisciplinary procedure is documented and presented alongside the final artwork, CCD digital reference images, and deformable mirror contour maps. This alluring marriage between the arts and sciences opens up a heretofore minimally explored aspect of the inextricable art-optics connection. It additionally provides a fascinating new conversation on the importance of light and optics in photographic composition.

Progress of pancreatitis disease biomarker alpha amylase enzyme by new nano optical sensor.

Science.gov (United States)

Attia, M S; Al-Radadi, Najlaa S

2016-12-15

A new nano optical sensor binuclear Pd-(2-aminothiazole) (urea), Pd(atz,ur) complex was prepared and characterized for the assessment of the activity of alpha amylase enzyme in urine and serum samples for early diagnosis of Pancreatitis disease. The assessment of alpha amylase activity is carried out by the quenching of the luminescence intensity of the nano optical sensor binuclear Pd(atz,ur) complex at 457nm by the 2-chloro-4-nitrophenol (2-CNP) which produced from the reaction of the enzyme with 2-chloro-4-nitrophenyl-α-d-maltotrioside (CNPG3) substrate. The remarkable quenching of the luminescence intensity at 457nm of nano Pd(atz,ur) doped in sol-gel matrix by various concentrations of the 2-CNP was successfully used as an optical sensor for the assessment of α-amylase activity. The calibration plot was achieved over the concentration range 8.5×10(-6) to 1.9×10(-9)molL(-1) 2-CNP with a correlation coefficient of (0.999) and a detection limit of (7.4×10(-10)molL(-1)). The method was used satisfactorily for the assessment of the α-amylase activity over activity range (3-321U/L) in different urine and serum samples of pancreatitis patients. The assessment of the alpha amylase biomarker by the proposed method increases its sensitivity (96.88%) and specificity (94.41%) for early diagnosis of pancreatitis diseases. Copyright © 2016 Elsevier B.V. All rights reserved.

Optical spectroscopy of an atomic nucleus: Progress toward direct observation of the {sup 229}Th isomer transition

Energy Technology Data Exchange (ETDEWEB)

Hehlen, Markus P., E-mail: hehlen@lanl.gov [Los Alamos National Laboratory, Mailstop E549, Los Alamos, NM 87545 (United States); Greco, Richard R. [Los Alamos National Laboratory, Mailstop E549, Los Alamos, NM 87545 (United States); Rellergert, Wade G.; Sullivan, Scott T. [Department of Physics and Astronomy, University of California, Los Angeles, CA 90095 (United States); DeMille, David [Department of Physics, Yale University, New Haven, CT 06511 (United States); Jackson, Robert A. [School of Physical and Geographical Sciences, Keele University, Keele, Staffordshire ST5 5BG (United Kingdom); Hudson, Eric R. [Department of Physics and Astronomy, University of California, Los Angeles, CA 90095 (United States); Torgerson, Justin R. [Los Alamos National Laboratory, Mailstop E549, Los Alamos, NM 87545 (United States)

2013-01-15

The nucleus of the thorium-229 isotope possesses a first excited nuclear state ({sup 229m}Th) at an exceptionally low energy of 7.8{+-}0.5 eV above the nuclear ground state ({sup 229g}Th), as determined by earlier indirect measurements. This is the only nuclear excited state known that is within the range of optical spectroscopy. This paper reports progress toward detecting the {sup 229m}Th state directly by luminescence spectroscopy in the vacuum ultraviolet spectral region. The estimated natural linewidth of the {sup 229g}Th{r_reversible}{sup 229m}Th isomer transition of 2{pi} Multiplication-Sign 0.1 to 2{pi} Multiplication-Sign 10 mHz is expected to broaden to {approx}10 kHz for {sup 229}Th{sup 4+} doped into a suitable crystal. The factors governing the choice of crystal system and the substantial challenges in acquiring a sufficiently large quantity of {sup 229}Th are discussed. We show that the {sup 229g}Th{r_reversible}{sup 229m}Th transition energy can be identified to within 0.1 nm by luminescence excitation and luminescence spectroscopy using the Advanced Light Source (ALS) at Lawrence Berkeley National Laboratory. This would open the door for subsequent laser-based measurements of the isomer transition and future applications of {sup 229}Th in nuclear clocks. We also show that {sup 233}U-doped materials should produce an intrinsic, continuous, and sufficiently high rate of {sup 229m}Th{yields}{sup 229g}Th luminescence and could be a useful aid in the initial direct search of the isomer transition. - Highlights: Black-Right-Pointing-Pointer Thorium-229 has a long-lived nuclear excited state. Black-Right-Pointing-Pointer It is the only known nuclear isomer within the reach of optical spectroscopy. Black-Right-Pointing-Pointer Thorium-229 doped fluoride crystals may offer sufficiently high luminescence rates. Black-Right-Pointing-Pointer Luminescence excitation spectroscopy in the vacuum ultraviolet spectral region may enable the first direct observation of

Risk of progression in macula-on rhegmatogenous retinal detachment.

Science.gov (United States)

Callizo, Josep; Pfeiffer, Sebastian; Lahme, Eva; van Oterendorp, Christian; Khattab, Mohammed; Bemme, Sebastian; Kulanga, Miroslav; Hoerauf, Hans; Feltgen, Nicolas

2017-08-01

To identify factors that may lead to a rapid progression in macula-on rhegmatogenous retinal detachment (RRD), in particular, those that may lead to macular involvement. Observational, prospective, single-center study. Patients referred for surgery due to primary rhegmatogenous retinal detachment with the macula on between 2009 and 2013 were included. Relevant factors analyzed included age, time delay until surgery, lens status, myopia, the detachment's location and configuration as well as number, size and type of retinal breaks. Eyes underwent optical coherence tomography to detect macular detachment. A multivariate analysis was performed to investigate the effect of several factors in the progression of retinal detachment. A total of 116 eyes of 116 patients were included. Mean time delay between admission and surgery was 1.8 ± 1.4 days. Progression was observed in 19.8% of the eyes. Of those, 47.8% presented macular detachment. Ten of the 11 (90.9%) eyes presenting progression involving the macula also exhibited a bullous configuration, which was the only parameter that correlated significantly with detachment progression in patients with (p = 0.0036) and without (p = 0.0014) macular involvement. For the first time in a prospective trial, a bullous configuration was found to be a highly significant predictor for progression in macula-on detachments. Our data support prompt surgery in patients diagnosed with bullous macula-on RRD.

Differential Deposition for Surface Figure Corrections in Grazing Incidence X-Ray Optics

Science.gov (United States)

Ramsey, Brian D.; Kilaru, Kiranmayee; Atkins, Carolyn; Gubarev, Mikhail V.; Broadway, David M.

2015-01-01

Differential deposition corrects the low- and mid- spatial-frequency deviations in the axial figure of Wolter-type grazing incidence X-ray optics. Figure deviations is one of the major contributors to the achievable angular resolution. Minimizing figure errors can significantly improve the imaging quality of X-ray optics. Material of varying thickness is selectively deposited, using DC magnetron sputtering, along the length of optic to minimize figure deviations. Custom vacuum chambers are built that can incorporate full-shell and segmented Xray optics. Metrology data of preliminary corrections on a single meridian of full-shell x-ray optics show an improvement of mid-spatial frequencies from 6.7 to 1.8 arc secs HPD. Efforts are in progress to correct a full-shell and segmented optics and to verify angular-resolution improvement with X-ray testing.

Recent Progress in Syntheses and Applications of Dumbbell-like Nanoparticles**

OpenAIRE

Wang, Chao; Xu, Chenjie; Zeng, Hao; Sun, Shouheng

2009-01-01

This paper reviews the recent research progress in syntheses and applications of dumbbell-like nanoparticles. It first describes the general synthesis of dumbbell-like nanoparticles containing noble metal and magnetic NPs/or quantum dots. It then outlines the interesting optical and magnetic properties found in these dumbbell nanoparticles. The review further highlights several exciting application potentials of these nanoparticles in catalysis and biomedicine.

Polymeric nanoparticles for optical sensing.

Science.gov (United States)

Canfarotta, Francesco; Whitcombe, Michael J; Piletsky, Sergey A

2013-12-01

Nanotechnology is a powerful tool for use in diagnostic applications. For these purposes a variety of functional nanoparticles containing fluorescent labels, gold and quantum dots at their cores have been produced, with the aim of enhanced sensitivity and multiplexing capabilities. This work will review progress in the application of polymeric nanoparticles in optical diagnostics, both for in vitro and in vivo detection, together with a discussion of their biodistribution and biocompatibility. © 2013.

Fiber Optic Surface Plasmon Resonance-Based Biosensor Technique: Fabrication, Advancement, and Application.

Science.gov (United States)

Liang, Gaoling; Luo, Zewei; Liu, Kunping; Wang, Yimin; Dai, Jianxiong; Duan, Yixiang

2016-05-03

Fiber optic-based biosensors with surface plasmon resonance (SPR) technology are advanced label-free optical biosensing methods. They have brought tremendous progress in the sensing of various chemical and biological species. This review summarizes four sensing configurations (prism, grating, waveguide, and fiber optic) with two ways, attenuated total reflection (ATR) and diffraction, to excite the surface plasmons. Meanwhile, the designs of different probes (U-bent, tapered, and other probes) are also described. Finally, four major types of biosensors, immunosensor, DNA biosensor, enzyme biosensor, and living cell biosensor, are discussed in detail for their sensing principles and applications. Future prospects of fiber optic-based SPR sensor technology are discussed.

Progress on the occulter experiment at Princeton

Science.gov (United States)

Cady, Eric; Balasubramanian, Kunjithapatham; Carr, Michael; Dickie, Matthew; Echternach, Pierre; Groff, Tyler; Kasdin, Jeremy; Laftchiev, Christian; McElwain, Michael; Sirbu, Dan; Vanderbei, Robert; White, Victor

2009-08-01

An occulter is used in conjunction with a separate telescope to suppress the light of a distant star. To demonstrate the performance of this system, we are building an occulter experiment in the laboratory at Princeton. This experiment will use an etched silicon mask as the occulter, with some modifications to try to improve the performance. The occulter is illuminated by a diverging laser beam to reduce the aberrations from the optics before the occulter. We present the progress of this experiment and expectations for future work.

Research program in elementary particle theory. Progress report, 1984

International Nuclear Information System (INIS)

Sudarshan, E.C.G.; Dicus, D.A.

1984-04-01

Research progress is reported on the following topics: gauge theory and monopole physics; supersymmetry and proton decay; strong interactions and model of particles; quantum rotator and spectrum generating group models of particles; geometric foundations of particle physics and optics; and application of particle physics to astrophysics. The titles of DOE reports are listed, and research histories of the scientific staff of the Center for Particle Theory are included

Recent progress in organic electronics and photonics: A perspective on the future of organic devices

KAUST Repository

Bredas, Jean-Luc

2016-02-25

The fields of organic electronics and photonics have witnessed remarkable advances over the past few years. This progress bodes well for the increased utilization of organic materials as the active layers in devices for applications as diverse as light-emitting diodes, field-effect transistors, solar cells, or all-optical switches. In the present document, we choose to focus the discussion on organic all-optical switching applications. © 2015 The Japan Society of Applied Physics.

Optic Nerve Sheath Meningocele: A Case Report

Science.gov (United States)

Halimi, E.; Wavreille, O.; Rosenberg, R.; Bouacha, I.; Lejeune, J.-P.; Defoort-Dhellemmes, S.

2013-01-01

Abstract Isolated optic nerve sheath meningocele is a rare affection defined as the cystic enlargement of the optic nerve sheath filled with cerebrospinal fluid. We report the case of a 39-year-old woman presenting with bilateral meningocele uncovered during a routine examination for headache complaints. A 5-year follow-up validated the lesion’s clinical and imaging stability. Magnetic resonance imaging (MRI) is an essential tool in the diagnosis of this pathology, alongside characteristic symptoms indicating that the meningocele might have progressively expanded into the orbit. In this case we present a therapeutic approach based on pathophysiological hypotheses and review of the literature. PMID:28163760

Anomalous diffusion in a dynamical optical lattice

Science.gov (United States)

Zheng, Wei; Cooper, Nigel R.

2018-02-01

Motivated by experimental progress in strongly coupled atom-photon systems in optical cavities, we study theoretically the quantum dynamics of atoms coupled to a one-dimensional dynamical optical lattice. The dynamical lattice is chosen to have a period that is incommensurate with that of an underlying static lattice, leading to a dynamical version of the Aubry-André model which can cause localization of single-particle wave functions. We show that atomic wave packets in this dynamical lattice generically spread via anomalous diffusion, which can be tuned between superdiffusive and subdiffusive regimes. This anomalous diffusion arises from an interplay between Anderson localization and quantum fluctuations of the cavity field.

55th electric science promotion prize (progress prize). Demonstration of optical soliton transmission on OPGW first in the world; Dai 55 kai denki gakujutsu shinkosho (shinposho) jusho. Seiaihatsu no OPGW ni okeru hikari soriton denso no jissho

Energy Technology Data Exchange (ETDEWEB)

NONE

1999-06-10

Electric science promotion prize (progress prize) is given to `Person who newly proposed a new concept, theory, material, device, system and method on electrical science and technology, or demonstrated these proposals` by the commendation committee of Institute of Electrical Engineers of Japan every year. Eight promotion prizes including that for Kansai Electric Power`s `Demonstration of optical soliton transmission on OPGW first in the world` were given. This research succeeded in development of the transmission/ receiving device suitable for optical soliton transmission, and the prediction method of an optimum transmission condition by computer simulation. In addition, this research succeeded in 10Gbit transmission of 784km and 40Gbit transmission (4-wave multiplex) of 392km by applying the above research result to Okurobe trunk line OPGW (98.2km). This demonstration of optical soliton transmission on OPGW is first in the world. (NEDO)

Optic axis-driven new horizons for hyperbolic metamaterials

Directory of Open Access Journals (Sweden)

Boardman Allan D.

2015-01-01

Full Text Available The broad assertion here is that the current hyperbolic metamaterial world is only partially served by investigations that incorporate only some limited version of anisotropy. Even modest deviations of the optic axis from the main propagation axis lead to new phase shifts, which not only compete with those created by absorption but end up dominating them. Some progress has been attempted in the literature by introducing the terms “asymmetric hyperbolic media”, but it appears that this kind of asymmetry only involves an optic axis at an angle to the interface of a uniaxial crystal. From a device point of view, many new prospects should appear and the outcomes of the investigations presented here yield a new general theory. It is emphasised that the orientation of the optic axis is a significant determinant in the resulting optical properties. Whereas for conventional anisotropic waveguides homogeneous propagating waves occur over a limited range of angular dispositions of the optic axis it is shown that for a hyperbolic guide a critical angular setting exists, above which the guided waves are always homogeneous. This has significant implications for metawaveguide designs. The resulting structures are more tolerant to optic axis misalignment.

Mach-Zehnder atom interferometer inside an optical fiber

Science.gov (United States)

Xin, Mingjie; Leong, Wuiseng; Chen, Zilong; Lan, Shau-Yu

2017-04-01

Precision measurement with light-pulse grating atom interferometry in free space have been used in the study of fundamental physics and applications in inertial sensing. Recent development of photonic band-gap fibers allows light for traveling in hollow region while preserving its fundamental Gaussian mode. The fibers could provide a very promising platform to transfer cold atoms. Optically guided matter waves inside a hollow-core photonic band-gap fiber can mitigate diffraction limit problem and has the potential to bring research in the field of atomic sensing and precision measurement to the next level of compactness and accuracy. Here, we will show our experimental progress towards an atom interferometer in optical fibers. We designed an atom trapping scheme inside a hollow-core photonic band-gap fiber to create an optical guided matter waves system, and studied the coherence properties of Rubidium atoms in this optical guided system. We also demonstrate a Mach-Zehnder atom interferometer in the optical waveguide. This interferometer is promising for precision measurements and designs of mobile atomic sensors.

Optical mapping of optogenetically shaped cardiac action potentials

Science.gov (United States)

Park, Sarah A.; Lee, Shin-Rong; Tung, Leslie; Yue, David T.

2014-01-01

Light-mediated silencing and stimulation of cardiac excitability, an important complement to electrical stimulation, promises important discoveries and therapies. To date, cardiac optogenetics has been studied with patch-clamp, multielectrode arrays, video microscopy, and an all-optical system measuring calcium transients. The future lies in achieving simultaneous optical acquisition of excitability signals and optogenetic control, both with high spatio-temporal resolution. Here, we make progress by combining optical mapping of action potentials with concurrent activation of channelrhodopsin-2 (ChR2) or halorhodopsin (eNpHR3.0), via an all-optical system applied to monolayers of neonatal rat ventricular myocytes (NRVM). Additionally, we explore the capability of ChR2 and eNpHR3.0 to shape action-potential waveforms, potentially aiding the study of short/long QT syndromes that result from abnormal changes in action potential duration (APD). These results show the promise of an all-optical system to acquire action potentials with precise temporal optogenetics control, achieving a long-sought flexibility beyond the means of conventional electrical stimulation. PMID:25135113

Spectroscopy, Manipulation and Trapping of Neutral Atoms, Molecules, and Other Particles Using Optical Nanofibers: A Review

Science.gov (United States)

Morrissey, Michael J.; Deasy, Kieran; Frawley, Mary; Kumar, Ravi; Prel, Eugen; Russell, Laura; Truong, Viet Giang; Chormaic, Síle Nic

2013-01-01

The use of tapered optical fibers, i.e., optical nanofibers, for spectroscopy and the detection of small numbers of particles, such as neutral atoms or molecules, has been gaining interest in recent years. In this review, we briefly introduce the optical nanofiber, its fabrication, and optical mode propagation within. We discuss recent progress on the integration of optical nanofibers into laser-cooled atom and vapor systems, paying particular attention to spectroscopy, cold atom cloud characterization, and optical trapping schemes. Next, a natural extension of this work to molecules is introduced. Finally, we consider several alternatives to optical nanofibers that display some advantages for specific applications. PMID:23945738

Progress towards a small-scale, automated optical thin-film production capability

International Nuclear Information System (INIS)

Drage, D.J.; Netterfield, R.P.; Dligatch, S.; Blenman, N.; Fairman, P.S.; Katsaros, A.; Preston, E.W.

2000-01-01

Full text: The Optical Thin-film group at CSIRO Telecommunications and Industrial Physics (CTIP) has, working over a number of years, built up considerable expertise in producing complex dielectric, multilayer thin-film designs to meet unusual and demanding optical performance specifications. At the same time the process of vacuum deposition of dielectric materials has been advanced, particularly by the development and use of ion-assisted deposition (IAD). Proposed modifications to our existing chamber (DB600) and the addition of a new, larger diameter chamber (DD750), presently under construction, will increase output and reliability while improving quality. We will describe the changes already made to the DB600 such as: the gridless ion source, in-situ ellipsometric monitoring along with spectrophotometric monitoring, full e-beam scan on the material source, complete source shuttering and reactive deposition of SiO 2 from thermally evaporated SiO. The effects of making these beneficial changes will be described. Further changes to be made to the DB600 include, replacing its diffusion pump with a cryo-pump and automatic control of the deposition process. All the changes described for the DB600 along with a positive drive system for rotation of the substrate holder, rod feed e-gun hearths, and multiple crystal monitor heads, will be included in the DD750 design which will also be described. We believe that these improvements will give us the capability of small-scale production of reproducible, high quality filters

European Extremely Large Telescope: progress report

Science.gov (United States)

Tamai, R.; Spyromilio, J.

2014-07-01

The European Extremely Large Telescope is a project of the European Southern Observatory to build and operate a 40-m class optical near-infrared telescope. The telescope design effort is largely concluded and construction contracts are being placed with industry and academic/research institutes for the various components. The siting of the telescope in Northern Chile close to the Paranal site allows for an integrated operation of the facility providing significant economies. The progress of the project in various areas is presented in this paper and references to other papers at this SPIE meeting are made.

Neurosyphilis Presenting as Asymptomatic Optic Perineuritis

Directory of Open Access Journals (Sweden)

Sarah E. Parker

2012-01-01

Full Text Available Introduction. Syphilis is a sexually transmitted disease that is known as “the great imitator” due to its wide variety of clinical presentations, including ocular disorders. There has been an increase in the rate of syphilis in the United States, especially in persons with HIV. We report a case of optic perineuritis in an asymptomatic male secondary to central nervous system (CNS syphilis. Case Report. A 41-year-old man was found to have bilateral disc edema on a routine exam. Brain MRI was unremarkable, and lumbar puncture revealed a normal opening pressure, with an elevated cerebrospinal fluid white cell count. Orbit MRI showed optic nerve sheath expansion and enhancement, consistent with optic perineuritis. He tested positive for syphilis based on serum RPR and FTA-ABS. Conclusion. Ophthalmologic findings, including disc edema, may be the presenting features of CNS syphilis. Even in asymptomatic persons, perineuritis should be considered early, as diagnosis and treatment are imperative given the progressive nature of the disease.

Communication of nuclear data progress: No.7 (1992)

International Nuclear Information System (INIS)

1992-06-01

This is the seventh issue of communication of Nuclear Data Progress (CNDP), in which the nuclear data progress in china during the last year is presented. It includes 14 MeV neutron activation cross section nuclear decay data inelastic angular distribution integral prompt spontaneous fission neutron spectrum and α spectrum measurements of reaction 40 Ca(n, α); programs UNF-for fast neutron data calculation of structural materials, APCOM and APOM for searching optimal charged particle and neutron optical potential parameters respectively; P + 63 Cu reaction calculation in energy region 3 ∼ 55 MeV; evaluation of 197 Au (n, Zn) 196 Au cross section, progress on nuclear structure and decay data evaluation for A-chain a database on ion-atom collision processes, and evaluation of trapping and desorption data, systematics calculation of nuclear data for radiation damage assessment and related safety aspects, and systematics of (n, t) and (n, 3 He) reaction cross sections at 14 MeV, construction of covariance matrix for experimental data, Spline fit for multi-sets of correlative data etc

Structurally integrated fiber optic damage assessment system for composite materials.

Science.gov (United States)

Measures, R M; Glossop, N D; Lymer, J; Leblanc, M; West, J; Dubois, S; Tsaw, W; Tennyson, R C

1989-07-01

Progress toward the development of a fiber optic damage assessment system for composite materials is reported. This system, based on the fracture of embedded optical fibers, has been characterized with respect to the orientation and location of the optical fibers in the composite. Together with a special treatment, these parameters have been tailored to yield a system capable of detecting the threshold of damage for various impacted Kevlar/epoxy panels. The technique has been extended to measure the growth of a damage region which could arise from either impact, manufacturing flaws, or static overloading. The mechanism of optical fiber fracture has also been investigated. In addition, the influence of embedded optical fibers on the tensile and compressive strength of the composite material has been studied. Image enhanced backlighting has been shown to be a powerful and convenient method of assessing internal damage to translucent composite materials.

Long-term evolution of superficial optic disc drusen

DEFF Research Database (Denmark)

Larsen, Lasse Malmqvist; Lund-Andersen, Henrik; Hamann, Steffen

2017-01-01

with hereditary ODD were included. Results: Mean age at initial and follow-up examination was, respectively, 16.8 and 73.3 years. The median follow-up time was 56 years. A minimal or non-existing change in superficial ODD anatomy (size and number) was seen in 10 of 12 eyes. There was a tendency towards more......Purpose: Optic disc drusen (ODD) is hyaline deposits in the optic nerve head seen in 1-2% of the population. Long-term evolution of ODD anatomy and visual field defects in ODD patients is a key factor for learning more about pathophysiology and prognosis of the condition. With a median follow......-up period of 56 years, this is the first study that evaluates superficial optic disc anatomy and visual fields in patients with ODD over a life span. Methods: Observational case series investigating progression of superficial optic disc anatomy and visual fields in ODD patients. Eight patients...

Committee on Atomic, Molecular, and Optical Sciences (CAMOS)

International Nuclear Information System (INIS)

1992-01-01

The Committee on Atomic, Molecular and Optical Sciences (CAMOS) of the National Research Council (NRC) is charged with monitoring the health of the field of atomic, molecular, and optical (AMO) science in the United States. Accordingly, the Committee identifies and examines both broad and specific issues affecting the field. Regular meetings, teleconferences, briefings from agencies and the scientific community, the formation of study panels to prepare reports, and special symposia are among the mechanisms used by the CAMOS to meet its charge. This progress report presents a review of CAMOS activities from February 1, 1992 to January 31, 1993. This report also includes the status of activities associated with the CAMOS study on the field that is being conducted by the Panel on the Future of Atomic, Molecular, and Optical Sciences (FAMOS)

Optical Network Testbeds Workshop

Energy Technology Data Exchange (ETDEWEB)

Joe Mambretti

2007-06-01

technologies. Several years ago, when many of these optical networking research topics were first being investigated, they were the subject of controversial debate. The new techniques challenged many long-held concepts related to architecture and technology. However, today all major networking organizations are transitioning toward infrastructure that incorporates these new concepts. This progress has been assisted through the series of Optical Networking Testbed Workshops (ONT). The first (ONT1) outlined a general framework of key issues and topics and developed a series of recommendations (www.nren.nasa.gov/workshop7). The second (ONT2) developed a common vision of optical network technologies, services, infrastructure, and organizations (www.nren.nasa.gov/workshop8). Processes that allow for a common vision encourage widespread deployment of these types of resources among advanced networking communities. Also, such a shared vision enables key concepts and technologies to migrate from basic research testbeds to wider networking communities. The ONT-3 workshop built on these earlier activities by expanding discussion to include additional considerations of the international interoperability and of greater impact of optical networking technology on networking in general. In accordance with this recognition, the workshop confirmed that future-oriented research and development is indispensable to fundamentally change the current Internet architecture to create a global network incorporating completely new concepts. The workshop also recognized that the first priority to allow for this progress is basic research and development, including international collaborative activities, which are important for the global realization of interoperability of a new generation architecture.

Progress in ultrafast intense laser science XI

CERN Document Server

Yamanouchi, Kaoru; Martin, Philippe

2014-01-01

The PUILS series delivers up-to-date reviews of progress in Ultrafast Intense Laser Science, a newly emerging interdisciplinary research field spanning atomic and molecular physics, molecular science and optical science, which has been stimulated by the recent developments in ultrafast laser technologies. Each volume compiles peer-reviewed articles authored by researchers at the forefront of each their own subfields of UILS. Every chapter opens with an overview of the topics to be discussed, so that researchers unfamiliar to the subfield, as well as graduate students, can grasp the importance

Progress in Ultrafast Intense Laser Science II

CERN Document Server

Yamanouchi, Kaoru; Agostini, Pierre; Ferrante, Gaetano

2007-01-01

This book series addresses a newly emerging interdisciplinary research field, Ultrafast Intense Laser Science, spanning atomic and molecular physics, molecular science, and optical science. Its progress is being stimulated by the recent development of ultrafast laser technologies. Highlights of this second volume include Coulomb explosion and fragmentation of molecules, control of chemical dynamics, high-order harmonic generation, propagation and filamentation, and laser-plasma interaction. All chapters are authored by foremost experts in their fields and the texts are written at a level accessible to newcomers and graduate students, each chapter beginning with an introductory overview.

Farris-Tang retractor in optic nerve sheath decompression surgery.

Science.gov (United States)

Spiegel, Jennifer A; Sokol, Jason A; Whittaker, Thomas J; Bernard, Benjamin; Farris, Bradley K

2016-01-01

Our purpose is to introduce the use of the Farris-Tang retractor in optic nerve sheath decompression surgery. The procedure of optic nerve sheath fenestration was reviewed at our tertiary care teaching hospital, including the use of the Farris-Tang retractor. Pseudotumor cerebri is a syndrome of increased intracranial pressure without a clear cause. Surgical treatment can be effective in cases in which medical therapy has failed and disc swelling with visual field loss progresses. Optic nerve sheath decompression surgery (ONDS) involves cutting slits or windows in the optic nerve sheath to allow cerebrospinal fluid to escape, reducing the pressure around the optic nerve. We introduce the Farris-Tang retractor, a retractor that allows for excellent visualization of the optic nerve sheath during this surgery, facilitating the fenestration of the sheath and visualization of the subsequent cerebrospinal fluid egress. Utilizing a medial conjunctival approach, the Farris-Tang retractor allows for easy retraction of the medial orbital tissue and reduces the incidence of orbital fat protrusion through Tenon's capsule. The Farris-Tang retractor allows safe, easy, and effective access to the optic nerve with good visualization in optic nerve sheath decompression surgery. This, in turn, allows for greater surgical efficiency and positive patient outcomes.

Classifying murine glomerulonephritis using optical coherence tomography and optical coherence elastography.

Science.gov (United States)

Liu, Chih-Hao; Du, Yong; Singh, Manmohan; Wu, Chen; Han, Zhaolong; Li, Jiasong; Chang, Anthony; Mohan, Chandra; Larin, Kirill V

2016-08-01

Acute glomerulonephritis caused by antiglomerular basement membrane marked by high mortality. The primary reason for this is delayed diagnosis via blood examination, urine analysis, tissue biopsy, or ultrasound and X-ray computed tomography imaging. Blood, urine, and tissue-based diagnoses can be time consuming, while ultrasound and CT imaging have relatively low spatial resolution, with reduced sensitivity. Optical coherence tomography is a noninvasive and high-resolution imaging technique that provides superior spatial resolution (micrometer scale) as compared to ultrasound and CT. Changes in tissue properties can be detected based on the optical metrics analyzed from the OCT signals, such as optical attenuation and speckle variance. Furthermore, OCT does not rely on ionizing radiation as with CT imaging. In addition to structural changes, the elasticity of the kidney can significantly change due to nephritis. In this work, OCT has been utilized to quantify the difference in tissue properties between healthy and nephritic murine kidneys. Although OCT imaging could identify the diseased tissue, its classification accuracy is clinically inadequate. By combining optical metrics with elasticity, the classification accuracy improves from 76% to 95%. These results show that OCT combined with OCE can be a powerful tool for identifying and classifying nephritis. Therefore, the OCT/OCE method could potentially be used as a minimally invasive tool for longitudinal studies during the progression and therapy of glomerulonephritis as well as complement and, perhaps, substitute highly invasive tissue biopsies. Elastic-wave propagation in mouse healthy and nephritic kidneys. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

New treatments for Optic Neuritis

International Nuclear Information System (INIS)

Horton, J. C.

2005-01-01

Optic neuritis is used as a general term for any acute optic neuropathy caused by inflammation, and in a more specific sense, to refer to the optic neuropathy that occurs in patients with multiple sclerosis. The latter disease, often called demyelinating neuritis, occurs most often in women, is usually retrobulbar, is accompanied by pain with eye movements, and generally recovers spontaneously. For patients with no prior history of neurological disease, the 10-year risk of second demyelinating event after an initial attack of optic neuritis is 38%. This risk is greater in patients who have demyelinating plaques present on brain magnetic resonance imaging. The Optic Neuritis Treatment Trial showed no benefit of corticosteroid therapy on visual acuity, measured six months after an attack of neuritis. However, at one month there was more rapid improvement acuity in patients treated with intravenous steroids. Long-term treatment with interferon, an immunosuppressive agent, has been shown to reduce the rate of demyelinating events and plaque accumulation measured by magnetic resonance imaging. A new drug, natalizumab, has also been shown to reduce the formation of new demyelinating plaques in patients with multiple sclerosis. Unfortunately, treatment with interferon and natalizumab has resulted in progressive multifocal leukoencephalopathy, a rare and fatal opportunistic viral infection of the brain, in 3/5000 patients. Despite this tragic setback, the advent of new drug therapies has brightened the prognosis for patients with multiple sclerosis. (author)

Embodied memory: effective and stable perception by combining optic flow and image structure.

Science.gov (United States)

Pan, Jing Samantha; Bingham, Ned; Bingham, Geoffrey P

2013-12-01

Visual perception studies typically focus either on optic flow structure or image structure, but not on the combination and interaction of these two sources of information. Each offers unique strengths in contrast to the other's weaknesses. Optic flow yields intrinsically powerful information about 3D structure, but is ephemeral. It ceases when motion stops. Image structure is less powerful in specifying 3D structure, but is stable. It remains when motion stops. Optic flow and image structure are intrinsically related in vision because the optic flow carries one image to the next. This relation is especially important in the context of progressive occlusion, in which optic flow provides information about the location of targets hidden in subsequent image structure. In four experiments, we investigated the role of image structure in "embodied memory" in contrast to memory that is only in the head. We found that either optic flow (Experiment 1) or image structure (Experiment 2) alone were relatively ineffective, whereas the combination was effective and, in contrast to conditions requiring reliance on memory-in-the-head, much more stable over extended time (Experiments 2 through 4). Limits well documented for visual short memory (that is, memory-in-the-head) were strongly exceeded by embodied memory. The findings support J. J. Gibson's (1979/1986, The Ecological Approach to Visual Perception, Boston, MA, Houghton Mifflin) insights about progressive occlusion and the embodied nature of perception and memory.

Determination of uranium in urine by fluorometry

International Nuclear Information System (INIS)

Afsar, M.; Aziz, A.; Mubarak, M.A.

1978-01-01

The report describes fluorometric determination of traces of uranium in the urine of mine workers and persons handling uranium. After preliminary treatment uranium is extracted by solvent extraction with TBP:MIBK mixtures. An aliquot of the extracted solution is fused with high carbonate flux at 650 0 C in platinum dishes. The fluorescence of fused sample is measured using a fluorometer. Various fusion parameters are discussed. The procedure for the operation and calibration of fluorometer is also described

Integrated liquid-core optical fibers for ultra-efficient nonlinear liquid photonics.

Science.gov (United States)

Kieu, K; Schneebeli, L; Norwood, R A; Peyghambarian, N

2012-03-26

We have developed a novel integrated platform for liquid photonics based on liquid core optical fiber (LCOF). The platform is created by fusion splicing liquid core optical fiber to standard single-mode optical fiber making it fully integrated and practical - a major challenge that has greatly hindered progress in liquid-photonic applications. As an example, we report here the realization of ultralow threshold Raman generation using an integrated CS₂ filled LCOF pumped with sub-nanosecond pulses at 532 nm and 1064 nm. The measured energy threshold for the Stokes generation is 1nJ, about three orders of magnitude lower than previously reported values in the literature for hydrogen gas, a popular Raman medium. The integrated LCOF platform opens up new possibilities for ultralow power nonlinear optics such as efficient white light generation for displays, mid-IR generation, slow light generation, parametric amplification, all-optical switching and wavelength conversion using liquids that have orders of magnitude larger optical nonlinearities compared with silica glass.

Eye-orbit NMR imaging: works in progress

International Nuclear Information System (INIS)

Cabanis, E.A.; Iba-Zizen, M.T.; Tourbah, A.; Stievenart, J.L.; Nguyen, T.H.; Trocme, P.; Mottier, N.; Thibierge, M.; Haut, J.; Hamard, H.

1995-01-01

Progress in brain and eyes magnetic resonance imagery follows improvements in data processing. Most of the 45000 examinations performed since 1984 concerns the head (90%) and a third of them concerns the optic system (from the cornea to the calcarine fissure). The majority of the explorations has been done with a SIGNA GE device (1.5 T, 4 and 5x versions). Image treatment is performed on Advantage Windows stations. Proton spectroscopy is becoming a major tool in myelin evaluation. The spatial resolution of bi-dimensional descriptive anatomy has increased (see for instance the ciliary body and the axonal group of the optical nerve). Problem remains in the fusion of colour or grey scale X-ray scanning images with magnetic resonance images for surface or transparency tri-dimensional analysis of regional anatomy. Dynamic ( 4 D ) anatomy of cone muscles is favourable to the comprehension of theoretical data or precise clinical situations. (J.S.)

A review of fiber-optic corrosion sensor in civil engineering

Science.gov (United States)

Luo, Dong; Li, Junnan; Li, Yuanyuan

2018-05-01

Fiber-optical corrosion sensor (FOCS) is the research hotspot of corrosion monitoring sensor in recent years. It has the advantages of lightness, simplicity, anti-electromagnetic interference and distributed measurement, so it has an attractive application prospect. In this paper, the mechanism of metal corrosion is introduced. Several common methods for detecting optical fiber corrosion sensors are presented, and the latest progress of optical fiber corrosion sensors in recent years is described. We need to design a set of sensor devices that can directly monitor the corrosion of reinforcing steel bars directly, and propose a method of time dependent reliability assessment based on monitoring data, so as to form a complete research path.

Metrology of reflection optics for synchrotron radiation

International Nuclear Information System (INIS)

Takacs, P.Z.

1985-09-01

Recent years have seen an almost explosive growth in the number of beam lines on new and existing synchrotron radiation facilities throughout the world. The need for optical components to utilize the unique characteristics of synchrotron radiation has increased accordingly. Unfortunately, the technology to manufacture and measure the large, smooth, exotic optical surfaces required to focus and steer the synchrotron radiation beam has not progressed as rapidly as the operational demands on these components. Most companies do not wish to become involved with a project that requires producing a single, very expensive, aspheric optic with surface roughness and figure tolerances that are beyond their capabilities to measure. This paper will review some of the experiences of the National Synchrotron Light Source in procuring grazing incidence optical components over the past several years. We will review the specification process - how it is related to the function of the optic, and how it relates to the metrology available during the manufacturing process and after delivery to the user's laboratory. We will also discuss practical aspects of our experience with new technologies, such as single point diamond turning of metal mirrors and the use of SiC as a mirror material. Recent advances in metrology instrumentation have the potential to move the measurement of surface figure and finish from the research laboratory into the optical shop, which should stimulate growth and interest in the manufacturing of optics to meet the needs of the synchrotron radiation user community

Progress in nanophotonics 3

CERN Document Server

Yatsui, Takashi

2015-01-01

This book focuses on the recent progress in nanophotonics technology to be used to develop novel nano-optical devices, fabrication technology and advanced systems. It reviews light-emitting diodes and lasers made of silicon bulk crystals in which the light emission principle is based on dressed-photon-phonons. Further topics include: theoretical studies of optoelectronic properties of molecular condensates for organic solar cells and light-emitting devices, the basics of topological light beams together with their important properties for laser spectroscopy, spatially localized modes emerging in nonlinear discrete dynamic systems and theoretical methods to explore the dynamics of nanoparticles by the light-induced force of tailored light fields under thermal fluctuations. These topics are reviewed by leading scientists. This overview is a variable resource for engineers and scientists working in the field of nanophotonics.

A topological quantum optics interface.

Science.gov (United States)

Barik, Sabyasachi; Karasahin, Aziz; Flower, Christopher; Cai, Tao; Miyake, Hirokazu; DeGottardi, Wade; Hafezi, Mohammad; Waks, Edo

2018-02-09

The application of topology in optics has led to a new paradigm in developing photonic devices with robust properties against disorder. Although considerable progress on topological phenomena has been achieved in the classical domain, the realization of strong light-matter coupling in the quantum domain remains unexplored. We demonstrate a strong interface between single quantum emitters and topological photonic states. Our approach creates robust counterpropagating edge states at the boundary of two distinct topological photonic crystals. We demonstrate the chiral emission of a quantum emitter into these modes and establish their robustness against sharp bends. This approach may enable the development of quantum optics devices with built-in protection, with potential applications in quantum simulation and sensing. Copyright © 2018 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.

Optics/Optical Diagnostics Laboratory

Data.gov (United States)

Federal Laboratory Consortium — The Optics/Optical Diagnostics Laboratory supports graduate instruction in optics, optical and laser diagnostics and electro-optics. The optics laboratory provides...

Recent Progress on Plasmon-Enhanced Fluorescence

Directory of Open Access Journals (Sweden)

Dong Jun

2015-12-01

Full Text Available The optically generated collective electron density waves on metal–dielectric boundaries known as surface plasmons have been of great scientific interest since their discovery. Being electromagnetic waves on gold or silver nanoparticle’s surface, localised surface plasmons (LSP can strongly enhance the electromagnetic field. These strong electromagnetic fields near the metal surfaces have been used in various applications like surface enhanced spectroscopy (SES, plasmonic lithography, plasmonic trapping of particles, and plasmonic catalysis. Resonant coupling of LSPs to fluorophore can strongly enhance the emission intensity, the angular distribution, and the polarisation of the emitted radiation and even the speed of radiative decay, which is so-called plasmon enhanced fluorescence (PEF. As a result, more and more reports on surface-enhanced fluorescence have appeared, such as SPASER-s, plasmon assisted lasing, single molecule fluorescence measurements, surface plasmoncoupled emission (SPCE in biological sensing, optical orbit designs etc. In this review, we focus on recent advanced reports on plasmon-enhanced fluorescence (PEF. First, the mechanism of PEF and early results of enhanced fluorescence observed by metal nanostructure will be introduced. Then, the enhanced substrates, including periodical and nonperiodical nanostructure, will be discussed and the most important factor of the spacer between molecule and surface and wavelength dependence on PEF is demonstrated. Finally, the recent progress of tipenhanced fluorescence and PEF from the rare-earth doped up-conversion (UC and down-conversion (DC nanoparticles (NPs are also commented upon. This review provides an introduction to fundamentals of PEF, illustrates the current progress in the design of metallic nanostructures for efficient fluorescence signal amplification that utilises propagating and localised surface plasmons.

Nonlinear optics with broad-band lasers: Progress report, July 15, 1987-April 14, 1988

International Nuclear Information System (INIS)

Raymer, M.G.

1988-01-01

During this reporting period several important results were obtained on the fluctuation dynamics of both continuous-wave (cw) and pulsed dye lasers, as well as their effects in certain nonlinear optical processes: (1) A new method discovered for producing optical pulses with broad bandwidths (5 GHz) and smooth, slowly varying amplitude. The bandwidth is determined purely by phase fluctuations. (2) A theoretical treatment of pulsed dye lasers was developed to explain intensity autocorrelation measurements. (3) The effects of laser bandwidth on the resonance fluorescence spectrum of a two-level atom were calculated. (4) The source of mode intensity fluctuations in a multimode, cw dye laser were shown, both experimentally and theoretically, to be caused by deterministic chaos, rather than quantum noise as had been previously assumed in the literature

High-Q photonic resonators and electro-optic coupling using silicon-on-lithium-niobate

Science.gov (United States)

Witmer, Jeremy D.; Valery, Joseph A.; Arrangoiz-Arriola, Patricio; Sarabalis, Christopher J.; Hill, Jeff T.; Safavi-Naeini, Amir H.

2017-04-01

Future quantum networks, in which superconducting quantum processors are connected via optical links, will require microwave-to-optical photon converters that preserve entanglement. A doubly-resonant electro-optic modulator (EOM) is a promising platform to realize this conversion. Here, we present our progress towards building such a modulator by demonstrating the optically-resonant half of the device. We demonstrate high quality (Q) factor ring, disk and photonic crystal resonators using a hybrid silicon-on-lithium-niobate material system. Optical Q factors up to 730,000 are achieved, corresponding to propagation loss of 0.8 dB/cm. We also use the electro-optic effect to modulate the resonance frequency of a photonic crystal cavity, achieving a electro-optic modulation coefficient between 1 and 2 pm/V. In addition to quantum technology, we expect that our results will be useful both in traditional silicon photonics applications and in high-sensitivity acousto-optic devices.

Optical Access Networks

Science.gov (United States)

Zheng, Jun; Ansari, Nirwan

2005-01-01

have been receiving tremendous attention from both academia and industry. A large number of research activities have been carried out or are now underway this hot area. The purpose of this feature issue is to expose the networking community to the latest research breakthroughs and progresses in the area of optical access networks. Scope of Contributions This feature issue aims to present a collection of papers that focus on the state-of-the-art research in various networking aspects of optical access networks. Original papers are solicited from all researchers involved in area of optical access networks. Topics of interest include but not limited to: Optical access network architectures and protocols Passive optical networks (BPON, EPON, GPON, etc.) Active optical networks Multiple access control Multiservices and QoS provisioning Network survivability Field trials and standards Performance modeling and analysis Manuscript Submission To submit to this special issue, follow the normal procedure for submission to JON, indicating ``Optical Access Networks feature' in the ``Comments' field of the online submission form. For all other questions relating to this feature issue, please send an e-mail to jon@osa.org, subject line ``Optical Access Networks' Additional information can be found on the JON website: http://www.osa-jon.org/submission/. Submission Deadline: 1 June 2005

Nanoscale on-chip all-optical logic parity checker in integrated plasmonic circuits in optical communication range

Science.gov (United States)

Wang, Feifan; Gong, Zibo; Hu, Xiaoyong; Yang, Xiaoyu; Yang, Hong; Gong, Qihuang

2016-01-01

The nanoscale chip-integrated all-optical logic parity checker is an essential core component for optical computing systems and ultrahigh-speed ultrawide-band information processing chips. Unfortunately, little experimental progress has been made in development of these devices to date because of material bottleneck limitations and a lack of effective realization mechanisms. Here, we report a simple and efficient strategy for direct realization of nanoscale chip-integrated all-optical logic parity checkers in integrated plasmonic circuits in the optical communication range. The proposed parity checker consists of two-level cascaded exclusive-OR (XOR) logic gates that are realized based on the linear interference of surface plasmon polaritons propagating in the plasmonic waveguides. The parity of the number of logic 1s in the incident four-bit logic signals is determined, and the output signal is given the logic state 0 for even parity (and 1 for odd parity). Compared with previous reports, the overall device feature size is reduced by more than two orders of magnitude, while ultralow energy consumption is maintained. This work raises the possibility of realization of large-scale integrated information processing chips based on integrated plasmonic circuits, and also provides a way to overcome the intrinsic limitations of serious surface plasmon polariton losses for on-chip integration applications. PMID:27073154

Nanoscale on-chip all-optical logic parity checker in integrated plasmonic circuits in optical communication range.

Science.gov (United States)

Wang, Feifan; Gong, Zibo; Hu, Xiaoyong; Yang, Xiaoyu; Yang, Hong; Gong, Qihuang

2016-04-13

The nanoscale chip-integrated all-optical logic parity checker is an essential core component for optical computing systems and ultrahigh-speed ultrawide-band information processing chips. Unfortunately, little experimental progress has been made in development of these devices to date because of material bottleneck limitations and a lack of effective realization mechanisms. Here, we report a simple and efficient strategy for direct realization of nanoscale chip-integrated all-optical logic parity checkers in integrated plasmonic circuits in the optical communication range. The proposed parity checker consists of two-level cascaded exclusive-OR (XOR) logic gates that are realized based on the linear interference of surface plasmon polaritons propagating in the plasmonic waveguides. The parity of the number of logic 1s in the incident four-bit logic signals is determined, and the output signal is given the logic state 0 for even parity (and 1 for odd parity). Compared with previous reports, the overall device feature size is reduced by more than two orders of magnitude, while ultralow energy consumption is maintained. This work raises the possibility of realization of large-scale integrated information processing chips based on integrated plasmonic circuits, and also provides a way to overcome the intrinsic limitations of serious surface plasmon polariton losses for on-chip integration applications.

Optical Coherence Tomography Predictors of Risk for Progression to Non-Neovascular Atrophic Age-Related Macular Degeneration.

Science.gov (United States)

Sleiman, Karim; Veerappan, Malini; Winter, Katrina P; McCall, Michelle N; Yiu, Glenn; Farsiu, Sina; Chew, Emily Y; Clemons, Traci; Toth, Cynthia A

2017-12-01

Appearance of geographic atrophy (GA) on color photography (CP) is preceded by specific features on spectral-domain optical coherence tomography (SD OCT). We aimed to build SD OCT-based risk assessment models for 5-year new onset of GA and central GA on CP. Prospective, longitudinal study. Age-Related Eye Disease Study 2 Ancillary SD OCT study participants with age-related macular degeneration (AMD) with bilateral large drusen or noncentral GA and at least 1 eye without advanced disease (n = 317). For 1 eye per participant, qualitative and quantitative SD OCT variables were derived from standardized grading and semiautomated segmentation, respectively, at baseline. Up to 7 years later, annual outcomes were extracted and analyzed to fit multivariate logistic regression models and build a risk calculator. New onset of CP-visible GA and central GA. Over a follow-up median of 4.0 years and among 292 AMD eyes (without advanced disease at baseline) with complete outcome data, 46 (15.8%) developed central GA. Among 265 eyes without any GA on baseline CP, 70 (26.4%) developed CP-visible GA. Final multivariate models were adjusted for age. In the model for GA, the independent predicting SD OCT factors (P segment loss, RPE drusen complex volume, and RPE drusen complex abnormal thinning volume. For central GA, the factors (P segmentation, drusen characteristics, and retinal pathology-for progression to CP-visible GA over up to 5 years. This calculator may simplify SD OCT grading and with future validation has a promising role as a clinical prognostic tool. Copyright © 2017 American Academy of Ophthalmology. All rights reserved.

Cone structure imaged with adaptive optics scanning laser ophthalmoscopy in eyes with nonneovascular age-related macular degeneration.

Science.gov (United States)

Zayit-Soudry, Shiri; Duncan, Jacque L; Syed, Reema; Menghini, Moreno; Roorda, Austin J

2013-11-15

To evaluate cone spacing using adaptive optics scanning laser ophthalmoscopy (AOSLO) in eyes with nonneovascular AMD, and to correlate progression of AOSLO-derived cone measures with standard measures of macular structure. Adaptive optics scanning laser ophthalmoscopy images were obtained over 12 to 21 months from seven patients with AMD including four eyes with geographic atrophy (GA) and four eyes with drusen. Adaptive optics scanning laser ophthalmoscopy images were overlaid with color, infrared, and autofluorescence fundus photographs and spectral domain optical coherence tomography (SD-OCT) images to allow direct correlation of cone parameters with macular structure. Cone spacing was measured for each visit in selected regions including areas over drusen (n = 29), at GA margins (n = 14), and regions without drusen or GA (n = 13) and compared with normal, age-similar values. Adaptive optics scanning laser ophthalmoscopy imaging revealed continuous cone mosaics up to the GA edge and overlying drusen, although reduced cone reflectivity often resulted in hyporeflective AOSLO signals at these locations. Baseline cone spacing measures were normal in 13/13 unaffected regions, 26/28 drusen regions, and 12/14 GA margin regions. Although standard clinical measures showed progression of GA in all study eyes, cone spacing remained within normal ranges in most drusen regions and all GA margin regions. Adaptive optics scanning laser ophthalmoscopy provides adequate resolution for quantitative measurement of cone spacing at the margin of GA and over drusen in eyes with AMD. Although cone spacing was often normal at baseline and remained normal over time, these regions showed focal areas of decreased cone reflectivity. These findings may provide insight into the pathophysiology of AMD progression. (ClinicalTrials.gov number, NCT00254605).

Optic nerve sheath meningioma treated with radiation conformal therapy. Clinical case report with long follow up

International Nuclear Information System (INIS)

Zomosa R, Gustavo; Cruz T, Sebastian; Miranda G, Gonzalo; Harbst S, Hans

2016-01-01

Optic nerve sheath meningiomas (ONSM) are rare tumors of the anterior visual pathway. Without treatment, tumor growth leads to progressive loss of visual acuity and blindness due to optic nerve compression. Case report: Patient, female, 42 years without other morbility , begins in 1992 with decreased visual acuity of the left eye, magnetic resonance imaging (MRI) showed enlargement of the left optic nerve sheath, suggestive of ONSM. On that occasion, orbit exploration failed, so it was decided to follow up with annual clinical and imaging controls. About ten years later, begins with progressive deterioration of visual acuity and visual field , with ptosis and ocular motor palsy of the left eye, confirmed with neuro-ophthalmological examinations. MRI shows tumor progression. A new surgical approach was discarded by the risk of visual worsening. A conformal radiotherapy was performed with a fractionated 54 Gy dose. Today, at age 65, after 24 years of follow up,13 post radiation therapy. clinical and radiological stability of ONSM is confirmed. Discussion: Conformal radiotherapy has been shown as an effective therapy, with fewer complications and better outcomes in the preservation of visual function in the long term follow up Radio-fluoro guided surgery in high grade gliomas

Assessment of nerve ultrastructure by fibre-optic confocal microscopy.

Science.gov (United States)

Cushway, T R; Lanzetta, M; Cox, G; Trickett, R; Owen, E R

1996-01-01

Fibre-optic technology combined with confocality produces a microscope capable of optical thin sectioning. In this original study, tibial nerves have been stained in a rat model with a vital dye, 4-(4-diethylaminostyryl)-N-methylpyridinium iodide, and analysed by fibre-optic confocal microscopy to produce detailed images of nerve ultrastructure. Schwann cells, nodes of Ranvier and longitudinal myelinated sheaths enclosing axons were clearly visible. Single axons appeared as brightly staining longitudinal structures. This allowed easy tracing of multiple signal axons within the nerve tissue. An accurate measurement of internodal lengths was easily accomplished. This technique is comparable to current histological techniques, but does not require biopsy, thin sectioning or tissue fixing. This study offers a standard for further in vivo microscopy, including the possibility of monitoring the progression of nerve regeneration following microsurgical neurorraphy.

Continuous all-optical deceleration of molecular beams

Science.gov (United States)

Jayich, Andrew; Chen, Gary; Long, Xueping; Wang, Anna; Campbell, Wesley

2014-05-01

A significant impediment to generating ultracold molecules is slowing a molecular beam to velocities where the molecules can be cooled and trapped. We report on progress toward addressing this issue with a general optical deceleration technique for molecular and atomic beams. We propose addressing the molecular beam with a pump and dump pulse sequence from a mode-locked laser. The pump pulse counter-propagates with respect to the beam and drives the molecules to the excited state. The dump pulse co-propagates and stimulates emission, driving the molecules back to the ground state. This cycle transfers 2 ℏk of momentum and can generate very large optical forces, not limited by the spontaneous emission lifetime of the molecule or atom. Importantly, avoiding spontaneous emission limits the branching to dark states. This technique can later be augmented with cooling and trapping. We are working towards demonstrating this optical force by accelerating a cold atomic sample.

Actively stabilized optical fiber interferometry technique for online/in-process surface measurement

International Nuclear Information System (INIS)

Wang Kaiwei; Martin, Haydn; Jiang Xiangqian

2008-01-01

In this paper, we report the recent progress in optical-beam scanning fiber interferometry for potential online nanoscale surface measurement based on the previous research. It attempts to generate a robust and miniature measurement device for future development into a multiprobe array measurement system. In this research, both fiber-optic-interferometry and the wavelength-division-multiplexing techniques have been used, so that the optical probe and the optical interferometer are well spaced and fast surface scanning can be carried out, allowing flexibility for online measurement. In addition, this system provides a self-reference signal to stabilize the optical detection with high common-mode noise suppression by adopting an active phase tracking and stabilization technique. Low-frequency noise was significantly reduced compared with unstabilized result. The measurement of a sample surface shows an attained repeatability of 3.3 nm

On the optical stability of high-resolution transmission electron microscopes

International Nuclear Information System (INIS)

Barthel, J.; Thust, A.

2013-01-01

In the recent two decades the technique of high-resolution transmission electron microscopy experienced an unprecedented progress through the introduction of hardware aberration correctors and by the improvement of the achievable resolution to the sub-Ångström level. The important aspect that aberration correction at a given resolution requires also a well defined amount of optical stability has received little attention so far. Therefore we investigate the qualification of a variety of high-resolution electron microscopes to maintain an aberration corrected optical state in terms of an optical lifetime. We develop a comprehensive statistical framework for the estimation of the optical lifetime and find remarkably low values between tens of seconds and a couple of minutes. Probability curves are introduced, which inform the operator about the chance to work still in the fully aberration corrected state. - Highlights: • We investigate the temporal stability of optical aberrations in HRTEM. • We develop a statistical framework for the estimation of optical lifetimes. • We introduce plots showing the success probability for aberration-free work. • Optical lifetimes in sub-Ångström electron microscopy are surprisingly low. • The success of aberration correction depends strongly on the optical stability

Design progress of the solar UV-Vis-IR telescope (SUVIT) aboard SOLAR-C

Science.gov (United States)

Katsukawa, Y.; Ichimoto, K.; Suematsu, Y.; Hara, H.; Kano, R.; Shimizu, T.; Matsuzaki, K.

2013-09-01

We present a design progress of the Solar UV-Vis-IR Telescope (SUVIT) aboard the next Japanese solar mission SOLAR-C. SUVIT has an aperture diameter of ~1.4 m for achieving spectro-polarimetric observations with spatial and temporal resolution exceeding the Hinode Solar Optical Telescope (SOT). We have studied structural and thermal designs of the optical telescope as well as the optical interface between the telescope and the focal plane instruments. The focal plane instruments are installed into two packages, filtergraph and spectrograph packages. The spectropolarimeter is the instrument dedicated to accurate polarimetry in the three spectrum windows at 525 nm, 854 nm, and 1083 nm for observing magnetic fields at both the photospheric and chromospheric layers. We made optical design of the spectrograph accommodating the conventional slit spectrograph and the integral field unit (IFU) for two-dimensional coverage. We are running feasibility study of the IFU using fiber arrays consisting of rectangular cores.

Incipient nonarteritic anterior ischemic optic neuropathy.

Science.gov (United States)

Hayreh, Sohan Singh; Zimmerman, M Bridget

2007-09-01

To describe the clinical entity of incipient nonarteritic anterior ischemic optic neuropathy (NAION). Cohort study. Fifty-four patients (60 eyes) seen in our clinic from 1973 through 2000. At their first visit to our clinic, all patients gave a detailed ophthalmic and medical history and underwent a comprehensive ophthalmic evaluation, color fundus photography, and fluorescein fundus angiography. At each follow-up visit (of 49 patients [55 eyes]), the same ophthalmic evaluation was performed, except for fluorescein fundus angiography. Clinical features of incipient NAION. Mean age (+/- standard deviation) of the patients was 58.7+/-15.9 years. Median follow-up time was 6.3 years (interquartile range [IQR], 2.1-8.5). At initial visit, all had optic disc edema (ODE) without any visual loss attributable to NAION. In 55%, the fellow eye had classic NAION; in 25%, incipient progressed to classic NAION (after a median time of 5.8 weeks [IQR, 3.2-10.1]); and in 20%, classic NAION developed after resolution of the first episode of incipient NAION. Patients with incipient, compared with classic, NAION had a greater prevalence of diabetes mellitus (Pheart disease (P = 0.046). Patients who progressed to classic NAION versus those who did not were significantly younger (P = 0.025), and their visual acuity worsened in 31% and 0%, respectively, and remained stable in 62% and 98%, respectively; in the eyes with progression, central (in 31%) and peripheral (in 77%) visual fields worsened compared with only 1 eye and 2 eyes, respectively, that did not (P = 0.01 and Pversus 9.6 weeks (IQR, 6.0-17.7) in those who did not progress. The results show that incipient NAION is a distinct clinical entity, with asymptomatic ODE and no visual loss attributable to NAION. When a patient seeks treatment with asymptomatic ODE, incipient NAION must be borne in mind as a strong possibility in those who have had classic NAION in the fellow eye, in diabetics of all ages, and in those with high risk

Loss of Ikbkap Causes Slow, Progressive Retinal Degeneration in a Mouse Model of Familial Dysautonomia.

Science.gov (United States)

Ueki, Yumi; Ramirez, Grisela; Salcedo, Ernesto; Stabio, Maureen E; Lefcort, Frances

2016-01-01

Familial dysautonomia (FD) is an autosomal recessive congenital neuropathy that is caused by a mutation in the gene for inhibitor of kappa B kinase complex-associated protein ( IKBKAP ). Although FD patients suffer from multiple neuropathies, a major debilitation that affects their quality of life is progressive blindness. To determine the requirement for Ikbkap in the developing and adult retina, we generated Ikbkap conditional knockout (CKO) mice using a TUBA1a promoter-Cre ( Tα1-Cre ). In the retina, Tα1-Cre expression is detected predominantly in retinal ganglion cells (RGCs). At 6 months, significant loss of RGCs had occurred in the CKO retinas, with the greatest loss in the temporal retina, which is the same spatial phenotype observed in FD, Leber hereditary optic neuropathy, and dominant optic atrophy. Interestingly, the melanopsin-positive RGCs were resistant to degeneration. By 9 months, signs of photoreceptor degeneration were observed, which later progressed to panretinal degeneration, including RGC and photoreceptor loss, optic nerve thinning, Müller glial activation, and disruption of layers. Taking these results together, we conclude that although Ikbkap is not required for normal development of RGCs, its loss causes a slow, progressive RGC degeneration most severely in the temporal retina, which is later followed by indirect photoreceptor loss and complete retinal disorganization. This mouse model of FD is not only useful for identifying the mechanisms mediating retinal degeneration, but also provides a model system in which to attempt to test therapeutics that may mitigate the loss of vision in FD patients.

Environmental studies

International Nuclear Information System (INIS)

Anon.

1976-01-01

The utility of high-resolution liquid chromatography for separating organophosphorus compounds from natural waters and effluents from coal processing plants was investigated. The procedures were optimized for the separation of phenol-type compounds from aqueous effluents from coal liquefaction processes. Preliminary results are reported from applications for the analysis of marine waters from estuaries and municipal drinking water. An automated analytical system, using a bifurcated, fiber-optic fluorometer, was developed for the isolation and identification of trace polynuclear aromatic hydrocarbons for the continuous monitoring of coal liquefaction and coal gasification liquid effluents. The practice of chlorinating cooling waters was evaluated with respect to the formation of toxic chlorinated organic compounds of environmental importance

Optical properties of high-Tc superconductors

International Nuclear Information System (INIS)

Aspnes, D.E.; Kelly, M.K.

1989-01-01

The authors summarize the present status of optical spectroscopy of high-T c superconductors. The optical properties of these materials resemble those of the more common transition metal oxides except for being highly anisotropic in the infrared (IR). This large IR anisotrophy and a need to rely solely on reflectance techniques has hindered progress in obtaining accurate IR data and interpreting these data in terms of microscopic mechanisms. However, experimental consistency is now being approached with single-crystal samples, although interpretations of these data remain controversial and an unequivocal demonstration of a superconducting gap structure has not yet been achieved. The mid IR exhibits an absorption band whose systematics are neither well established nor understood. The situation in the visible-near-ultraviolet (V-NUV) is better, partly because of greatly reduced optical anisotropy and the availability of alternative measurement techniques that are not strongly affected by the lower optical quality of sintered material. As polycrystalline, sintered samples can be prepared relatively easily over wide ranges of composition, doping, and chemical substitution, most work on studying the chemical systematics of these materials has been done in this spectral range and some of the structure that appears here has been positively identified

Integrated-optics heralded controlled-NOT gate for polarization-encoded qubits

Science.gov (United States)

Zeuner, Jonas; Sharma, Aditya N.; Tillmann, Max; Heilmann, René; Gräfe, Markus; Moqanaki, Amir; Szameit, Alexander; Walther, Philip

2018-03-01

Recent progress in integrated-optics technology has made photonics a promising platform for quantum networks and quantum computation protocols. Integrated optical circuits are characterized by small device footprints and unrivalled intrinsic interferometric stability. Here, we take advantage of femtosecond-laser-written waveguides' ability to process polarization-encoded qubits and present an implementation of a heralded controlled-NOT gate on chip. We evaluate the gate performance in the computational basis and a superposition basis, showing that the gate can create polarization entanglement between two photons. Transmission through the integrated device is optimized using thermally expanded core fibers and adiabatically reduced mode-field diameters at the waveguide facets. This demonstration underlines the feasibility of integrated quantum gates for all-optical quantum networks and quantum repeaters.

Transsynaptic neuronal degeneration of optic nerves associated with bilateral occipital lesions

Directory of Open Access Journals (Sweden)

Sachdev Mahipal

1990-01-01

Full Text Available A case is reported of a 9-year old male who presented with abnormal behaviour and progressive diminution of vision. Pupils were middilated in both eyes but the pupillary reflexes were preserved. Fundus examination revealed a bilateral optic atrophy and radiological investigations showed a bilateral occipital calcification. We hereby document a case of retrograde transsynaptic neuronal degeneration of the visual system secondary to bilateral occipital lesions. Transsynapptic neuronal degeneration of optic nerves consequent to occipital lobe lesions is a rare phenomenon. Experimentally occipital lobe ablation in non-human primates has been shown to result in optic atrophy. Herein, we document a case of retrograde transsynaptic neuronal degeneration of the visual system secondary to bilateral occipital lesions.

Information Loss from Technological Progress

International Nuclear Information System (INIS)

Townsend, P D

2014-01-01

Progress in electronics and optics offers faster computers, and rapid communication via the internet that is matched by ever larger and evolving storage systems. Instinctively one assumes that this must be totally beneficial. However advances in software and storage media are progressing in ways which are frequently incompatible with earlier systems and the economics and commercial pressures rarely guarantee total compatibility with earlier systems. Instead, the industries actively choose to force the users to purchase new systems and software. Thus we are moving forward with new technological variants that may have access to only the most recent systems and we will have lost earlier alternatives. The reality is that increased processing speed and storage capacity are matched by an equally rapid decline in the access and survival lifetime of older information. This pattern is not limited to modern electronic systems but is evident throughout history from writing on stone and clay tablets to papyrus and paper. It is equally evident in image systems from painting, through film, to magnetic tapes and digital cameras. In sound recording we have variously progressed from wax discs to vinyl, magnetic tape and CD formats. In each case the need for better definition and greater capacity has forced the earlier systems into oblivion. Indeed proposed interactive music systems could similarly relegate music CDs to specialist collections. The article will track some of the examples and discuss the consequences as well as noting that this information loss is further compounded by developments in language and changes in cultural views of different societies

Information Loss from Technological Progress

Science.gov (United States)

Townsend, P. D.

2014-12-01

Progress in electronics and optics offers faster computers, and rapid communication via the internet that is matched by ever larger and evolving storage systems. Instinctively one assumes that this must be totally beneficial. However advances in software and storage media are progressing in ways which are frequently incompatible with earlier systems and the economics and commercial pressures rarely guarantee total compatibility with earlier systems. Instead, the industries actively choose to force the users to purchase new systems and software. Thus we are moving forward with new technological variants that may have access to only the most recent systems and we will have lost earlier alternatives. The reality is that increased processing speed and storage capacity are matched by an equally rapid decline in the access and survival lifetime of older information. This pattern is not limited to modern electronic systems but is evident throughout history from writing on stone and clay tablets to papyrus and paper. It is equally evident in image systems from painting, through film, to magnetic tapes and digital cameras. In sound recording we have variously progressed from wax discs to vinyl, magnetic tape and CD formats. In each case the need for better definition and greater capacity has forced the earlier systems into oblivion. Indeed proposed interactive music systems could similarly relegate music CDs to specialist collections. The article will track some of the examples and discuss the consequences as well as noting that this information loss is further compounded by developments in language and changes in cultural views of different societies.

Change of Retinal Nerve Layer Thickness in Non-Arteritic Anterior Ischemic Optic Neuropathy Revealed by Fourier Domain Optical Coherence Tomography.

Science.gov (United States)

Han, Mei; Zhao, Chen; Han, Quan-Hong; Xie, Shiyong; Li, Yan

2016-08-01

To examine the changes of non-arteritic anterior ischemic optic neuropathy (NAION) by serial morphometry using Fourier domain optical coherence tomography (FD-OCT). Retrospective study in patients with newly diagnosed NAION (n=33, all unilateral) and controls (n=75 unilateral NAION patients with full contralateral eye vision) who underwent FD-OCT of the optic disk, optic nerve head (ONH), and macula within 1 week of onset and again 1, 3, 6, and 12 months later. The patients showed no improvement in vision during follow-up. Within 1 week of onset, all NAION eyes exhibited severe ONH fiber crowding and peripapillary retinal nerve fiber layer (RNFL) edema. Four had subretinal fluid accumulation and 12 had posterior vitreous detachment (PVD) at the optic disc surface. Ganglion cell complex (GCC) and RNFL thicknesses were reduced at 1 and 3 months (p < 0.05), with no deterioration thereafter. Initial RNFL/GCC contraction magnitude in the superior hemisphere correlated with the severity of inferior visual field deficits. NAION progression is characterized by an initial phase of accelerated RNFL and GCC deterioration. These results reveal that the kinetic change of neural retina in NAION and may have implication on the time window for treatment of NAION. FD-OCT is useful in the evaluation of NAION.

Photomultiplier protector for a fluorometer

International Nuclear Information System (INIS)

Priarone, P.; St John, P.A.

1982-01-01

The photometer is adapted for sensing radiation emitted by a chemical sample held in a cuvette received in a first compartment and includes a highly sensitive photomultiplier in a second compartment adjacent the first compartment for detecting fluorescent radiation emitted by the chemical sample and passing through an opening between the compartments. A mechanical protector assembly is provided for protecting the photomultiplier from ambient light and includes a movable light shield movable between a first position blocking the opening and a second position not blocking the opening. A knob is provided for moving the light shield to the first position to protect the photomultiplier from light entering from the first compartment when the first compartment is opened for insertion or removal of a cuvette, and for moving the light shield to the second position not blocking the opening to permit radiation emitted by the chemical sample to impinge upon the photomultiplier in the second compartment. The photometer also includes a mechanical interlocking assembly for ensuring that the first compartment cannot be opened unless the light shield is in the first position to prevent ambient light from entering the second compartment from the first compartment and reaching the photomultiplier

Atypical clinical presentation and long-term survival in a patient with optic nerve medulloepithelioma: a case report

Directory of Open Access Journals (Sweden)

Pastora-Salvador Natalia

2012-05-01

Full Text Available Abstract Introduction Medulloepithelioma is a rare congenital tumor of the primitive medullary neuroepithelium. A significant proportion of patients with medulloepithelioma arising from the optic nerve die from intracranial spread or cerebral metastasis. Because it has no known distinct clinical features and because of its low frequency, this tumor presents within the first two to six years of life and is usually misdiagnosed clinically as a different type of optic nerve tumor. Here, we describe a new and atypical case of medulloepithelioma of the optic nerve in a 12-year-old boy. To the best of our knowledge, he is the oldest reported patient to present with this disease and, now as an adult, has the longest documented period of disease-free survival. Case presentation A 12-year-old Caucasian boy with headache and unilateral amaurosis was referred for a presumed optic nerve glioma to our hospital. A computed tomography scan showed optic nerve enlargement, and fundoscopy showed a whitish mass at the optic disc. Our patient had been followed at his local hospital for four years for an 'optic disc cyst' with no change or progression. He experienced mild progressive visual impairment during that period. He was admitted for resection, and a histopathological analysis revealed a medulloepithelioma of the optic nerve. Supplemental orbital radiotherapy was performed. He remained disease-free for 25 years. Conclusions Medulloepithelioma of the optic nerve can clinically mimic more common pediatric tumors, such as optic glioma, meningioma, or retinoblastoma. Thus, medulloepithelioma should be included in the differential diagnoses of pediatric optic nerve lesions. Fundoscopy in these patients may provide relevant information for diagnosis. Anterior optic nerve medulloepitheliomas may behave differently from and have a better prognosis than medulloepitheliomas that have a more posterior location. Our case report illustrates that long-term survival can be

PREFACE: 23rd Congress of the International Commission for Optics (ICO 23)

Science.gov (United States)

Salgueiro, J. R.; Flores-Arias, M. T.; Vázquez-Dorrío, J. B.; Guzmán, Á.; Arakawa, Y.

2015-04-01

The 23rd Congress of the International Commission for Optics (ICO) was held in Santiago de Compostela (Spain) 26-29 August 2014, organized by the Universities of Vigo and Santiago de Compostela. Approximately 450 people attended the conference, sharing their knowledge in the cheerful, warm atmosphere of this lovely city. The conference was extremely successful in contributing to the mission of the ICO: to contribute worldwide, on an international basis, to the progress and diffusion of scientific and technological knowledge on optics and photonics. Optics and photonics have reached a critical level of importance for the development of our societies and are present in a great many aspects of our technological progress, from communication systems supporting the Internet to the most modern techniques in medicine. Consistent with the conference slogan Enlightening the Future, the meeting stressed the importance of optical science as a key to technological progress in the coming years. UNESCO's designation of 2015 as the International Year of Light and Light-Based Technologies (www.light2015.org) acknowledges the importance of raising global awareness of how light and light-based technologies are present in a large fraction of today's advances and how they can address challenges in important areas such as energy, education, agriculture, and health. The four-day conference highlighted eleven plenary talks by outstanding scientists working in important areas of optics and photonics. A. Aspect, T. Kippenberg (2013 ICO Prize awardee) and K. Razewski (2013 ICO Galileo Galilei Award) spoke on quantum optics; P. Russell and Yu. Kivshar lectured on topics related to optical processing devices as optical fibers and metamaterials for light shaping; N. X. Fang (2011 ICO Prize), U. Woggon, and A. Alú (2013 IUPAP Young Scientists Prize) discussed applications of optics to nanoscience; and K. Dholakia and J. Widjaja (2008 Galileo Galilei Award) presented in their plenaries

Optic neuropathies: the tip of the neurodegeneration iceberg

Science.gov (United States)

Carelli, Valerio; La Morgia, Chiara; Ross-Cisneros, Fred N.; Sadun, Alfredo A.

2017-01-01

Abstract The optic nerve and the cells that give origin to its 1.2 million axons, the retinal ganglion cells (RGCs), are particularly vulnerable to neurodegeneration related to mitochondrial dysfunction. Optic neuropathies may range from non-syndromic genetic entities, to rare syndromic multisystem diseases with optic atrophy such as mitochondrial encephalomyopathies, to age-related neurodegenerative diseases such as Alzheimer’s and Parkinson’s disease where optic nerve involvement has, until recently, been a relatively overlooked feature. New tools are available to thoroughly investigate optic nerve function, allowing unparalleled access to this part of the central nervous system. Understanding the molecular pathophysiology of RGC neurodegeneration and optic atrophy, is key to broadly understanding the pathogenesis of neurodegenerative disorders, for monitoring their progression in describing the natural history, and ultimately as outcome measures to evaluate therapies. In this review, the different layers, from molecular to anatomical, that may contribute to RGC neurodegeneration and optic atrophy are tackled in an integrated way, considering all relevant players. These include RGC dendrites, cell bodies and axons, the unmyelinated retinal nerve fiber layer and the myelinated post-laminar axons, as well as olygodendrocytes and astrocytes, looked for unconventional functions. Dysfunctional mitochondrial dynamics, transport, homeostatic control of mitobiogenesis and mitophagic removal, as well as specific propensity to apoptosis may target differently cell types and anatomical settings. Ultimately, we can envisage new investigative approaches and therapeutic options that will speed the early diagnosis of neurodegenerative diseases and their cure. PMID:28977448

Isolated optic nerve gliomas: a multicenter historical cohort study.

Science.gov (United States)

Shofty, Ben; Ben-Sira, Liat; Kesler, Anat; Jallo, George; Groves, Mari L; Iyer, Rajiv R; Lassaletta, Alvaro; Tabori, Uri; Bouffet, Eric; Thomale, Ulrich-Wilhelm; Hernáiz Driever, Pablo; Constantini, Shlomi

2017-12-01

OBJECTIVE Isolated optic nerve gliomas (IONGs) constitute a rare subgroup of optic pathway gliomas (OPGs). Due to the rarity of this condition and the difficulty in differentiating IONGs from other types of OPGs in most clinical series, little is known about these tumors. Currently, due to lack of evidence, they are managed the same as any other OPG. METHODS The authors conducted a multicenter retrospective cohort study aimed at determining the natural history of IONGs. Included were patients with clear-cut glioma of the optic nerve without posterior (chiasmatic/hypothalamic) involvement. At least 1 year of follow-up, 2 MRI studies, and 2 neuro-ophthalmological examinations were required for inclusion. RESULTS Thirty-six patients with 39 tumors were included in this study. Age at diagnosis ranged between 6 months and 16 years (average 6 years). The mean follow-up time was 5.6 years. Twenty-five patients had neurofibromatosis Type 1. During the follow-up period, 59% of the tumors progressed, 23% remained stable, and 18% (all with neurofibromatosis Type 1) displayed some degree of spontaneous regression. Fifty-one percent of the patients presented with visual decline, of whom 90% experienced further deterioration. Nine patients were treated with chemotherapy, 5 of whom improved visually. Ten patients underwent operation, and no local or distal recurrence was noted. CONCLUSIONS Isolated optic nerve gliomas are highly dynamic tumors. Radiological progression and visual deterioration occur in greater percentages than in the general population of patients with OPGs. Response to chemotherapy may be better in this group, and its use should be considered early in the course of the disease.

X-ray bang-time and fusion reaction history at ∼ ps resolution using RadOptic detection

International Nuclear Information System (INIS)

Vernon, S.P.; Lowry, M.E.; Baker, K.L.; Bennett, C.V.; Celeste, J.R.; Cerjan, C.; Haynes, S.; Hernandez, V.J.; Hsing, W.W.; London, R.A.; Moran, B.; von Wittenau, A.S.; Steele, P.T.; Stewart, R.E.

2012-01-01

We report recent progress in the development of RadOptic detectors, radiation to optical converters, that rely upon x-ray absorption induced modulation of the optical refractive index of a semiconductor sensor medium to amplitude modulate an optical probe beam. The sensor temporal response is determined by the dynamics of the electron-hole pair creation and subsequent relaxation in the sensor medium. Response times of a few ps have been demonstrated in a series of experiments conducted at the LLNL Jupiter Laser Facility. This technology will enable x-ray bang-time and fusion burn-history measurements with ∼ ps resolution.

New organic materials for optics: optical storage and nonlinear optics

International Nuclear Information System (INIS)

Gan, F.

1996-01-01

New organic materials have received considerable attention recently, due to their easy preparation and different variety. The most application fields in optics are optical storage and nonlinear optics. In optical storage the organic dyes have been used for example, in record able and erasable compact disks (CD-R, CD-E) nonlinear optical effects, such as nonlinear optical absorption, second and third order optical absorption, second and third order optical nonlinearities, can be applied for making optical limiters, optical modulators, as well as laser second and third harmonic generations. Due to high value of optical absorption and optical nonlinearity organic materials are always used as thin films in optical integration. In this paper the new experimental results have been presented, and future development has been also discussed. (author)

Research program in elementary particle theory: Progress report, January 1, 1987-December 1987

International Nuclear Information System (INIS)

Sudarshan, E.C.G.; Dicus, D.A.

1987-08-01

Progress is reported in the areas of: strings and gauge theories, mathematical physics and quantum optics, high energy physics phenomenology, quantum chromodynamic sum rules, and application of particle physics to astrophysics. Titles of DOE reports resulting from this research are listed, and the research histories of the scientific staff of the Center for Particle Theory are given

Pneumosinus dilatans of the spheno-ethmoidal complex associated with hypovitaminosis D causing bilateral optic canal stenosis.

Science.gov (United States)

Aryan, Saritha; Thakar, Sumit; Jagannatha, Aniruddha T; Channegowda, Chandrakiran; Rao, Arun S; Hegde, Alangar S

2017-06-01

Pneumosinus dilatans (PSD) is a rare disorder of undetermined etiology characterized by expansion of the paranasal sinuses without bony erosion. Of the few cases of PSD described in indexed pediatric literature, there has been no reported case of this disorder presenting with optic canal stenosis in the setting of a vitamin deficiency. A 12-year-old girl presented with a 3-month history of progressive, painless, and asymmetric visual deterioration in her eyes. MRI showed prominent perioptic CSF spaces bilaterally and mild atrophy of both the optic nerves. CT head showed hyperpneumatization of the sphenoethmoidal air cells and both anterior clinoid processes with the optic nerves contained within narrowed intact bony canals. Blood investigations showed reduced vitamin D levels, and a subsequent skeletal survey showed diffuse osteopenia. She underwent endoscopic sphenoidotomy and bilateral decompression of the optic nerves. Following surgery, she reported improvement of vision in her left eye. She was started on vitamin D supplements for the endocrine abnormality. At a follow-up visit 6 months later, her visual acuity in both her eyes had improved. Pneumosinus dilatans is an unusual cause of progressive optic nerve dysfunction in the pediatric population. In the absence of any associated intracranial pathologies, conditions like hypovitamosis D should be ruled out.

Efficient optical trapping of CdTe quantum dots by femtosecond laser pulses

KAUST Repository

Chiang, Weiyi

2014-12-11

The development in optical trapping and manipulation has been showing rapid progress, most of it is in the small particle sizes in nanometer scales, substituting the conventional continuous-wave lasers with high-repetition-rate ultrashort laser pulse train and nonlinear optical effects. Here, we evaluate two-photon absorption in optical trapping of 2.7 nm-sized CdTe quantum dots (QDs) with high-repetition-rate femtosecond pulse train by probing laser intensity dependence of both Rayleigh scattering image and the two-photon-induced luminescence spectrum of the optically trapped QDs. The Rayleigh scattering imaging indicates that the two-photon absorption (TPA) process enhances trapping ability of the QDs. Similarly, a nonlinear increase of the two-photon-induced luminescence with the incident laser intensity fairly indicates the existence of the TPA process.

Retinal and Optic Nerve Degeneration in Patients with Multiple Sclerosis Followed up for 5 Years.

Science.gov (United States)

Garcia-Martin, Elena; Ara, Jose R; Martin, Jesus; Almarcegui, Carmen; Dolz, Isabel; Vilades, Elisa; Gil-Arribas, Laura; Fernandez, Francisco J; Polo, Vicente; Larrosa, Jose M; Pablo, Luis E; Satue, Maria

2017-05-01

To quantify retinal nerve fiber layer (RNFL) changes in patients with multiple sclerosis (MS) and healthy controls with a 5-year follow-up and to analyze correlations between disability progression and RNFL degeneration. Observational and longitudinal study. One hundred patients with relapsing-remitting MS and 50 healthy controls. All participants underwent a complete ophthalmic and electrophysiologic exploration and were re-evaluated annually for 5 years. Visual acuity (Snellen chart), color vision (Ishihara pseudoisochromatic plates), visual field examination, optical coherence tomography (OCT), scanning laser polarimetry (SLP), and visual evoked potentials. Expanded Disability Status Scale (EDSS) scores, disease duration, treatments, prior optic neuritis episodes, and quality of life (QOL; based on the 54-item Multiple Sclerosis Quality of Life Scale score). Optical coherence tomography (OCT) revealed changes in all RNFL thicknesses in both groups. In the MS group, changes were detected in average thickness and in the mean deviation using the GDx-VCC nerve fiber analyzer (Laser Diagnostic Technologies, San Diego, CA) and in the P100 latency of visual evoked potentials; no changes were detected in visual acuity, color vision, or visual fields. Optical coherence tomography showed greater differences in the inferior and temporal RNFL thicknesses in both groups. In MS patients only, OCT revealed a moderate correlation between the increase in EDSS and temporal and superior RNFL thinning. Temporal RNFL thinning based on OCT results was correlated moderately with decreased QOL. Multiple sclerosis patients exhibit a progressive axonal loss in the optic nerve fiber layer. Retinal nerve fiber layer thinning based on OCT results is a useful marker for assessing MS progression and correlates with increased disability and reduced QOL. Copyright © 2017 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

Adaptive optics improves multiphoton super-resolution imaging

Science.gov (United States)

Zheng, Wei; Wu, Yicong; Winter, Peter; Shroff, Hari

2018-02-01

Three dimensional (3D) fluorescence microscopy has been essential for biological studies. It allows interrogation of structure and function at spatial scales spanning the macromolecular, cellular, and tissue levels. Critical factors to consider in 3D microscopy include spatial resolution, signal-to-noise (SNR), signal-to-background (SBR), and temporal resolution. Maintaining high quality imaging becomes progressively more difficult at increasing depth (where optical aberrations, induced by inhomogeneities of refractive index in the sample, degrade resolution and SNR), and in thick or densely labeled samples (where out-of-focus background can swamp the valuable, in-focus-signal from each plane). In this report, we introduce our new instrumentation to address these problems. A multiphoton structured illumination microscope was simply modified to integrate an adpative optics system for optical aberrations correction. Firstly, the optical aberrations are determined using direct wavefront sensing with a nonlinear guide star and subsequently corrected using a deformable mirror, restoring super-resolution information. We demonstrate the flexibility of our adaptive optics approach on a variety of semi-transparent samples, including bead phantoms, cultured cells in collagen gels and biological tissues. The performance of our super-resolution microscope is improved in all of these samples, as peak intensity is increased (up to 40-fold) and resolution recovered (up to 176+/-10 nm laterally and 729+/-39 nm axially) at depths up to 250 μm from the coverslip surface.

Progress of inflammatory cytokines in glaucoma

Directory of Open Access Journals (Sweden)

Ping Hu

2015-12-01

Full Text Available Glaucomais a group of diseases characterized by optic nerve damage and visual field defect, and pathological high intraocular pressure is a risk factor for glaucoma. Glaucoma is affected by the interaction of multiple genes and environmental factors, and inflammation may be involved in the pathogenesis of glaucoma. A great deal of studies have confirmed that high expression of connective tissue growth factor(CTGF, tumor necrosis factor-α(TNF-α, interleukins(ILs, nuclear factor-kappa B(NF-κBand various cytokines in the aqueous humor of patients with glaucoma, which have a close correlation with pathogenesis of glaucoma.This article reviews the progress of inflammatory cytokines and their relationship with glaucoma.

Towards three-dimensional optical metamaterials

Science.gov (United States)

Tanaka, Takuo; Ishikawa, Atsushi

2017-12-01

Metamaterials have opened up the possibility of unprecedented and fascinating concepts and applications in optics and photonics. Examples include negative refraction, perfect lenses, cloaking, perfect absorbers, and so on. Since these metamaterials are man-made materials composed of sub-wavelength structures, their development strongly depends on the advancement of micro- and nano-fabrication technologies. In particular, the realization of three-dimensional metamaterials is one of the big challenges in this research field. In this review, we describe recent progress in the fabrication technologies for three-dimensional metamaterials, as well as proposed applications.

A case of radiation optic neuropathy after irradiation for pituitary adenoma

Energy Technology Data Exchange (ETDEWEB)

Ohta, Masahiro; Sasaki, Ushio; Shinohara, Nobuya; Takeda, Tetsuji; Chaki, Takanori; Nishigakiuchi, Keiji; Kusunoki, Katsusuke (Ehime Prefectural Central Hospital, Matsuyama (Japan))

1992-05-01

A 60-year-old woman with radiation optic neuropathy 21 months after irradiation is reported. The patient received a total dose of 50 Gy in 25 fractions for 39 days for pituitary adenoma. She presented with bitemporal hemianopsia and loss of recent memory. Gadolinium-enhanced T1-weighted imaging was very useful for detecting lesions in the optic nerves and chiasm to the hypothalamus including mamillary bodies. Two-month steroid therapy was effective in preventing the disease progression, although visual loss and loss of recent memory were not improved. (N.K.).

A case of radiation optic neuropathy after irradiation for pituitary adenoma

International Nuclear Information System (INIS)

Ohta, Masahiro; Sasaki, Ushio; Shinohara, Nobuya; Takeda, Tetsuji; Chaki, Takanori; Nishigakiuchi, Keiji; Kusunoki, Katsusuke

1992-01-01

A 60-year-old woman with radiation optic neuropathy 21 months after irradiation is reported. The patient received a total dose of 50 Gy in 25 fractions for 39 days for pituitary adenoma. She presented with bitemporal hemianopsia and loss of recent memory. Gadolinium-enhanced T1-weighted imaging was very useful for detecting lesions in the optic nerves and chiasm to the hypothalamus including mamillary bodies. Two-month steroid therapy was effective in preventing the disease progression, although visual loss and loss of recent memory were not improved. (N.K.)

Laboratory Directed Research and Development FY 2000 Annual Progress Report

Energy Technology Data Exchange (ETDEWEB)

Los Alamos National Laboratory

2001-05-01

This is the FY00 Annual Progress report for the Laboratory Directed Research and Development (LDRD) Program at Los Alamos National Laboratory. It gives an overview of the LDRD Program, summarizes progress on each project conducted during FY00, characterizes the projects according to their relevance to major funding sources, and provides an index to principal investigators. Project summaries are grouped by LDRD component: Directed Research and Exploratory Research. Within each component, they are further grouped into the ten technical categories: (1) atomic, molecular, optical, and plasma physics, fluids, and beams, (2) bioscience, (3) chemistry, (4) computer science and software engineering, (5) engineering science, (6) geoscience, space science, and astrophysics, (7) instrumentation and diagnostics, (8) materials science, (9) mathematics, simulation, and modeling, and (10) nuclear and particle physics.

Combined Yb/Nd driver for optical parametric chirped pulse amplifiers.

Science.gov (United States)

Michailovas, Kirilas; Baltuska, Andrius; Pugzlys, Audrius; Smilgevicius, Valerijus; Michailovas, Andrejus; Zaukevicius, Audrius; Danilevicius, Rokas; Frankinas, Saulius; Rusteika, Nerijus

2016-09-19

We report on the developed front-end/pump system for optical parametric chirped pulse amplifiers. The system is based on a dual output fiber oscillator/power amplifier which seeds and assures all-optical synchronization of femtosecond Yb and picosecond Nd laser amplifiers operating at a central wavelength of 1030 nm and 1064 nm, respectively. At the central wavelength of 1030 nm, the fiber oscillator generates partially stretched 4 ps pulses with the spectrum supporting a scaling currently is prevented by limited dimensions of the diffraction gratings, which, because of the fast progress in MLD grating manufacturing technologies is only a temporary obstacle.

Progress in complementary metal–oxide–semiconductor silicon photonics and optoelectronic integrated circuits

International Nuclear Information System (INIS)

Chen Hongda; Zhang Zan; Huang Beiju; Mao Luhong; Zhang Zanyun

2015-01-01

Silicon photonics is an emerging competitive solution for next-generation scalable data communications in different application areas as high-speed data communication is constrained by electrical interconnects. Optical interconnects based on silicon photonics can be used in intra/inter-chip interconnects, board-to-board interconnects, short-reach communications in datacenters, supercomputers and long-haul optical transmissions. In this paper, we present an overview of recent progress in silicon optoelectronic devices and optoelectronic integrated circuits (OEICs) based on a complementary metal–oxide–semiconductor-compatible process, and focus on our research contributions. The silicon optoelectronic devices and OEICs show good characteristics, which are expected to benefit several application domains, including communication, sensing, computing and nonlinear systems. (review)

Quantitative measurements in laser induced plasmas using optical probing. Progress report, October 1, 1977--April 30, 1978

International Nuclear Information System (INIS)

Sweeney, D.W.

1978-06-01

Optical probing of laser induced plasmas can be used to quantitatively reconstruct electron number densities and magnetic fields. Numerical techniques for extracting quantitative information from the experimental data are described and four Abel inversion codes are provided. A computer simulation of optical probing is used to determine the quantitative information that can be reasonably extracted from real experimental systems. Examples of reconstructed electron number densities from interferograms of laser plasmas show steepened electron distributions

Sources of polarized negative ions: progress and prospects

International Nuclear Information System (INIS)

Haeberli, W.

1980-01-01

A summary of recent progress in the art of producing beams of polarized ions is given. In all sources of polarized ions, one first produces (or selects) neutral atoms which are polarized in electron spin. Those types of sources which use a beam of thermal polarized hydrogen atoms are discussed. Progress made in the preparation of the atomic beam and the methods used to convert the neutral atoms to polarized ions is summarized. The second type of source discussed is based on fast (keV) polarized hydrogen atoms. Conversion to negative ions is very simple because one only needs to pass the fast atoms through a suitable charge exchange medium (gas or vapor). However, the production of the polarized atoms is more difficult in this case. The proposal to employ polarized alkali vapor to form a beam of polarized fast H atoms, where the polarized alkali atoms are produced either by an atomic beam apparatus or by optical pumping is discussed

Novel concepts in near-field optics: from magnetic near-field to optical forces

Science.gov (United States)

Yang, Honghua

Driven by the progress in nanotechnology, imaging and spectroscopy tools with nanometer spatial resolution are needed for in situ material characterizations. Near-field optics provides a unique way to selectively excite and detect elementary electronic and vibrational interactions at the nanometer scale, through interactions of light with matter in the near-field region. This dissertation discusses the development and applications of near-field optical imaging techniques, including plasmonic material characterization, optical spectral nano-imaging and magnetic field detection using scattering-type scanning near-field optical microscopy (s-SNOM), and exploring new modalities of optical spectroscopy based on optical gradient force detection. Firstly, the optical dielectric functions of one of the most common plasmonic materials---silver is measured with ellipsometry, and analyzed with the Drude model over a broad spectral range from visible to mid-infrared. This work was motivated by the conflicting results of previous measurements, and the need for accurate values for a wide range of applications of silver in plasmonics, optical antennas, and metamaterials. This measurement provides a reference for dielectric functions of silver used in metamaterials, plasmonics, and nanophotonics. Secondly, I implemented an infrared s-SNOM instrument for spectroscopic nano-imaging at both room temperature and low temperature. As one of the first cryogenic s-SNOM instruments, the novel design concept and key specifications are discussed. Initial low-temperature and high-temperature performances of the instrument are examined by imaging of optical conductivity of vanadium oxides (VO2 and V2O 3) across their phase transitions. The spectroscopic imaging capability is demonstrated on chemical vibrational resonances of Poly(methyl methacrylate) (PMMA) and other samples. The third part of this dissertation explores imaging of optical magnetic fields. As a proof-of-principle, the magnetic

IOTA (Integrable Optics Test Accelerator): facility and experimental beam physics program

Science.gov (United States)

Antipov, S.; Broemmelsiek, D.; Bruhwiler, D.; Edstrom, D.; Harms, E.; Lebedev, V.; Leibfritz, J.; Nagaitsev, S.; Park, C. S.; Piekarz, H.; Piot, P.; Prebys, E.; Romanov, A.; Ruan, J.; Sen, T.; Stancari, G.; Thangaraj, C.; Thurman-Keup, R.; Valishev, A.; Shiltsev, V.

2017-03-01

The Integrable Optics Test Accelerator (IOTA) is a storage ring for advanced beam physics research currently being built and commissioned at Fermilab. It will operate with protons and electrons using injectors with momenta of 70 and 150 MeV/c, respectively. The research program includes the study of nonlinear focusing integrable optical beam lattices based on special magnets and electron lenses, beam dynamics of space-charge effects and their compensation, optical stochastic cooling, and several other experiments. In this article, we present the design and main parameters of the facility, outline progress to date and provide the timeline of the construction, commissioning and research. The physical principles, design, and hardware implementation plans for the major IOTA experiments are also discussed.

IOTA (Integrable Optics Test Accelerator): Facility and experimental beam physics program

International Nuclear Information System (INIS)

Antipov, Sergei; Broemmelsiek, Daniel; Bruhwiler, David; Edstrom, Dean; Harms, Elvin

2017-01-01

The Integrable Optics Test Accelerator (IOTA) is a storage ring for advanced beam physics research currently being built and commissioned at Fermilab. It will operate with protons and electrons using injectors with momenta of 70 and 150 MeV/c, respectively. The research program includes the study of nonlinear focusing integrable optical beam lattices based on special magnets and electron lenses, beam dynamics of space-charge effects and their compensation, optical stochastic cooling, and several other experiments. In this article, we present the design and main parameters of the facility, outline progress to date and provide the timeline of the construction, commissioning and research. Finally, the physical principles, design, and hardware implementation plans for the major IOTA experiments are also discussed.

Optical properties of amyloid stained by Congo red: history and mechanisms.

Science.gov (United States)

Howie, Alexander J; Brewer, Douglas B

2009-04-01

Amyloid stained by Congo red has striking optical properties that generally have been poorly described and inadequately explained, although they can be understood from principles of physical optics. Molecules of Congo red are orientated on amyloid fibrils, and so the dye becomes dichroic and birefringent. The birefringence varies with wavelength in accordance with a fundamental property of all light-transmitting materials called anomalous dispersion of the refractive index around an absorption peak. The combination of this and absorption of light, with modification by any additional birefringence in the optical system, explains the various colours that can be seen in Congo red-stained amyloid between crossed polariser and analyser, and also when the polariser and analyser are progressively uncrossed. These are called anomalous colours.

Bilateral Glaucomatous Optic Neuropathy Caused by Eye Rubbing.

Science.gov (United States)

Savastano, Alfonso; Savastano, Maria Cristina; Carlomusto, Laura; Savastano, Silvio

2015-01-01

In this report, we describe a particular condition of a 52-year-old man who showed advanced bilateral glaucomatous-like optic disc damage, even though the intraocular pressure resulted normal during all examinations performed. Visual field test, steady-state pattern electroretinogram, retinal nerve fiber layer and retinal tomographic evaluations were performed to evaluate the optic disc damage. Over a 4-year observational period, his visual acuity decreased to 12/20 in the right eye and counting fingers in the left eye. Visual fields were severely compromised, and intraocular pressure values were not superior to 14 mm Hg during routine examinations. An accurate anamnesis and the suspicion of this disease represent a crucial aspect to establish the correct diagnosis. In fact, our patient strongly rubbed his eyes for more than 10 h per day. Recurrent and continuous eye rubbing can induce progressive optic neuropathy, causing severe visual field damage similar to the pathology of advanced glaucoma.

Soft optics in intelligent optical networks

Science.gov (United States)

Shue, Chikong; Cao, Yang

2001-10-01

In addition to the recent advances in Hard-optics that pushes the optical transmission speed, distance, wave density and optical switching capacity, Soft-optics provides the necessary intelligence and control software that reduces operational costs, increase efficiency, and enhances revenue generating services by automating optimal optical circuit placement and restoration, and enabling value-added new services like Optical VPN. This paper describes the advances in 1) Overall Hard-optics and Soft-optics 2) Layered hierarchy of Soft-optics 3) Component of Soft-optics, including hard-optics drivers, Management Soft-optics, Routing Soft-optics and System Soft-optics 4) Key component of Routing and System Soft-optics, namely optical routing and signaling (including UNI/NNI and GMPLS signaling). In summary, the soft-optics on a new generation of OXC's enables Intelligent Optical Networks to provide just-in-time service delivery and fast restoration, and real-time capacity management that eliminates stranded bandwidth. It reduces operational costs and provides new revenue opportunities.

Optics vs copper: from the perspective of "Thunderbolt" interconnect technology

Science.gov (United States)

Cheng, Hengju; Krause, Christine; Ko, Jamyuen; Gao, Miaobin; Liu, Guobin; Wu, Huichin; Qi, Mike; Lam, Chun-Chit

2013-02-01

Interconnect technology has been progressed at a very fast pace for the past decade. The signaling rates have steadily increased from 100:Mb/s to 25Gb/s. In every generation of interconnect technology evolution, optics always seems to take over at first, however, at the end, the cost advantage of copper wins over. Because of this, optical interconnects are limited to longer distance links where the attenuation in copper cable is too large for the integrated circuits to compensate. Optical interconnect has long been viewed as the premier solution in compared with copper interconnect. With the release of Thunderbolt technology, we are entering a new era in consumer electronics that runs at 10Gb/s line rate (20Gb/s throughput per connector interface). Thunderbolt interconnect technology includes both active copper cables and active optical cables as the transmission media which have very different physical characteristics. In order for optics to succeed in consumer electronics, several technology hurdles need to be cleared. For example, the optical cable needs to handle the consumer abuses such as pinch and bend. Also, the optical engine used in the active optical cable needs to be physically very small so that we don't change the looks and feels of the cable/connector. Most importantly, the cost of optics needs to come down significantly to effectively compete with the copper solution. Two interconnect technologies are compared and discussed on the relative cost, power consumption, form factor, density, and future scalability.

Applications of optical sensors for high-frequency water-quality monitoring and research

Science.gov (United States)

Pellerin, Brian

2015-01-01

The recent commercial availability of in-situ optical sensors, together with new techniques for data collection and analysis, provides the opportunity to monitor a wide range of water-quality constituents over time scales during which environmental conditions actually change. Traditional approaches for data collection (daily to monthly discrete samples) are often limited by high sample collection, processing, and analytical costs, difficult site access, and logistical challenges, particularly for long-term sampling at a large number of sites. Optical sensors that continuously measure constituents in the environment by absorbance or fluorescence properties (Figure 1) have had a long history of use in oceanography for measuring highly resolved concentrations and fluxes of organic matter, nutrients, and algal material. However, much of the work using commercially-available optical sensors in rivers and streams has taken place in only the last few years. Figure 1. [NOT SHOWN] Optical sensor technology is now sufficiently developed to warrant broader application for research and monitoring in coastal and freshwater systems, and the United States Geological Survey (a U.S. science agency) is now using these sensors in a variety of research and monitoring programs to better understand water quality in-situ and in real-time. Examples are numerous and range from the applications of nitrate sensors for calculating loads to estuaries susceptible to hypoxia (Pellerin et al., 2014) to the use of fluorometers to estimate methymercury fluxes (Bergamaschi et al., 2011) and disinfection byproduct formation (Carpenter et al., 2013). Transmitting these data in real-time provides information that can be used for early trend detection, help identify monitoring gaps critical for water management, and provide science-based decision support across a range of issues related to water quality, freshwater ecosystems, and human health. Despite the value of these sensors, collecting data that

Optical Astronomy in Post-Apartheid South Africa: 1994 to 2004

Science.gov (United States)

Whitelock, P. A.

2004-10-01

The progress of optical astronomy in post-apartheid South Africa is discussed. Particular emphasis is given to the socio-political climate which embraced the idea of a 10-m class telescope as a flagship project that would lead to widespread development in science, technology and education - not only in South Africa, but across the subcontinent.

Atomic and molecular spectroscopy with optical-frequency-comb-referenced IR coherent sources

International Nuclear Information System (INIS)

Cancio, P.; Bartalini, S.; De Rosa, M.; Giusfredi, G.; Mazzotti, D.; Maddaloni, P.; Vitiello, M. S.; De Natale, P.

2013-01-01

We provide a review of progress in the development of metrological-grade measurements in atomic and molecular systems through the extension, in the mid-infrared and far-infrared range, of optical frequency combs (OFCs) and the introduction of new techniques and highly coherent sources. (authors)

Application of optical coherence tomography attenuation imaging for quantification of optical properties in medulloblastoma

Science.gov (United States)

Vuong, Barry; Skowron, Patryk; Kiehl, Tim-Rasmus; Kyan, Matthew; Garzia, Livia; Genis, Helen; Sun, Cuiru; Taylor, Michael D.; Yang, Victor X. D.

2015-03-01

The hemodynamic environment is known to play a crucial role in the progression, rupture, and treatment of intracranial aneurysms. Currently there is difficulty assessing and measuring blood flow profiles in vivo. An emerging high resolution imaging modality known as split spectrum Doppler optical coherence tomography (ssDOCT) has demonstrated the capability to quantify hemodynamic patterns as well as arterial microstructural changes. In this study, we present a novel in vitro method to acquire precise blood flow patterns within a patient- specific aneurysm silicone flow models using ssDOCT imaging. Computational fluid dynamics (CFD) models were generated to verify ssDOCT results.

Late-onset progressive visual loss in a man with unusual MRI findings: MS, Harding's, Leber's or Leber's Plus?

LENUS (Irish Health Repository)

Cawley, N

2012-02-01

Leber\\'s hereditary optic neuropathy (LHON) is a maternally inherited disorder, typically presenting in the second and third decade. We report the case of an elderly gentleman with significant vascular risk factors, presenting with slowly progressive, bilateral, visual loss with high signal lesions in the pericallosal and periventricular deep white matter on MRI brain studies. Possible diagnoses included late-onset MS, ischaemic optic neuropathies, a mitochondrial disorder or an overlap syndrome such as Harding\\'s disease.

Research Progress and Development of Sapphire Fiber Sensor

Directory of Open Access Journals (Sweden)

Guochang ZHAO

2014-07-01

Full Text Available Sapphire fiber thermometers have become a new potential option in the field of high-temperature measurements. Recent research progress of sapphire fiber sensors is summarized; operational principles, advantages, disadvantages, and applications of sapphire fiber sensors are introduced. Research has shown that sapphire fiber sensors can be used to accurately measure very high temperatures in harsh environments and has been widely applied in fields such as aviation, metallurgy, the chemical industry, energy, and other high temperature measurement areas. Sapphire optical fiber temperature measurement technology will move toward miniaturization, intelligence following the advances in materials, micro-fabrication and communication technologies.

Recent Progress in the Study of Topological Semimetals

Science.gov (United States)

Bernevig, Andrei; Weng, Hongming; Fang, Zhong; Dai, Xi

2018-04-01

The topological semimetal is a new, theoretically predicted and experimentally discovered, topological state of matter. In one of its several realizations, the topological semimetal hosts Weyl fermions, elusive particles predicted more than 85 years ago, sought after in high-energy experiments, but only recently found in a condensed-matter setting. In the present review, we catalogue the most recent progress in this fast-developing research field. We give special attention to topological invariants and the material realization of three different types of topological semimetal. We also discuss various photo emission, transport and optical experimental observables that characterize the appearance of topological semimetal phases.

Present status of metrology of electro-optical surveillance systems

Science.gov (United States)

Chrzanowski, K.

2017-10-01

There has been a significant progress in equipment for testing electro-optical surveillance systems over the last decade. Modern test systems are increasingly computerized, employ advanced image processing and offer software support in measurement process. However, one great challenge, in form of relative low accuracy, still remains not solved. It is quite common that different test stations, when testing the same device, produce different results. It can even happen that two testing teams, while working on the same test station, with the same tested device, produce different results. Rapid growth of electro-optical technology, poor standardization, limited metrology infrastructure, subjective nature of some measurements, fundamental limitations from laws of physics, tendering rules and advances in artificial intelligence are major factors responsible for such situation. Regardless, next decade should bring significant improvements, since improvement in measurement accuracy is needed to sustain fast growth of electro-optical surveillance technology.

Center for X-Ray Optics, 1986

International Nuclear Information System (INIS)

1987-07-01

The Center for X-Ray Optics has made substantial progress during the past year on the development of very high resolution x-ray technologies, the generation of coherent radiation at x-ray wavelengths, and, based on these new developments, had embarked on several scientific investigations that would not otherwise have been possible. The investigations covered in this report are topics on x-ray sources, x-ray imaging and applications, soft x-ray spectroscopy, synchrotron radiation, advanced light source and magnet structures for undulators and wigglers

Cultivation mode research of practical application talents for optical engineering major

Science.gov (United States)

Liu, Zhiying

2017-08-01

The requirements on science and technology graduates are more and higher with modern science progress and society market economy development. Because optical engineering major is with very long practicality, practice should be paid more attention from analysis of optical engineering major and students' foundation. To play role of practice to a large amount, the practice need be systemic and correlation. It should be combination of foundation and profundity. Modern foundation professional knowledge is studied with traditional optical concept and technology at the same time. Systemic regularity and correlation should be embodied in the contents. Start from basic geometrical optics concept, the optical parameter of optical instrument is analyzed, the optical module is built and ray tracing is completed during geometrical optics practice. With foundation of primary aberration calculation, the optical system is further designed and evaluated during optical design practice course. With the optical model and given instrument functions and requirements, the optical-mechanism is matched. The accuracy is calculated, analyzed and distributed in every motion segment. And the mechanism should guarantee the alignment and adjustment. The optical mechanism is designed during the instrument and element design practice. When the optical and mechanism drawings are completed, the system is ready to be fabricated. Students can complete grinding, polishing and coating process by themselves through optical fabricating practice. With the optical and mechanical elements, the system can be assembled and aligned during the thesis practice. With a set of correlated and logical practices, the students can acquire the whole process knowledge about optical instrument. All details are contained in every practice process. These practical experiences provide students working ability. They do not need much adaption anymore when they go to work after graduation. It is favorable to both student

SBIR Final Report. Liquid Core Optical Scintillating Fibers

International Nuclear Information System (INIS)

Beetz, C.P.; Steinbeck, J.; Buerstler, R.

2000-01-01

This Phase I SBIR project focused on developing flexible scintillating liquid core optical fibers, with potential uses in high-energy calorimetry, tracking, preradiators, active targets or other fast detectors. Progress on the six tasks of the project is summarized. The technical developments involve three technology components: (1) highly flexible capillaries or tubes of relatively low n (index of refraction) to serve as cladding and liquid core containment; (2) scintillator (and clear) fluids of relatively high n to serve as a core-- these fluids must have a high light transmission and, for some applications, radiation hardness; (3) optical end plugs, plug insertion, and plug-cladding tube sealing technology to contain the core fluids in the tubes, and to transmit the light

Alteration in ocular blood flow and its effect on the progression of glaucoma

Directory of Open Access Journals (Sweden)

Sher Zaman Safi

2017-04-01

Full Text Available Glaucoma is a multifactorial neurodegenerative disease that can result in permanent vision loss by damaging optic nerves due to higher pressure in the eye. Although most of the fundamental pathophysiological mechanisms involved in glaucoma are undetermined but alteration in ocular blood flow(OBFin tissues such as optic nerve, retina, choroid and iris is an important risk factor for glaucoma. Various factors such as limited knowledge of the factors causing optic nerve damage, confusion in the measurement assays and lack of therapies, make hindrances in the understanding of glaucoma. Researchers are continuously accumulating evidence to suggest that alterations in OBF play important role in the pathogenesis of glaucoma but most of the times they have diverse and contradictory conclusions regarding changes in the OBF and risk of glaucoma. In this article we have reviewed different aspects of glaucoma and the effect of OBF in the disease progression

Radiation effects on optical components of a laser radar sensor designed for remote metrology in ITER

International Nuclear Information System (INIS)

Menon, M.M.; Grann, E.B.; Slotwinski, A.

1997-09-01

A frequency modulated laser radar is being developed for in-vessel metrology and viewing of plasma-facing surfaces. Some optical components of this sensor must withstand intense gamma radiation (3 x 10 6 rad/h) during operation. The authors have tested the effect of radiation on a silica core polarization maintaining optical fiber and on TeO 2 crystals at doses up to ∼ 10 9 rad. Additional tests are planned for evaluating the performance of a complete acousto-optic (AO) scanning device. The progress made in these tests is also described

At-wavelength metrology of x-ray optics at Diamond Light Source

Science.gov (United States)

Wang, Hongchang; Berujon, Sebastien; Sutter, John; Alcock, Simon G.; Sawhney, Kawal

2014-09-01

Modern, third-generation synchrotron radiation sources provide coherent and extremely bright beams of X-ray radiation. The successful exploitation of such beams depends to a significant extent on imperfections and misalignment of the optics employed on the beamlines. This issue becomes even more critical with the increasing use of active optics, and the desire to achieve diffraction-limited and coherence-preserving X-ray beams. In recent years, significant progress has been made to improve optic testing and optimization techniques, especially those using X-rays for so-called atwavelength metrology. These in-situ and at-wavelength metrology methods can be used not only to optimize the performance of X-ray optics, but also to correct and minimize the collective distortions of upstream beamline optics, including monochromators, and transmission windows. An overview of at-wavelength metrology techniques implemented at Diamond Light Source is presented, including grating interferometry and X-ray near-field speckle based techniques. Representative examples of the application of these techniques are also given, including in-situ and atwavelength calibration and optimization of: active, piezo bimorph mirrors; Kirkpatrick-Baez (KB) mirrors; and refractive optics such as compound refractive lenses.

An Optic Nerve Crush Injury Murine Model to Study Retinal Ganglion Cell Survival

Science.gov (United States)

Tang, Zhongshu; Zhang, Shuihua; Lee, Chunsik; Kumar, Anil; Arjunan, Pachiappan; Li, Yang; Zhang, Fan; Li, Xuri

2011-01-01

Injury to the optic nerve can lead to axonal degeneration, followed by a gradual death of retinal ganglion cells (RGCs), which results in irreversible vision loss. Examples of such diseases in human include traumatic optic neuropathy and optic nerve degeneration in glaucoma. It is characterized by typical changes in the optic nerve head, progressive optic nerve degeneration, and loss of retinal ganglion cells, if uncontrolled, leading to vision loss and blindness. The optic nerve crush (ONC) injury mouse model is an important experimental disease model for traumatic optic neuropathy, glaucoma, etc. In this model, the crush injury to the optic nerve leads to gradual retinal ganglion cells apoptosis. This disease model can be used to study the general processes and mechanisms of neuronal death and survival, which is essential for the development of therapeutic measures. In addition, pharmacological and molecular approaches can be used in this model to identify and test potential therapeutic reagents to treat different types of optic neuropathy. Here, we provide a step by step demonstration of (I) Baseline retrograde labeling of retinal ganglion cells (RGCs) at day 1, (II) Optic nerve crush injury at day 4, (III) Harvest the retinae and analyze RGC survival at day 11, and (IV) Representative result. PMID:21540827

Morphological functional criteria of neuroprotective therapy efficacy in glaucomatous optic neuropathy

Directory of Open Access Journals (Sweden)

Tszin Dan

2015-01-01

Full Text Available Electrophysiological tests may be used to detect early glaucomatous changes and glaucoma progression risk and to monitor treatment efficacy. Most important pathogenic aspects of glaucomatous process, pathogenesis and multifactorial nature of glaucomatous optic neuropathy are described. Major triggers of glaucomatous optic neuropathy are mechanical and vascular. Principles of neuroprotective therapy, neuroprotective drugs, and mechanisms of action of direct and indirect neuroprotective agents are presented. IOPcc is a basis for neuroprotective therapy selection and its efficacy monitoring. Amongst neuroprotective drugs, NMDA agonists, antioxidants, peptides, and calcium channel blockers are of special importance. Structural damage and functional deficiency (e.g., visual field loss in glaucoma and the most informative and accurate methods of their detection are characterized. Confocal laser microscopy, optical coherence tomography, and scanning laser polarimetry are compared. These techniques are used to study optic nerve head and retinal nerve fiber layer. They are proposed as diagnostic and monitoring tools for glaucoma, glaucoma suspicion, and ocular hypertension. The most sensitive and specific electrophysiological tests for glaucomatous optic neuropathy are pattern electroretinography, multfocal electroretinography, and multifocal visually evoked potentials. 

Optical Graphene Gas Sensors Based on Microfibers: A Review

Directory of Open Access Journals (Sweden)

Yu Wu

2018-03-01

Full Text Available Graphene has become a bridge across optoelectronics, mechanics, and bio-chemical sensing due to its unique photoelectric characteristics. Moreover, benefiting from its two-dimensional nature, this atomically thick film with full flexibility has been widely incorporated with optical waveguides such as fibers, realizing novel photonic devices including polarizers, lasers, and sensors. Among the graphene-based optical devices, sensor is one of the most important branch, especially for gas sensing, as rapid progress has been made in both sensing structures and devices in recent years. This article presents a comprehensive and systematic overview of graphene-based microfiber gas sensors regarding many aspects including sensing principles, properties, fabrication, interrogating and implementations.

DYNAMISM OF DOT SUBRETINAL DRUSENOID DEPOSITS IN AGE-RELATED MACULAR DEGENERATION DEMONSTRATED WITH ADAPTIVE OPTICS IMAGING.

Science.gov (United States)

Zhang, Yuhua; Wang, Xiaolin; Godara, Pooja; Zhang, Tianjiao; Clark, Mark E; Witherspoon, C Douglas; Spaide, Richard F; Owsley, Cynthia; Curcio, Christine A

2018-01-01

To investigate the natural history of dot subretinal drusenoid deposits (SDD) in age-related macular degeneration, using high-resolution adaptive optics scanning laser ophthalmoscopy. Six eyes of four patients with intermediate age-related macular degeneration were studied at baseline and 1 year later. Individual dot SDD within the central 30° retina were examined with adaptive optics scanning laser ophthalmoscopy and optical coherence tomography. A total of 269 solitary SDD were identified at baseline. Over 12.25 ± 1.18 months, all 35 Stage 1 SDD progressed to advanced stages. Eighteen (60%) Stage 2 lesions progressed to Stage 3 and 12 (40%) remained at Stage 2. Of 204 Stage 3 SDD, 12 (6.4%) disappeared and the rest remained. Twelve new SDD were identified, including 6 (50%) at Stage 1, 2 (16.7%) at Stage 2, and 4 (33.3%) at Stage 3. The mean percentage of the retina affected by dot SDD, measured by the adaptive optics scanning laser ophthalmoscopy, increased in 5/6 eyes (from 2.31% to 5.08% in the most changed eye) and decreased slightly in 1/6 eye (from 10.67% to 10.54%). Dynamism, the absolute value of the areas affected by new and regressed lesions, ranged from 0.7% to 9.3%. Adaptive optics scanning laser ophthalmoscopy reveals that dot SDD, like drusen, are dynamic.

Influence of the least-squares phase on optical vortices in strongly scintillated beams

CSIR Research Space (South Africa)

Chen, M

2009-06-01

Full Text Available , the average total number of vortices is reduced further. However, the reduction becomes smaller for each succes- sive step. This indicates that the ability of getting rid of optical vortices by removing the least-squares phase becomes progressively less...

Electrical and Optical Enhancement in Internally Nanopatterned Organic Light-Emitting Diodes

Science.gov (United States)

Fina, Michael Dane

Organic light-emitting diodes (OLEDs) have made tremendous technological progress in the past two decades and have emerged as a top competitor for next generation light-emitting displays and lighting. State-of-the-art OLEDs have been reported in literature to approach, and even surpass, white fluorescent tube efficiency. However, despite rapid technological progress, efficiency metrics must be improved to compete with traditional inorganic light-emitting diode (LED) technology. Organic materials possess specialized traits that permit manipulations to the light-emitting cavity. Overall, as demonstrated within, these modifications can be used to improve electrical and optical device efficiencies. This work is focused at analyzing the effects that nanopatterned geometric modifications to the organic active layers play on device efficiency. In general, OLED efficiency is complicated by the complex, coupled processes which contribute to spontaneous dipole emission. A composite of three sub-systems (electrical, exciton and optical) ultimately dictate the OLED device efficiency. OLED electrical operation is believed to take place via a low-mobility-modified Schottky injection process. In the injection-limited regime, geometric effects are expected to modify the local electric field leading to device current enhancement. It is shown that the patterning effect can be used to enhance charge carrier parity, thereby enhancing overall recombination. Current density and luminance characteristics are shown to be improved by OLED nanopatterning from both the model developed within and experimental techniques. Next, the optical enhancement effects produced by the nanopatterned array are considered. Finite-difference time-domain (FDTD) simulations are used to determine positional, spectral optical enhancement for the nanopatterned device. The results show beneficial effects to the device performance. The optical enhancements are related to the reduction in internal radiative

Recent progress on the Los Alamos Aurora ICF [inertial confinement fusion] laser system

International Nuclear Information System (INIS)

Rosocha, L.A.; Blair, L.S.

1987-01-01

Aurora is the Los Alamos short-pulse, high-power, krypton-fluoride laser system. It serves as an end-to-end technology demonstration prototype for large-scale ultraviolet laser systems for short wavelength inertial confinement fusion (ICF) investigations. The system is designed to employ optical angular multiplexing and serial amplification by electron-beam-driven KrF laser amplifiers to deliver stacked, 248-nm, 5-ns duration multikilojoule laser pulses to ICF-relevant targets. This paper presents a summary of the Aurora system and a discussion of the progress achieved in the construction and integration of the laser system. We concentrate on the main features of the following major system components: front-end lasers, amplifier train, multiplexer, optical relay train, demultiplexer, and the associated optical alignment system. During the past year, two major construction and integration tasks have been accomplished. The first task is the demonstration of 96-beam multiplexing and amplified energy extraction, as evidenced by the integrated operation of the front end, the multiplexer (12-fold and 8-fold encoders), the optical relay train, and three electron-beam-driven amplifiers. The second task is the assembly and installation of the demultiplexer optical hardware, which consists of over 300 optical components ranging in size from several centimeters square to over a meter square. 13 refs., 13 figs

Bilateral optic neuropathy in a patient with familial amyloidotic polyneuropathy

DEFF Research Database (Denmark)

Hamann, Steffen; Jensen, Peter Koch; Fledelius, Hans Callø

2013-01-01

Amyloidogenic transthyretin (ATTR)-related familial amyloidotic polyneuropathy (FAP) is an autosomal-dominant hereditary disease characterised by slowly progressive peripheral sensorimotor and autonomic neuropathy and tissue involvement of the heart, kidneys and central nervous system. Secondary...... ATTR Val30Met mutation. After 11 years of ophthalmic follow-up best-corrected visual acuity was 20/100 in his seeing eye, which further had visual field findings suggestive of optic neuropathy. This was also the diagnosis underlying the preceding insidious full loss of vision in the fellow eye......, with colour Doppler imaging to support an ischaemic aetiology. To our knowledge, this is the first report of ischaemic optic neuropathy in this familial amyloid disorder....

Optical diagnostics based on elastic scattering: Recent clinical demonstrations with the Los Alamos Optical Biopsy System

Energy Technology Data Exchange (ETDEWEB)

Bigio, I.J.; Loree, T.R.; Mourant, J.; Shimada, T. [Los Alamos National Lab., NM (United States); Story-Held, K.; Glickman, R.D. [Texas Univ. Health Science Center, San Antonio, TX (United States). Dept. of Ophthalmology; Conn, R. [Lovelace Medical Center, Albuquerque, NM (United States). Dept. of Urology

1993-08-01

A non-invasive diagnostic tool that could identify malignancy in situ and in real time would have a major impact on the detection and treatment of cancer. We have developed and are testing early prototypes of an optical biopsy system (OBS) for detection of cancer and other tissue pathologies. The OBS invokes a unique approach to optical diagnosis of tissue pathologies based on the elastic scattering properties, over a wide range of wavelengths, of the microscopic structure of the tissue. The use of elastic scattering as the key to optical tissue diagnostics in the OBS is based on the fact that many tissue pathologies, including a majority of cancer forms, manifest significant architectural changes at the cellular and sub-cellular level. Since the cellular components that cause elastic scattering have dimensions typically on the order of visible to near-IR wavelengths, the elastic (Mie) scattering properties will be strongly wavelength dependent. Thus, morphology and size changes can be expected to cause significant changes in an optical signature that is derived from the wavelength dependence of elastic scattering. The data acquisition and storage/display time with the OBS instrument is {approximately}1 second. Thus, in addition to the reduced invasiveness of this technique compared with current state-of-the-art methods (surgical biopsy and pathology analysis), the OBS offers the possibility of impressively faster diagnostic assessment. The OBS employs a small fiber-optic probe that is amenable to use with any endoscope, catheter or hypodermic, or to direct surface examination (e.g. as in skin cancer or cervical cancer). It has been tested in vitro on animal and human tissue samples, and clinical testing in vivo is currently in progress.

Optical Communication over Plastic Optical Fibers Integrated Optical Receiver Technology

CERN Document Server

Atef, Mohamed

2013-01-01

This book presents high-performance data transmission over plastic optical fibers (POF) using integrated optical receivers having good properties with multilevel modulation, i.e. a higher sensitivity and higher data rate transmission over a longer plastic optical fiber length. Integrated optical receivers and transmitters with high linearity are introduced for multilevel communication. For binary high-data rate transmission over plastic optical fibers, an innovative receiver containing an equalizer is described leading also to a high performance of a plastic optical fiber link. The cheap standard PMMA SI-POF (step-index plastic optical fiber) has the lowest bandwidth and the highest attenuation among multimode fibers. This small bandwidth limits the maximum data rate which can be transmitted through plastic optical fibers. To overcome the problem of the plastic optical fibers high transmission loss, very sensitive receivers must be used to increase the transmitted length over POF. The plastic optical fiber li...

Advances on Polymer Optical Fiber Gratings Using a KrF Pulsed Laser System Operating at 248 nm

Directory of Open Access Journals (Sweden)

Carlos A. F. Marques

2018-03-01

Full Text Available This paper presents the achievements and progress made on the polymer optical fiber (POF gratings inscription in different types of Fiber Bragg Gratings (FBGs and long period gratings (LPGs. Since the first demonstration of POFBGs in 1999, significant progress has been made where the inscription times that were higher than 1 h have been reduced to 15 ns with the application of the krypton fluoride (KrF pulsed laser operating at 248 nm and thermal treatments such as the pre-annealing of fibers. In addition, the application of dopants such as benzyl dimethyl ketal (BDK has provided a significant decrease of the fiber inscription time. Furthermore, such improvements lead to the possibility of inscribing POF gratings in 850 nm and 600 nm, instead of only the 1550 nm region. The progress on the inscription of different types of polymer optical fiber Bragg gratings (POFBGs such as chirped POFBGs and phase-shifted POFBGs are also reported in this review.

Interfacial characterization of soil-embedded optical fiber for ground deformation measurement

International Nuclear Information System (INIS)

Zhang, Cheng-Cheng; Zhu, Hong-Hu; Shi, Bin; She, Jun-Kuan

2014-01-01

Recently fiber-optic sensing technologies have been applied for performance monitoring of geotechnical structures such as slopes, foundations, and retaining walls. However, the validity of measured data from soil-embedded optical fibers is strongly influenced by the properties of the interface between the sensing fiber and the soil mass. This paper presents a study of the interfacial properties of an optical fiber embedded in soil with an emphasis on the effect of overburden pressure. Laboratory pullout tests were conducted to investigate the load-deformation characteristics of a 0.9 mm tight-buffered optical fiber embedded in soil. Based on a tri-linear interfacial shear stress-displacement relationship, an analytical model was derived to describe the progressive pullout behavior of an optical fiber from soil matrix. A comparison between the experimental and predicted results verified the effectiveness of the proposed pullout model. The test results are further interpreted and discussed. It is found that the interfacial bond between an optical fiber and soil is prominently enhanced under high overburden pressures. The apparent coefficients of friction of the optical fiber/soil interface decrease as the overburden pressure increases, due to the restrained soil dilation around the optical fiber. Furthermore, to facilitate the analysis of strain measurement, three working states of a soil-embedded sensing fiber were defined in terms of two characteristic displacements. (paper)

Micro- and nanostructured sol-gel-based materials for optical chemical sensing (2005–2015)

International Nuclear Information System (INIS)

Barczak, Mariusz; McDonagh, Colette; Wencel, Dorota

2016-01-01

This review (with 172 references) highlights the progress made in the past 10 years in silica sol-gel-based materials for use in optical chemical sensing. Following an introduction, the processes leading to the sol-gel-based and ormosil materials, their printability and methods for characterisation are discussed. Then various classes of optical sensors, with a focus on sensors for pH values, oxygen, carbon dioxide, ammonia (also in dissolved form), and heavy metal ions are described. A further section covers nanoparticle-based optical sensors mainly for use in intracellular sensing of the above species. Recent developments in this area are also emphasised and future trends discussed. (author)

Vibrational optical activity principles and applications

CERN Document Server

Nafie, Laurence A

2011-01-01

This unique book stands as the only comprehensive introduction to vibrational optical activity (VOA) and is the first single book that serves as a complete reference for this relatively new, but increasingly important area of molecular spectroscopy. Key features:A single-source reference on this topic that introduces, describes the background and foundation of this area of spectroscopy.Serves as a guide on how to use it to carry out applications with relevant problem solving.Depth and breadth of the subject is presented in a logical, complete and progressive fashion. A

Guided Optical Structures in the Military Environment

Science.gov (United States)

1986-05-01

gyroscopes using integrated optica " (ref.9A), H.C.Lefevre, J.P. Bettini, S.Vatoux and M.Papuohon showed that considerable progress had meanwhile been made...Rotating Optical Fiber Ring Intorferometer", Applied Optica , 16, p. 2605, 1977. 7. V. Vali, R. W. Shorthill, A. Goldstein, and R. S. Krogstad, "Laser...Trmometro, a fibra ottica- Italian Patent No. 04155 A/82 (1982) under extension. 7-5 10 A.M. Sohoggi, M. Dranci, G. Conforti, R. Falcioi, G.P. Preti

Implementation of Optical Characterization for Flexible Organic Electronics Applications

Science.gov (United States)

Laskarakis, A.; Logothetidis, S.

One of the most rapidly evolving sectors of the modern science and technology is the flexible organic electronic devices (FEDs) that are expected to significantly improve and revolutionize our everyday life. The FED application includes the generation of electricity by renewable sources (by organic photovoltaic cells - OPVs), power storage (thin film batteries), the visualization of information (by organic displays), the working and living environment (ambient lighting, sensors), safety, market (smart labels, radio frequency identification tags - RFID), textiles (smart fabrics with embedded display and sensor capabilities), as well as healthcare (smart sensors for vital sign monitoring), etc. Although there has been important progresses in inorganic-based Si devices, there are numerous advances in the organic (semiconducting, conducting), inorganic, and hybrid (organic-inorganic) materials that exhibit desirable properties and stability, and in the synthesis and preparation methods. The understanding of the organic material properties can lead to the fast progress of the functionality and performance of FEDs. The investigation of the optical properties of these materials can promote the understanding of the optical, electrical, structural properties of organic semiconductors and electrodes and can contribute to the optimization of the synthesis process and the tuning of their structure and morphology. In this chapter, we will describe briefly some of the advances toward the implementation of optical characterization methods, such as Spectroscopic Ellipsometry (SE) from the infrared to the visible and ultraviolet spectral region for the study of materials (flexible polymer substrates, barrier layers, transparent electrodes) to be used for application in the fabrication of FEDs.

Tissue-based water quality biosensors for detecting chemical warfare agents

Science.gov (United States)

Greenbaum, Elias [Oak Ridge, TN; Sanders, Charlene A [Knoxville, TN

2003-05-27

A water quality sensor for detecting the presence of at least one chemical or biological warfare agent includes: a cell; apparatus for introducing water into the cell and discharging water from the cell adapted for analyzing photosynthetic activity of naturally occurring, free-living, indigenous photosynthetic organisms in water; a fluorometer for measuring photosynthetic activity of naturally occurring, free-living, indigenous photosynthetic organisms drawn into the cell; and an electronics package that analyzes raw data from the fluorometer and emits a signal indicating the presence of at least one chemical or biological warfare agent in the water.

Enhancement Of Sensing Capabilities And Functionalization Of Optical Microresonators

Science.gov (United States)

Cocking, Alexander

Optical microresonators have been demonstrated to provide a large enhancement in electric field by containing an resonant mode in a very small volume. This resonant enhancement is proportional to the quality of the resonator, which for microspheres has been demonstrated to be on the order of 1010. These devices can be leveraged to greatly improve light-matter interaction and for this reason the theoretical background of optical microresonators is discussed in the second chapter. This includes the use of COMSOL Multiphysics to model the mode structure and scattering from different resonator geometries. The second chapter also contains details on the fabrication and experimental design of optical microresonators. This includes the fabrication of fiber tapers for evanescent wave coupling into the devices. Once the theoretical framework for utilizing resonators as tools for enhancement has been established in the second chapter, we progress to the discussion of the microbubble geometry and its potential for use as an on-chip sensor system. Topics covered include design, fabrication, and theoretical analysis of the mode structure in this geometry. Modal interaction with a liquid filled microbubble is demonstrated. Additionally, the use of microbubble resonators as highly accurate temperature sensors is demonstrated experimentally and theoretically. In chapter 4 we investigate the use of silica microspheres as sensing devices; specifically, using them for the purpose of sensing nano-particles and chemicals in incredibly minute quantities. In this section microresonators are demonstrated to provide enhancement to Raman scattering from nano-scale particles. This configuration retains the traditional sensing methods of resonators by observing mode shifting and splitting in the resonance spectrum, while adding in a label-free sensing ability to determine material composition on adhered micro and nanoparticles. The fifth chapter discusses the characterization of a new class

High-resolution spectroscopy of jet-cooled CH{sub 5}{sup +}: Progress

Energy Technology Data Exchange (ETDEWEB)

Savage, C.; Dong, F.; Nesbitt, D. J. [JILA, University of Colorado and National Institute of Standards and Technology, and Department of Chemistry and Biochemistry, University of Colorado, Boulder, Colorado 80309-0440 (United States)

2015-01-22

Protonated methane (CH{sub 5}{sup +}) is thought to be a highly abundant molecular ion in interstellar medium, as well as a potentially bright μwave- mm wave emitter that could serve as a tracer for methane. This paper describes progress and first successful efforts to obtain a high resolution, supersonically cooled spectrum of CH{sub 5}{sup +} in the 2900-3100 cm{sup −1} region, formed in a slit supersonic discharge at low jet temperatures and with sub-Doppler resolution. Short term precision in frequency measurement (< 5 MHz on an hour time scale) is obtained from a thermally controlled optical transfer cavity servoloop locked onto a frequency stabilized HeNe laser. Long term precision (< 20 MHz day-to-day) due to pressure, temperature and humidity dependent index of refraction effects in the optical transfer cavity is also present and discussed.

Optical properties of cosmic dust analogs: a review

Science.gov (United States)

Henning, Thomas; Mutschke, Harald

2010-04-01

Nanometer- and micrometer-sized solid particles play an important role in the evolutionary cycle of stars and interstellar matter. The optical properties of cosmic grains determine the interaction of the radiation field with the solids, thereby regulating the temperature structure and spectral appearance of dusty regions. Radiation pressure on dust grains and their collisions with the gas atoms and molecules can drive powerful winds. The analysis of observed spectral features, especially in the infrared wavelength range, provides important information on grain size, composition and structure as well as temperature and spatial distribution of the material. The relevant optical data for interstellar, circumstellar, and protoplanetary grains can be obtained by measurements on cosmic dust analogs in the laboratory or can be calculated from grain models based on optical constants. Both approaches have made progress in the last years, triggered by the need to interpret increasingly detailed high-quality astronomical observations. The statistical theoretical approach, spectroscopic experiments at variable temperature and absorption spectroscopy of aerosol particulates play an important role for the successful application of the data in dust astrophysics.

Optical macro-tweezers: trapping of highly motile micro-organisms

International Nuclear Information System (INIS)

Thalhammer, G; Steiger, R; Bernet, S; Ritsch-Marte, M

2011-01-01

Optical micromanipulation stands for contact-free handling of microscopic particles by light. Optical forces can manipulate non-absorbing objects in a large range of sizes, e.g., from biological cells down to cold atoms. Recently much progress has been made going from the micro- down to the nanoscale. Less attention has been paid to going the other way, trapping increasingly large particles. Optical tweezers typically employ a single laser beam tightly focused by a microscope objective of high numerical aperture to stably trap a particle in three dimensions (3D). As the particle size increases, stable 3D trapping in a single-beam trap requires scaling up the optical power, which eventually induces adverse biological effects. Moreover, the restricted field of view of standard optical tweezers, dictated by the use of high NA objectives, is particularly unfavorable for catching actively moving specimens. Both problems can be overcome by traps with counter-propagating beams. Our 'macro-tweezers' are especially designed to trap highly motile organisms, as they enable three-dimensional all-optical trapping and guiding in a volume of 2 × 1 × 2 mm 3 . Here we report for the first time the optical trapping of large actively swimming organisms, such as for instance Euglena protists and dinoflagellates of up to 70 µm length. Adverse bio-effects are kept low since trapping occurs outside high intensity regions, e.g., focal spots. We expect our approach to open various possibilities in the contact-free handling of 50–100 µm sized objects that could hitherto not be envisaged, for instance all-optical holding of individual micro-organisms for taxonomic identification, selective collecting or tagging

Fabrication and Operation of a Nano-Optical Conveyor Belt.

Science.gov (United States)

Ryan, Jason; Zheng, Yuxin; Hansen, Paul; Hesselink, Lambertus

2015-08-26

The technique of using focused laser beams to trap and exert forces on small particles has enabled many pivotal discoveries in the nanoscale biological and physical sciences over the past few decades. The progress made in this field invites further study of even smaller systems and at a larger scale, with tools that could be distributed more easily and made more widely available. Unfortunately, the fundamental laws of diffraction limit the minimum size of the focal spot of a laser beam, which makes particles smaller than a half-wavelength in diameter hard to trap and generally prevents an operator from discriminating between particles which are closer together than one half-wavelength. This precludes the optical manipulation of many closely-spaced nanoparticles and limits the resolution of optical-mechanical systems. Furthermore, manipulation using focused beams requires beam-forming or steering optics, which can be very bulky and expensive. To address these limitations in the system scalability of conventional optical trapping our lab has devised an alternative technique which utilizes near-field optics to move particles across a chip. Instead of focusing laser beams in the far-field, the optical near field of plasmonic resonators produces the necessary local optical intensity enhancement to overcome the restrictions of diffraction and manipulate particles at higher resolution. Closely-spaced resonators produce strong optical traps which can be addressed to mediate the hand-off of particles from one to the next in a conveyor-belt-like fashion. Here, we describe how to design and produce a conveyor belt using a gold surface patterned with plasmonic C-shaped resonators and how to operate it with polarized laser light to achieve super-resolution nanoparticle manipulation and transport. The nano-optical conveyor belt chip can be produced using lithography techniques and easily packaged and distributed.

Development of optical fiber frequency and time distribution systems

Science.gov (United States)

Lutes, G.

1982-01-01

The development of ultra stable optical fiber distribution systems for the dissemination of frequency and timing references is reported. The ultimate design goals for these systems are a frequency stability of 10 to the -17 power for tau or = 100 sec and time stability of + or - 0.1 ns for 1 year and operation over distances or = 30 km. A prototype system is reviewed and progress is discussed.

Integrated control platform for converged optical and wireless networks

DEFF Research Database (Denmark)

Yan, Ying

The next generation of broadband access networks is expected to be heterogeneous. Multiple wired and wireless systems can be integrated, in order to simultaneously provide seamless access with an appropriate Quality of Service (QoS). Wireless networks support ubiquitous connectivity yet low data...... rates, whereas optical networks can offer much higher data rates but only provide fixed connection structures. Their complementary characteristics make the integration of the two networks a promising trend for next generation networks. With combined strengths, the converged network will provide both...... the complementary characteristics of the optical networks and the wireless networks, addresses motivations for their interworking, discusses the current progress in hybrid network architectures as well as the functionalities of a control system, and identifies the achieved research contributions in the integrated...

The development of formative assessment probes for optics education

Science.gov (United States)

Dokter, Erin F. C.; Pompea, Stephen M.; Sparks, Robert T.; Walker, Constance E.

2010-08-01

Research exploring students' knowledge of optics from elementary through college has revealed that many concepts can be difficult for students to grasp. This can be the case particularly with fundamental concepts, such as the nature of light, how light interacts with matter, and how light behaves in optical systems. The use of formative assessment probes (low-stakes questions posed to students before instruction or in real-time in the classroom) can inform instructors about student background knowledge, and can also be used as they progress through learning in class. By understanding what students know prior to instruction, and how well they are learning in real-time, instruction can be designed and modified in order to encourage the development of scientifically-accurate knowledge.

Fundus autofluorescence and optical coherence tomographic findings in acute zonal occult outer retinopathy.

Science.gov (United States)

Fujiwara, Takamitsu; Imamura, Yutaka; Giovinazzo, Vincent J; Spaide, Richard F

2010-09-01

The purpose of this study was to investigate the fundus autofluorescence and optical coherence tomography findings in eyes with acute zonal occult outer retinopathy (AZOOR). A retrospective observational case series of the fundus autofluorescence and spectral domain optical coherence tomography in a series of patients with AZOOR. There were 19 eyes of 11 patients (10 women), who had a mean age of 49.1 +/- 13.9 years. Fundus autofluorescence abnormalities were seen in 17 of the 19 eyes, were more common in the peripapillary area, and were smaller in extent than the optical coherence tomography abnormalities. Nine eyes showed progression of hypoautofluorescence area during the mean follow-up of 69.7 months. The mean thickness of the photoreceptor layer at fovea was 177 microm in eyes with AZOOR, which was significantly thinner than controls (193 microm, P = 0.049). Abnormal retinal laminations were found in 12 eyes and were located over areas of loss of the photoreceptors. The subfoveal choroidal thickness was 243 microm, which is normal. Fundus autofluorescence abnormalities in AZOOR showed distinct patterns of retinal pigment epithelial involvement, which may be progressive. Thinning of photoreceptor cell layer with loss of the outer segments and abnormal inner retinal lamination in the context of a normal choroid are commonly found in AZOOR.

The Development, Commercialization, and Impact of Optical Coherence Tomography.

Science.gov (United States)

Fujimoto, James; Swanson, Eric

2016-07-01

This review was written for the special issue of IOVS to describe the history of optical coherence tomography (OCT) and its evolution from a nonscientific, historic perspective. Optical coherence tomography has become a standard of care in ophthalmology, providing real-time information on structure and function - diagnosing disease, evaluating progression, and assessing response to therapy, as well as helping to understand disease pathogenesis and create new therapies. Optical coherence tomography also has applications in multiple clinical specialties, fundamental research, and manufacturing. We review the early history of OCT describing how research and development evolves and the important role of multidisciplinary collaboration and expertise. Optical coherence tomography had its origin in femtosecond optics, but used optical communications technologies and required advanced engineering for early OCT prototypes, clinical feasibility studies, entrepreneurship, and corporate development in order to achieve clinical acceptance and clinical impact. Critical advances were made by early career researchers, clinician scientists, engineering experts, and business leaders, which enabled OCT to have a worldwide impact on health care. We introduce the concept of an "ecosystem" consisting of research, government funding, collaboration and competition, clinical studies, innovation, entrepreneurship and industry, and impact - all of which must work synergistically. The process that we recount is long and challenging, but it is our hope that it might inspire early career professionals in science, engineering, and medicine, and that the clinical and research community will find this review of interest.

The Development, Commercialization, and Impact of Optical Coherence Tomography

Science.gov (United States)

Fujimoto, James; Swanson, Eric

2016-01-01

This review was written for the special issue of IOVS to describe the history of optical coherence tomography (OCT) and its evolution from a nonscientific, historic perspective. Optical coherence tomography has become a standard of care in ophthalmology, providing real-time information on structure and function – diagnosing disease, evaluating progression, and assessing response to therapy, as well as helping to understand disease pathogenesis and create new therapies. Optical coherence tomography also has applications in multiple clinical specialties, fundamental research, and manufacturing. We review the early history of OCT describing how research and development evolves and the important role of multidisciplinary collaboration and expertise. Optical coherence tomography had its origin in femtosecond optics, but used optical communications technologies and required advanced engineering for early OCT prototypes, clinical feasibility studies, entrepreneurship, and corporate development in order to achieve clinical acceptance and clinical impact. Critical advances were made by early career researchers, clinician scientists, engineering experts, and business leaders, which enabled OCT to have a worldwide impact on health care. We introduce the concept of an “ecosystem” consisting of research, government funding, collaboration and competition, clinical studies, innovation, entrepreneurship and industry, and impact – all of which must work synergistically. The process that we recount is long and challenging, but it is our hope that it might inspire early career professionals in science, engineering, and medicine, and that the clinical and research community will find this review of interest. PMID:27409459

Application of Nanostructures in Electrochromic Materials and Devices: Recent Progress

Directory of Open Access Journals (Sweden)

Jin Min Wang

2010-11-01

Full Text Available The recent progress in application of nanostructures in electrochromic materials and devices is reviewed. ZnO nanowire array modified by viologen and WO3, crystalline WO3 nanoparticles and nanorods, mesoporous WO3 and TiO2, poly(3,4-ethylenedioxythiophene nanotubes, Prussian blue nanoinks and nanostructures in switchable mirrors are reviewed. The electrochromic properties were significantly enhanced by applying nanostructures, resulting in faster switching responses, higher stability and higher optical contrast. A perspective on the development trends in electrochromic materials and devices is also proposed.

In-vivo imaging of blood flow dynamics using color Doppler optical coherence tomography

Science.gov (United States)

Yazdanfar, Siavash; Rollins, Andrew M.; Izatt, Joseph A.

2000-04-01

Noninvasive quantitation of blood flow in the retinal micro circulation may elucidate the progression and treatment of ocular disorders including diabetic retinopathy, age-related degeneration, and glaucoma. Color Doppler optical coherence tomography was recently introduced as a technique allowing simultaneous micron-scale resolution cross-sectional imaging of tissue micro structure and blood flow in the human retina. Here, time-resolved imaging of dynamics of blood flow profiles was performed to measure cardiac pulsatility within retinal vessels. Retinal pulsatility has been shown to decrease throughout the progression of diabetic retinopathy.

Fundus autofluorescence and optical coherence tomography findings in thiamine responsive megaloblastic anemia.

Science.gov (United States)

Ach, Thomas; Kardorff, Rüdiger; Rohrschneider, Klaus

2015-01-01

To report ophthalmologic fundus autofluorescence and spectral domain optical coherence tomography findings in a patient with thiamine responsive megaloblastic anemia (TRMA). A 13-year-old girl with genetically proven TRMA was ophthalmologically (visual acuity, funduscopy, perimetry, electroretinogram) followed up over >5 years. Fundus imaging also included autofluorescence and spectral domain optical coherence tomography. During a 5-year follow-up, visual acuity and visual field decreased, despite a special TRMA diet. Funduscopy revealed bull's eye appearance, whereas fundus autofluorescence showed central and peripheral hyperfluorescence and perifoveal hypofluorescence. Spectral domain optical coherence tomography revealed affected inner segment ellipsoid band and irregularities in the retinal pigment epithelium and choroidea. Autofluorescence and spectral domain optical coherence tomography findings in a patient with TRMA show retinitis pigmentosa-like retina, retinal pigment epithelium, and choroid alterations. These findings might progress even under special TRMA diet, indispensable to life. Ophthalmologist should consider TRMA in patients with deafness and ophthalmologic disorders.

A robust single-beam optical trap for a gram-scale mechanical oscillator.

Science.gov (United States)

Altin, P A; Nguyen, T T-H; Slagmolen, B J J; Ward, R L; Shaddock, D A; McClelland, D E

2017-11-06

Precise optical control of microscopic particles has been mastered over the past three decades, with atoms, molecules and nano-particles now routinely trapped and cooled with extraordinary precision, enabling rapid progress in the study of quantum phenomena. Achieving the same level of control over macroscopic objects is expected to bring further advances in precision measurement, quantum information processing and fundamental tests of quantum mechanics. However, cavity optomechanical systems dominated by radiation pressure - so-called 'optical springs' - are inherently unstable due to the delayed dynamical response of the cavity. Here we demonstrate a fully stable, single-beam optical trap for a gram-scale mechanical oscillator. The interaction of radiation pressure with thermo-optic feedback generates damping that exceeds the mechanical loss by four orders of magnitude. The stability of the resultant spring is robust to changes in laser power and detuning, and allows purely passive self-locking of the cavity. Our results open up a new way of trapping and cooling macroscopic objects for optomechanical experiments.

International standards for optical wireless communications: state-of-the-art and future directions

Science.gov (United States)

Marciniak, Marian

2017-10-01

As the number of active OWC installations is growing fast, the standards for compatibility of co-existing neighbouring systems are being developed. The paper addresses the Laser Safety (IEC standards), ITU-T Study Group 15 standards (G.640 Co-location longitudinally compatible interfaces for free space optical systems), ITU-Radiocommunication Sector standards (P.1817-1 Propagation data required for the design of terrestrial free-space optical links), and the IEEE Work in Progress - standardization activity on Visible Light Communications. International standards of FSO communications have been reviewed and discussed. ITU, IEC, and IEEE International standards for Free-Space Optical links have been reviewed. The system reliability and availability as well as security issues will be addressed as well in the talk.

Quantum measurement in quantum optics

International Nuclear Information System (INIS)

Kimble, H.J.

1993-01-01

Recent progress in the generation and application of manifestly quantum or nonclassical states of the electromagnetic field is reviewed with emphasis on the research of the Quantum Optics Group at Caltech. In particular, the possibilities for spectroscopy with non-classical light are discussed both in terms of improved quantitative measurement capabilities and for the fundamental alteration of atomic radiative processes. Quantum correlations for spatially extended systems are investigated in a variety of experiments which utilize nondegenerate parametric down conversion. Finally, the prospects for measurement of the position of a free mass with precision beyond the standard quantum limit are briefly considered. (author). 38 refs., 1 fig

Research and development on optically pumped polarized ion sources. Technical progress report, July 1, 1985-June 30, 1986

International Nuclear Information System (INIS)

Anderson, L.W.

1986-07-01

The development of an optically pumped polarized 23 Na target is discussed. The three categories of research are: (1) electron spin relaxation of the 23 Na due to wall collisions; (2) effects of radiation trapping on the polarization that can be produced in an alkali target by optical pumping; and (3) the effects of spin exchange collisions in the polarization of a fast H 0 beam formed by charge transfer as an H + beam passes through a polarized alkali target. 90 refs., 7 figs

Roadmap on transformation optics

Science.gov (United States)

McCall, Martin; Pendry, John B.; Galdi, Vincenzo; Lai, Yun; Horsley, S. A. R.; Li, Jensen; Zhu, Jian; Mitchell-Thomas, Rhiannon C.; Quevedo-Teruel, Oscar; Tassin, Philippe; Ginis, Vincent; Martini, Enrica; Minatti, Gabriele; Maci, Stefano; Ebrahimpouri, Mahsa; Hao, Yang; Kinsler, Paul; Gratus, Jonathan; Lukens, Joseph M.; Weiner, Andrew M.; Leonhardt, Ulf; Smolyaninov, Igor I.; Smolyaninova, Vera N.; Thompson, Robert T.; Wegener, Martin; Kadic, Muamer; Cummer, Steven A.

2018-06-01

Transformation optics asks, using Maxwell’s equations, what kind of electromagnetic medium recreates some smooth deformation of space? The guiding principle is Einstein’s principle of covariance: that any physical theory must take the same form in any coordinate system. This requirement fixes very precisely the required electromagnetic medium. The impact of this insight cannot be overestimated. Many practitioners were used to thinking that only a few analytic solutions to Maxwell’s equations existed, such as the monochromatic plane wave in a homogeneous, isotropic medium. At a stroke, transformation optics increases that landscape from ‘few’ to ‘infinity’, and to each of the infinitude of analytic solutions dreamt up by the researcher, there corresponds an electromagnetic medium capable of reproducing that solution precisely. The most striking example is the electromagnetic cloak, thought to be an unreachable dream of science fiction writers, but realised in the laboratory a few months after the papers proposing the possibility were published. But the practical challenges are considerable, requiring meta-media that are at once electrically and magnetically inhomogeneous and anisotropic. How far have we come since the first demonstrations over a decade ago? And what does the future hold? If the wizardry of perfect macroscopic optical invisibility still eludes us in practice, then what compromises still enable us to create interesting, useful, devices? While three-dimensional (3D) cloaking remains a significant technical challenge, much progress has been made in two dimensions. Carpet cloaking, wherein an object is hidden under a surface that appears optically flat, relaxes the constraints of extreme electromagnetic parameters. Surface wave cloaking guides sub-wavelength surface waves, making uneven surfaces appear flat. Two dimensions is also the setting in which conformal and complex coordinate transformations are realisable, and the possibilities in

Is high myopia a risk factor for visual field progression or disk hemorrhage in primary open-angle glaucoma?

Science.gov (United States)

Nitta, Koji; Sugiyama, Kazuhisa; Wajima, Ryotaro; Tachibana, Gaku

2017-01-01

The purpose of this study was to clarify differences between highly myopic and non-myopic primary open-angle glaucoma (POAG) patients, including normal-tension glaucoma patients. A total of 269 POAG patients were divided into two groups: patients with ≥26.5 mm of axial length (highly myopic group) and patients with field (VF) loss was significantly greater in the highly myopic group (10-year survival rate, 73.7%±6.8%) than in the non-myopic group (10-year survival rate, 46.3%±5.8%; log-rank test, P =0.0142). The occurrence of disk hemorrhage (DH) in the non-myopic group (1.60±3.04) was significantly greater than that in the highly myopic group (0.93±2.13, P =0.0311). The cumulative probability of DH was significantly lower in the highly myopic group (10-year survival rate, 26.4%±5.4%) than in the non-myopic group (10-year survival rate, 47.2%±6.6%, P =0.0413). Highly myopic POAG is considered as a combination of myopic optic neuropathy and glaucomatous optic neuropathy (GON). If GON is predominant, it has frequent DH and more progressive VF loss. However, when the myopic optic neuropathy is predominant, it has less DH and less progressive VF loss.

Application of Optical Biosensors in Small-Molecule Screening Activities

Directory of Open Access Journals (Sweden)

Wolfgang Knecht

2012-03-01

Full Text Available The last two decades have seen remarkable progress and improvements in optical biosensor systems such that those are currently seen as an important and value-adding component of modern drug screening activities. In particular the introduction of microplate-based biosensor systems holds the promise to match the required throughput without compromising on data quality thus representing a sought-after complement to traditional fluidic systems. This article aims to highlight the application of the two most prominent optical biosensor technologies, namely surface plasmon resonance (SPR and optical waveguide grating (OWG, in small-molecule screening and will present, review and discuss the advantages and disadvantages of different assay formats on these platforms. A particular focus will be on the specific advantages of the inhibition in solution assay (ISA format in contrast to traditional direct binding assays (DBA. Furthermore we will discuss different application areas for both fluidic as well as plate-based biosensor systems by considering the individual strength of the platforms.

EVOLUTION THE CONCEPTS OF ROLE OF INTRAOCULAR PRESSURE IN GLAUCOMA PROGRESSION (REVIEW

Directory of Open Access Journals (Sweden)

N. I. Kurysheva

2016-01-01

Full Text Available The role of elevated intraocular pressure (IOP in the progression of glaucoma optical neuropathy has emphasized repeatedly. The question about the role of elevated IOP as the underlying cause of glaucoma arose in the early 1960s. However, epidemiological studies have questioned the role of IOP as a diagnostic criterion for glaucoma, due to the relatively rare detection the disease among those with ocular hypertension and frequent detection of glaucoma with normal IOP. Multicenter studies determining the role of antihypertensive therapy in the treatment of glaucoma, have shown the importance of reducing IOP: decricing IOP at 1 mm Hg reduced the risk of developing glaucoma on 10-19%. In addition, it was found that the rate of glaucoma progression is very variable. It depends not only on the form of glaucoma, but also on other factors such as the stage of disease and therapy. Swedish study shown normal-tension glaucoma often progressed among the patients with more aggressive treatment such as argon laser trabeculoplasty or trabeculectomies. According to the study’s data, age is the most important risk factor for the progression of normal-tension glaucoma. Such questions as fluctuations in IOP, reduction of retrobulbar blood flow, antihypertensive treatment on the progression of glaucoma are still discussed. Despite the fact that the latter UKGTS multicenter study (2014 showed a decrease in the rate of progression of glaucoma in patients treated with latanoprost, a high percentage of non-treated patients didn’t have disease’s progression. In this regard, the role of IOP as main starting factor in glaucoma pathogenesis is still open.

Applied optics and optical design

CERN Document Server

Conrady, Alexander Eugen

1957-01-01

""For the optical engineer it is an indispensable work."" - Journal, Optical Society of America""As a practical guide this book has no rival."" - Transactions, Optical Society""A noteworthy contribution,"" - Nature (London)Part I covers all ordinary ray-tracing methods, together with the complete theory of primary aberrations and as much of higher aberration as is needed for the design of telescopes, low-power microscopes and simple optical systems. Chapters: Fundamental Equations, Spherical Aberration, Physical Aspect of Optical Images, Chromatic Aberration, Design of Achromatic Object-Glass

Progress of the LANL Low Temperature/Low Frequency Air Opacity Project - Optical Theory for HET-project: an update, April 2015

Energy Technology Data Exchange (ETDEWEB)

Timmermans, Eddy Marcel Elvire [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Nisoli, Cristiano [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Mozyrsky, Dima [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Hakel, Peter [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Sherrill, Manolo [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Duffy, Leanne [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

2015-05-20

Light radiated from a hot, opaque thermal emitter originates mostly from near the surface at which the object becomes opaque (the surface of last scattering). To be specific, we define the “optical surface” as the surface at which the optical depth, as observed from a detector, takes on the value of 1. The optical depth along a line of sight depends on the wavelength dependent. Accumulating light in different spectral bands, spectral detector then records light from different surfaces, a structure that we can picture somewhat like the layers of an onion. The theoretical framework that predicts the emitted spectral signal is radioactive transfer.

Glaucoma progression detection with frequency doubling technology (FDT) compared to standard automated perimetry (SAP) in the Groningen Longitudinal Glaucoma Study.

Science.gov (United States)

Wesselink, Christiaan; Jansonius, Nomdo M

2017-09-01

To determine the usefulness of frequency doubling perimetry (FDT) for progression detection in glaucoma, compared to standard automated perimetry (SAP). Data were used from 150 eyes of 150 glaucoma patients from the Groningen Longitudinal Glaucoma Study. After baseline, SAP was performed approximately yearly; FDT every other year. First and last visit had to contain both tests. Using linear regression, progression velocities were calculated for SAP (Humphrey Field Analyzer) mean deviation (MD) and FDT MD and the number of test locations with a total deviation probability below p glaucoma progression in patients who cannot perform SAP reliably. © 2017 The Authors Ophthalmic & Physiological Optics © 2017 The College of Optometrists.

Progressive multiple cranial neuropathies presenting as a delayed complication of radiotherapy in infancy.

OpenAIRE

Pall, H. S.; Nightingale, S.; Clough, C. G.; Spooner, D.

1988-01-01

A 38 year old woman who had undergone irradiation during infancy for a left facial cutaneous arteriovenous malformation sequentially developed complete palsies of the ipsilateral VII, V, XI, IX, X, XII and VI cranial nerves. Apart from optic and olfactory nerve damage there are few reports of radiotherapy causing cranial nerve injury. We link the unusually extensive and progressive neural damage and the prolonged latency to the patient's age at time of irradiation.

Chip-integrated optical power limiter based on an all-passive micro-ring resonator

Science.gov (United States)

Yan, Siqi; Dong, Jianji; Zheng, Aoling; Zhang, Xinliang

2014-10-01

Recent progress in silicon nanophotonics has dramatically advanced the possible realization of large-scale on-chip optical interconnects integration. Adopting photons as information carriers can break the performance bottleneck of electronic integrated circuit such as serious thermal losses and poor process rates. However, in integrated photonics circuits, few reported work can impose an upper limit of optical power therefore prevent the optical device from harm caused by high power. In this study, we experimentally demonstrate a feasible integrated scheme based on a single all-passive micro-ring resonator to realize the optical power limitation which has a similar function of current limiting circuit in electronics. Besides, we analyze the performance of optical power limiter at various signal bit rates. The results show that the proposed device can limit the signal power effectively at a bit rate up to 20 Gbit/s without deteriorating the signal. Meanwhile, this ultra-compact silicon device can be completely compatible with the electronic technology (typically complementary metal-oxide semiconductor technology), which may pave the way of very large scale integrated photonic circuits for all-optical information processors and artificial intelligence systems.

Dural ectasia of the optic nerve sheath: is it always benign?

Directory of Open Access Journals (Sweden)

Berker Bakbak

2009-11-01

Full Text Available Berker Bakbak1, Hava Dönmez2, Tülay Kansu3, Hayyam Kiratli41Hacettepe University Institute of Neurological Sciences and Psychiatry, Neuro-ophthalmology Unit, Ankara, Turkey; 2Diskapi Yildirim Beyazid Education and Research Hospital Neurology Clinic, Ankara, Turkey; 3Hacettepe University Medical Faculty, Department of Neurology, Neuro-Ophthalmology Unit, Ankara, Turkey; 4Hacettepe University Medical Faculty, Department of Ophthalmology, Ocular Oncology Unit, Ankara, TurkeyAbstract: A 36-year-old woman with a 3-month history of progressive visual loss had papilledema, dilatation of the optic nerve sheaths and normal cerebrospinal fluid pressures. She was diagnosed as dural ectasia of the optic nerve sheaths and surgical decompression was performed. In this case report, severe visual loss is described as a serious complication of this rare disease and the importance of early surgical intervention is emphasized.Keywords: optic nerve, dural ectasia, meningocele

Engineering of Nanoscale Contrast Agents for Optical Coherence Tomography.

Science.gov (United States)

Gordon, Andrew Y; Jayagopal, Ashwath

2014-01-30

Optical coherence tomography has emerged as valuable imaging modalityin ophthalmology and other fields by enabling high-resolution three-dimensional imaging of tissue. In this paper, we review recent progress in the field of contrast-enhanced optical coherence tomography (OCT). We discuss exogenous and endogenous sources of OCT contrast, focusing on their use with standard OCT systems as well as emerging OCT-based imaging modalities. We include advances in the processing of OCT data that generate improved tissue contrast, including spectroscopic OCT (SOCT), as well as work utilizing secondary light sources and/or detection mechanisms to create and detect enhanced contrast, including photothermal OCT (PTOCT) and photoacoustic OCT (PAOCT). Finally, we conclude with a discussion of the translational potential of these developments as well as barriers to their clinical use.

Application of advanced optical probe instrumentation in steam generator tube bundles

International Nuclear Information System (INIS)

Bouchter, J.C.; Gouirand, J.M.; Haquet, J.F.; Ivars, J.F.

1990-01-01

The Department of Energy Transfer (DTE) of the French CEA has been developing for about 15 years optical probe techniques in order to better understand and predict nuclear components dealing with two-phase flows. More recently, in the scope of an International Program, the CEA has made an intensive use of bi-optical probes in order to very precisely investigate the distributions of void fraction and gas velocity in the secondary side of a Steam-generator mock-up operating with Freon 114 (80 degrees C, 9 x 10 5 Pa at nominal conditions). At the present time, the success of this program and the recent progress achieved in the technology of the probe, in particular to withstand higher pressures and temperatures allow us to reasonably think that this device will be soon available for industrial uses. So, this paper deals with the present state of the art of the technique within CEA and in particular it successively describes: what is required of a practical point of view when it comes to perform local measurements within tube bundles and what have been the technical choices to meet these requirements; how the bi-optical probe does operate with an emphasis on the signal processing description; how the whole device accuracy, i.e., the bi-optical probe plus its complete acquisition and signal processing chain, is determined by a calibration procedure comparing first separately then all together the different components to independent numerical and physical reference methods; typical examples of measurements of the emulsion fine structure within tube bundle subchannels as regards with void fraction, gas velocity and bubble granulometries; finally, the recent progress accomplished in terms of, higher reliability, resolution, pressure and temperature resistance

Progress in reflectance confocal microscopy for imaging oral tissues in vivo

Science.gov (United States)

Peterson, Gary; Zanoni, Daniella K.; Migliacci, Jocelyn; Cordova, Miguel; Rajadhyaksha, Milind; Patel, Snehal

2016-02-01

We report progress in development and feasibility testing of reflectance confocal microscopy (RCM) for imaging in the oral cavity of humans. We adapted a small rigid relay telescope (120mm long x 14mm diameter) and a small water immersion objective lens (12mm diameter, NA 0.7) to a commercial handheld RCM scanner (Vivascope 3000, Caliber ID, Rochester NY). This scanner is designed for imaging skin but we adapted the front end (the objective lens and the stepper motor that axially translates) for intra-oral use. This adaption required a new approach to address the loss of the automated stepper motor for acquisition of images in depth. A helical spring-like cap (with a coverslip to contact tissue) was designed for approximately 150 um of travel. Additionally other methods for focusing optics were designed and evaluated. The relay telescope optics is being tested in a clinical setting. With the capture of video and "video-mosaicing", extended areas can be imaged. The feasibility of imaging oral tissues was initially investigated in volunteers. RCM imaging in buccal mucosa in vivo shows nuclear and cellular detail in the epithelium and epithelial junction, and connective tissue and blood flow in the underlying lamina propria. Similar detail, including filiform and fungiform papillae, can be seen on the tongue in vivo. Clinical testing during head and neck surgery is now in progress and patients are being imaged for both normal tissue and cancerous margins in lip and tongue mucosa.

Nuclear theory research. Technical progress report

International Nuclear Information System (INIS)

1982-01-01

Progress is briefly described on the following studies: (1) Dirac phenomenology for deuteron elastic scattering, (2) Dirac wave functions in nuclear distorted wave calculations, (3) impulse approximation for p→p → dπ + reaction above the 3-3 resonance, (4) coherent π production, (5) nuclear potentials from Dirac bound state wavefunctions, (6) nonlocality effects in nuclear reactions, (7) unhappiness factors in DWBA description of (t,p) and (p,t) reactions, (8) absolute normalization of three-nucleon transfer reactions, (9) formulation of a finite-range CCBA computer program, (10) crossing symmetric solutions of the low equations, (11) pion scattering from quark bags, (12) study of the p 11 channel in the delta model, (13) isovector corrections in pion-nucleus scattering, (14) pionic excitation of nuclear giant resonances, and (15) isospin dependence of the second-order pion-nucleus optical potential

Optics design for J-TEXT ECE imaging with field curvature adjustment lens

Energy Technology Data Exchange (ETDEWEB)

Zhu, Y.; Zhao, Z.; Liu, W. D.; Xie, J., E-mail: jlxie@ustc.edu.cn [School of Physics, University of Science and Technology of China, Anhui 230026 (China); Hu, X.; Muscatello, C. M.; Domier, C. W.; Luhmann, N. C.; Chen, M.; Ren, X. [University of California at Davis, Davis, California 95616 (United States); Tobias, B. J. [Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543 (United States); Zhuang, G.; Yang, Z. [College of Electrical and Electronic Engineering, Huazhong University of Science and Technology, Wuhan 430074 (China)

2014-11-15

Significant progress has been made in the imaging and visualization of magnetohydrodynamic and microturbulence phenomena in magnetic fusion plasmas. Of particular importance has been microwave electron cyclotron emission imaging (ECEI) for imaging T{sub e} fluctuations. Key to the success of ECEI is a large Gaussian optics system constituting a major portion of the focusing of the microwave radiation from the plasma to the detector array. Both the spatial resolution and observation range are dependent upon the imaging optics system performance. In particular, it is critical that the field curvature on the image plane is reduced to decrease crosstalk between vertical channels. The receiver optics systems for two ECEI on the J-TEXT device have been designed to ameliorate these problems and provide good performance with additional field curvature adjustment lenses with a meniscus shape to correct the aberrations from several spherical surfaces.

Fast and accurate determination of the detergent efficiency by optical fiber sensors

Science.gov (United States)

Patitsa, Maria; Pfeiffer, Helge; Wevers, Martine

2011-06-01

An optical fiber sensor was developed to control the cleaning efficiency of surfactants. Prior to the measurements, the sensing part of the probe is covered with a uniform standardized soil layer (lipid multilayer), and a gold mirror is deposited at the end of the optical fiber. For the lipid multilayer deposition on the fiber, Langmuir-Blodgett technique was used and the progress of deposition was followed online by ultraviolet spectroscopy. The invention provides a miniaturized Surface Plasmon Resonance dip-sensor for automated on-line testing that can replace the cost and time consuming existing methods and develop a breakthrough in detergent testing in combining optical sensing, surface chemistry and automated data acquisition. The sensor is to be used to evaluate detergency of different cleaning products and also indicate how formulation, concentration, lipid nature and temperature affect the cleaning behavior of a surfactant.

Optic Neuropathy Associated with Primary Sjögren's Syndrome: A Case Series.

Science.gov (United States)

Bak, Eunoo; Yang, Hee Kyung; Hwang, Jeong-Min

2017-04-01

To determine the diverse clinical features of optic neuropathy associated with primary Sjögren's syndrome in Korean patients. Five women with acute and/or chronic optic neuropathy who were diagnosed as primary Sjögren's syndrome were retrospectively evaluated. Primary Sjögren's syndrome was diagnosed by signs and symptoms of keratoconjunctivitis sicca, positive serum anti-Ro/SSA and/or anti-La/SSB antibodies, and/or minor salivary gland biopsy. All patients underwent a complete ophthalmologic examination. Among the five patients diagnosed as optic neuropathy related to primary Sjögren's syndrome, four patients had bilateral optic neuropathy and one patient was unilateral. The clinical course was chronic in three patients and one of them showed acute exacerbation and was finally diagnosed with neuromyelitis optica spectrum disorder. The other two patients presented as acute optic neuritis and one was diagnosed with neuromyelitis optica spectrum disorder. Sicca symptoms were present in four patients, but only two patients reported these symptoms before the onset of optic neuropathy. Patients showed minimal response to systemic corticosteroids or steroid dependence, requiring plasmapheresis in the acute phase and immunosuppressive agents for maintenance therapy. Optic neuropathy associated with primary Sjögren's syndrome may show variable clinical courses, including acute optic neuritis, insidious progression of chronic optic atrophy, or in the context of neuromyelitis optica spectrum disorders. Optic neuropathy may be the initial manifestation of primary Sjögren's syndrome without apparent sicca symptoms, which makes the diagnosis often difficult. The presence of specific antibodies including anti-Ro/SSA, anti-La/SSB, and anti-aquaporin-4 antibodies are supportive for the diagnosis and treatment in atypical cases of optic neuropathy.

Contributed Review: A review of the investigation of rare-earth dopant profiles in optical fibers

Energy Technology Data Exchange (ETDEWEB)

Sidiroglou, F.; Baxter, G. [Optical Technology Research Laboratory, College of Engineering and Science, Victoria University, P.O. Box 14428, Melbourne, VIC 8001 (Australia); Roberts, A. [School of Physics, The University of Melbourne, Melbourne, VIC 3010 (Australia)

2016-04-15

Rare-earth doped optical fibers have captivated the interest of many researchers around the world across the past three decades. The growth of this research field has been stimulated primarily through their application in optical communications as fiber lasers and amplifiers, although rare-earth doped optical fiber based devices are now finding important uses in many other scientific and industrial areas (for example, medicine, sensing, the military, and material processing). Such wide commercial interest has provided a strong incentive for innovative fiber designs, alternative glass compositions, and novel fabrication processes. A prerequisite for the ongoing progress of this research field is developing the capacity to provide high resolution information about the rare-earth dopant distribution profiles within the optical fibers. This paper constitutes a comprehensive review of the imaging techniques that have been utilized in the analysis of the distribution of the rare-earth ion erbium within the core of optical fibers.

Optical constants of CH3NH3PbBr3 perovskite thin films measured by spectroscopic ellipsometry

KAUST Repository

Alias, Mohd Sharizal

2016-07-14

The lack of optical constants information for hybrid perovskite of CH3NH3PbBr3 in thin films form can delay the progress of efficient LED or laser demonstration. Here, we report on the optical constants (complex refractive index and dielectric function) of CH3NH3PbBr3 perovskite thin films using spectroscopic ellipsometry. Due to the existence of voids, the refractive index of the thin films is around 8% less than the single crystals counterpart. The energy bandgap is around 2.309 eV as obtained from photoluminescence and spectrophotometry spectra, and calculated from the SE analysis. The precise measurement of optical constants will be useful in designing optical devices using CH3NH3PbBr3 thin films.

Research progress on related genes for primary open angle glaucoma

Directory of Open Access Journals (Sweden)

Ailijiang·Aierken

2014-04-01

Full Text Available Primary open angle glaucoma(POAGis the main cause of blindness with visual field damage and optic nerve degeneration. In recent years, a lot of researches have been done, showing that genetic factors and gene mutation play an important role in POAG. There are more than 20 related POAG genes. Now we will review the related genes of POAG, especially the well known causative genes of MYOC, OPTN, WDR36, and CAV1/CAV2, in terms of their locations, structures, research progress, et al, and provide a reference for genetic research in primary open-angle glaucoma.

Progress in element analysis on a high-voltage electron microscope

International Nuclear Information System (INIS)

Tivol, W.F.; Barnard, D.; Guha, T.

1985-01-01

X-Ray microprobe (XMA) and electron energy-loss (EELS) spectrometers have been installed on the high-voltage electron microscope (HVEM). The probe size has been measured and background reduction is in progress for XMA and EELS as are improvements in electron optics for EELS and sensitivity measurements. XMA is currently useful for qualitative analysis and has been used by several investigators from our laboratory and outside laboratories. However, EELS background levels are still too high for meaningful results to be obtained. Standards suitable for biological specimens are being measured, and a library for quantitative analysis is being compiled

The Optical Bichromatic Force in Molecular Systems

Science.gov (United States)

Aldridge, Leland; Galica, Scott; Eyler, E. E.

2015-05-01

The optical bichromatic force has been demonstrated to be useful for slowing atomic beams much more rapidly than radiative forces. Through numerical simulations, we examine several aspects of applying the bichromatic force to molecular beams. One is the unavoidable existence of out-of-system radiative decay, requiring one or more repumping beams. We find that the average deceleration varies strongly with the repumping intensity, but when using optimal parameters, the force approaches the limiting value allowed by population statistics. Another consideration is the effect of fine and hyperfine structure. We examine a simplified multlevel model based on the B X transition in calcium monofluoride. To circumvent optical pumping into coherent dark states, we include two possible schemes: (1) a skewed dc magnetic field, and (2) rapid optical polarization switching. Our results indicate that the bichromatic force remains a viable option for creating large forces in molecular beams, with a reduction in the peak force by approximately an order of magnitude compared to a two-level atom, but little effect on the velocity range over which the force is effective. We also describe our progress towards experimental tests of the bichromatic force on a molecular beam of CaF. Supported by the National Science Foundation.

Optical Cladding Waveguides in Dielectric Crystals Produced by Femtosecond Laser Inscription

Directory of Open Access Journals (Sweden)

Chen Feng

2013-11-01

Full Text Available In this work, the recent progress of our research on optical cladding waveguides in dielectric crystals produced by femtosecond laser inscription has been overviewed. With different scales at cross sections, the cladding waveguides support guidance from single mode to highly multi-modes, and work for wavelength till mid-infrared regimes. Applications of the fabricated cladding structures as new integrated light sources are introduced.

Research on optical applications in nuclear industry

International Nuclear Information System (INIS)

Kim, Cheol Jung; Shin, Jang Soo; Lee, Sang Mock; Baik, Sung Hoon; Kwon, Seong Ouk; Hong, Suc Kyoung; Kim, Duk Hyeon

1988-12-01

The laser fluorometer developed in 1987 has been modified to compensate the inner filter and quenching effects. The signal processing electronic circuit was redesigned and a computer interface was introduced for data processing. It has been already used in routine chemical analysis in the chemical analysis division. Its application to uranium monitoring in conversion plant is being investigated. Also, we found that it can be used in trace analysis of samarium and europium with detection limit of 1 ppb and 0.1 ppb, respectively. The IRMPA/D process of CDF 3 and CHF 3 have been studied. The pressure effects of CDF 3 ,CHF 3 and added buffer gas were investigated. Mainly, the change in reaction rate was examined while varying the pressure of CDF 3 , CHF 3 and buffer gas. The IRMPD reaction ratio of CDF 3 and CHF 3 from below 0.1 torr up to a few torr was studied and the buffer gas pressure effect was investigated at constant pressure of CDF 3 or CHF 3 of 1 torr. Several kinds of buffer gas, Ar, N 2 , and SF 6 , were used to investigate the buffer gas pressure effect. We applied double exposure holographic interferometry, and analyzed qualitatively the distortion due to thermal heat and vibration. The research on holographic remote inspection will be achieved to apply this technique to the nuclear fuel cycle facilities. (Author)

Syringomyelia presenting with unilateral optic neuropathy: a case report.

Science.gov (United States)

Ngoo, Qi Zhe; Tai, Evelyn Li Min; Wan Hitam, Wan Hazabbah

2017-01-01

In this case report, we present two cases of syringomyelia with optic neuropathy. In Case 1, a 36-year-old Malay lady presented to our clinic with acute onset of blurring of vision in her left eye that she experienced since past 1 month. She was diagnosed with syringomyelia 12 years ago and was on conservative management. Her visual acuity was 6/6 in the right eye and counting fingers at 1 m in the left. There was a positive relative afferent pupillary defect in her left eye. Optic nerve functions of her left eye were reduced. Visual field showed a left inferior field defect. Her extraocular muscle movements were full. Magnetic resonance imaging of the brain and spine showed syringomyelia at the level of C2-C6 and T2-T9. Both of her optic nerves were normal. Her condition improved with intravenous and oral corticosteroids. In Case 2, a 44-year-old Malay lady presented to our clinic with a progressive central scotoma in her right eye that she experienced since past 1 month. She had previous history of recurrent episodes of weakness in both of her lower limbs from past 8 months. Visual acuity in her right and left eye was 6/9 and 6/6, respectively. The relative afferent pupillary defect in her right eye was positive. Optic nerve functions of her right eye were affected. Visual field showed a central scotoma in her right eye. Her extraocular muscle movements were full. Fundoscopy of her right eye showed a pale optic disc. Her left eye fundus was normal. Magnetic resonance imaging of the brain and spine showed syringomyelia at T3-T6. Both of her optic nerves were normal. A diagnosis of syringomyelia with right optic atrophy was performed. Her condition improved with intravenous and oral corticosteroids. Optic neuropathy is a rare neuro-ophthalmic manifestation in patients with syringomyelia. Prompt diagnosis and timely management are essential to avoid a poor visual outcome. Intravenous corticosteroids are beneficial in the treatment of early optic neuropathy in

Scintillating plate calorimeter optical design

International Nuclear Information System (INIS)

McNeil, R.; Fazely, A.; Gunasingha, R.; Imlay, R.; Lim, J.

1990-01-01

A major technical challenge facing the builder of a general purpose detector for the SSC is to achieve an optimum design for the calorimeter. Because of its fast response and good energy resolution, scintillating plate sampling calorimeters should be considered as a possible technology option. The work of the Scintillating Plate Calorimeter Collaboration is focused on compensating plate calorimeters. Based on experimental and simulation studies, it is expected that a sampling calorimeter with alternating layers of high-Z absorber (Pb, W, DU, etc.) and plastic scintillator can be made compensating (e/h = 1.00) by suitable choice of the ratio of absorber/scintillator thickness. Two conceptual designs have been pursued by this subsystem collaboration. One is based on lead as the absorber, with read/out of the scintillator plates via wavelength shifter fibers. The other design is based on depleted uranium as the absorber with wavelength shifter (WLS) plate readout. Progress on designs for the optical readout of a compensating scintillator plate calorimeter are presented. These designs include readout of the scintillator plates via wavelength shifter plates or fiber readout. Results from radiation damage studies of the optical components are presented

Optical aptasensors for quantitative detection of small biomolecules: a review.

Science.gov (United States)

Feng, Chunjing; Dai, Shuang; Wang, Lei

2014-09-15

Aptasensors are aptamer-based biosensors with excellent recognition capability towards a wide range of targets. Specially, there have been ever-growing interests in the development of aptasensors for the detection of small molecules. This phenomenon is contributed to two reasons. On one hand, small biomolecules play an important role in living organisms with many kinds of biological function, such as antiarrhythmic effect and vasodilator activity of adenosine. On the other hand, the concentration of small molecules can be an indicator for disease diagnosis, for example, the concentration of ATP is closely associated with cell injury and cell viability. As a potential analysis tool in the construction of aptasensors, optical analysis has attracted much more interest of researchers due to its high sensitivity, quick response and simple operation. Besides, it promises the promotion of aptasensors in performance toward a new level. Review the development of optical aptasensors for small biomolecules will give readers an overall understanding of its progress and provide some theoretical guidelines for its future development. Hence, we give a mini-review on the advance of optical aptasensors for small biomolecules. This review focuses on recent achievements in the design of various optical aptasensors for small biomolecules, containing fluorescence aptasensors, colorimetric aptasensors, chemiluminescence aptasensors and other optical aptasensors. Copyright © 2014 Elsevier B.V. All rights reserved.

High doses of biotin in chronic progressive multiple sclerosis: a pilot study.

Science.gov (United States)

Sedel, Frédéric; Papeix, Caroline; Bellanger, Agnès; Touitou, Valérie; Lebrun-Frenay, Christine; Galanaud, Damien; Gout, Olivier; Lyon-Caen, Olivier; Tourbah, Ayman

2015-03-01

No drug has been found to have any impact on progressive multiple sclerosis (MS). Biotin is a vitamin acting as a coenzyme for carboxylases involved in key steps of energy metabolism and fatty acids synthesis. Among others, biotin activates acetylCoA carboxylase, a potentially rate-limiting enzyme in myelin synthesis. The aim of this pilot study is to assess the clinical efficacy and safety of high doses of biotin in patients suffering from progressive MS. Uncontrolled, non-blinded proof of concept study 23 consecutive patients with primary and secondary progressive MS originated from three different French MS reference centers were treated with high doses of biotin (100-300mg/day) from 2 to 36 months (mean=9.2 months). Judgement criteria varied according to clinical presentations and included quantitative and qualitative measures. In four patients with prominent visual impairment related to optic nerve injury, visual acuity improved significantly. Visual evoked potentials in two patients exhibited progressive reappearance of P100 waves, with normalization of latencies in one case. Proton magnetic resonance spectroscopy (H-MRS) in one case showed a progressive normalization of the Choline/Creatine ratio. One patient with left homonymous hemianopia kept on improving from 2 to 16 months following treatment׳s onset. Sixteen patients out of 18 (89%) with prominent spinal cord involvement were considered as improved as confirmed by blinded review of videotaped clinical examination in 9 cases. In all cases improvement was delayed from 2 to 8 months following treatment׳s onset. These preliminary data suggest that high doses of biotin might have an impact on disability and progression in progressive MS. Two double-blind placebo-controlled trials are on going. Copyright © 2015 The Authors. Published by Elsevier B.V. All rights reserved.

Addition of Adapted Optics towards obtaining a quantitative detection of diabetic retinopathy

Science.gov (United States)

Yust, Brian; Obregon, Isidro; Tsin, Andrew; Sardar, Dhiraj

2009-04-01

An adaptive optics system was assembled for correcting the aberrated wavefront of light reflected from the retina. The adaptive optics setup includes a superluminous diode light source, Hartmann-Shack wavefront sensor, deformable mirror, and imaging CCD camera. Aberrations found in the reflected wavefront are caused by changes in the index of refraction along the light path as the beam travels through the cornea, lens, and vitreous humour. The Hartmann-Shack sensor allows for detection of aberrations in the wavefront, which may then be corrected with the deformable mirror. It has been shown that there is a change in the polarization of light reflected from neovascularizations in the retina due to certain diseases, such as diabetic retinopathy. The adaptive optics system was assembled towards the goal of obtaining a quantitative measure of onset and progression of this ailment, as one does not currently exist. The study was done to show that the addition of adaptive optics results in a more accurate detection of neovascularization in the retina by measuring the expected changes in polarization of the corrected wavefront of reflected light.

Progress in the specification of optical instruments for the measurement of surface form and texture

Science.gov (United States)

de Groot, Peter J.

2014-05-01

Specifications for confocal microscopes, optical interferometers and other methods of measuring areal surface topography can be confusing and misleading. The emerging ISO 25178 standards, together with the established international vocabulary of metrology, provide a foundation for improved specifications for 3D surface metrology instrumentation. The approach in this paper links instrument specifications to metrological characteristics that can influence a measurement, using consistent definitions of terms, and reference to verification procedures.

Distinguishing ischaemic optic neuropathy from optic neuritis by ganglion cell analysis.

Science.gov (United States)

Erlich-Malona, Natalie; Mendoza-Santiesteban, Carlos E; Hedges, Thomas R; Patel, Nimesh; Monaco, Caitlin; Cole, Emily

2016-12-01

To determine whether a pattern of altitudinal ganglion cell loss, as detected and measured by optical coherence tomography (OCT), can be used to distinguish non-arteritic ischaemic optic neuropathy (NAION) from optic neuritis (ON) during the acute phase, and whether the rate or severity of ganglion cell loss differs between the two diseases. We performed a retrospective, case-control study of 44 patients (50 eyes) with ON or NAION and 44 age-matched controls. Non-arteritic ischaemic optic neuropathy and ON patients had OCT at presentation and four consecutive follow-up visits. Controls had OCT at one point in time. The ganglion cell complex (GCC) was evaluated in the macula, and the retinal nerve fibre layer (RNFL) was evaluated in the peripapillary region. Ganglion cell complex thickness, RNFL thickness and GCC mean superior and inferior hemispheric difference were compared between NAION and ON patients at each time-point using unpaired t-tests and between disease and control subjects at first measurement using paired t-tests. Mean time from onset of symptoms to initial presentation was 10.7 ± 6.6 days in NAION and 11.7 ± 8.6 days in ON (p = 0.67). There was a significantly greater vertical hemispheric difference in GCC thickness in NAION patients than ON patients at all time-points (5.5-10.7 μm versus 3.1-3.6 μm, p = 0.01-0.049). Mean GCC thickness was significantly decreased at less than 2 weeks after onset in NAION compared to age-matched controls (72.1 μm versus 82.1 μm, p < 0.001), as well as in ON compared to age-matched controls (74.3 μm versus 84.5 μm, p < 0.001). Progression and severity of GCC and RNFL loss did not differ significantly between NAION and ON. A quantitative comparison of mean superior and inferior hemispheric GCC thickness with OCT may be used to distinguish NAION from ON. © 2016 Acta Ophthalmologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

UCN gravity spectrometry using neutron interference filters for fundamental investigations in neutron optics

CERN Document Server

Bondarenko, I V; Cimmino, A; Geltenbort, P; Frank, A I; Hoghoj, P; Klein, A G; Masalovich, S V; Nosov, V G

2000-01-01

A Gravity Spectrometer for ultra-cold neutrons (UCN) using neutron interference filters has been designed and tested. An energy resolution of the order of 6.5 neV was obtained which is good enough for performing a number of neutron-optical experiments proposed in an earlier paper. Experimental tests of the UCN dispersion law are currently in progress.

UCN gravity spectrometry using neutron interference filters for fundamental investigations in neutron optics

International Nuclear Information System (INIS)

Bondarenko, I.V.; Balashov, S.N.; Cimmino, A.; Geltenbort, P.; Frank, A.I.; Hoghoj, P.; Klein, A.G.; Masalovich, S.V.; Nosov, V.G.

2000-01-01

A Gravity Spectrometer for ultra-cold neutrons (UCN) using neutron interference filters has been designed and tested. An energy resolution of the order of 6.5 neV was obtained which is good enough for performing a number of neutron-optical experiments proposed in an earlier paper. Experimental tests of the UCN dispersion law are currently in progress

Comparison of automated analysis of Cirrus HD OCT spectral-domain optical coherence tomography with stereo photographs of the optic disc.

Science.gov (United States)

Sharma, Ashish; Oakley, Jonathan D; Schiffman, Joyce C; Budenz, Donald L; Anderson, Douglas R

2011-07-01

To evaluate a new automated analysis of optic disc images obtained by spectral-domain optical coherence tomography (SD OCT). Areas of the optic disc, cup, and neural rim in SD OCT images were compared with these areas from stereoscopic photographs to represent the current traditional optic nerve evaluation. The repeatability of measurements by each method was determined and compared. Evaluation of diagnostic technology. One hundred nineteen healthy eyes, 23 eyes with glaucoma, and 7 glaucoma suspect eyes. Optic disc and cup margins were traced from stereoscopic photographs by 3 individuals independently. Optic disc margins and rim widths were determined automatically in SD OCT. A subset of photographs was examined and traced a second time, and duplicate SD OCT images also were analyzed. Agreement among photograph readers, between duplicate readings, and between SD OCT and photographs were quantified by the intraclass correlation coefficient (ICC), by the root mean square, and by the standard deviation of the differences. Optic disc areas tended to be slightly larger when judged in photographs than by SD OCT, whereas cup areas were similar. Cup and optic disc areas showed good correlation (0.8) between the average photographic reading and SD OCT, but only fair correlation of rim areas (0.4). The SD OCT was highly reproducible (ICC, 0.96-0.99). Each reader also was consistent with himself on duplicate readings of 21 photographs (ICC, 0.80-0.88 for rim area and 0.95-0.98 for all other measurements), but reproducibility was not as good as SD OCT. Measurements derived from SD OCT did not differ from photographic readings more than the readings of photographs by different readers differed from each other. Designation of the cup and optic disc boundaries by an automated analysis of SD OCT was within the range of variable designations by different readers from color stereoscopic photographs, but use of different landmarks typically made the designation of the optic disc

Investigation of the spatial distribution of second-order nonlinearity in thermally poled optical fibers.

Science.gov (United States)

An, Honglin; Fleming, Simon

2005-05-02

The spatial distribution of second-order nonlinearity in thermally poled optical fibers was characterized by second-harmonic microscopy. The second-order nonlinearity was found to be confined to a thin layer close to the anode surface and progressed further into the silica as the poling time increased. Position uncertainty of the anode metal wire was observed to have an effect, as the nonlinear layers were found not always symmetrically located around the nearest points between the anode and cathode. Optical microscopy results were obtained on etched poled fiber cross-sections and compared with those from second-harmonic microscopy.

Optics

CERN Document Server

Mathieu, Jean Paul

1975-01-01

Optics, Parts 1 and 2 covers electromagnetic optics and quantum optics. The first part of the book examines the various of the important properties common to all electromagnetic radiation. This part also studies electromagnetic waves; electromagnetic optics of transparent isotropic and anisotropic media; diffraction; and two-wave and multi-wave interference. The polarization states of light, the velocity of light, and the special theory of relativity are also examined in this part. The second part is devoted to quantum optics, specifically discussing the classical molecular theory of optical p

dlx and sp6-9 Control optic cup regeneration in a prototypic eye.

Directory of Open Access Journals (Sweden)

Sylvain W Lapan

2011-08-01

Full Text Available Optic cups are a structural feature of diverse eyes, from simple pit eyes to camera eyes of vertebrates and cephalopods. We used the planarian prototypic eye as a model to study the genetic control of optic cup formation and regeneration. We identified two genes encoding transcription factors, sp6-9 and dlx, that were expressed in the eye specifically in the optic cup and not the photoreceptor neurons. RNAi of these genes prevented formation of visible optic cups during regeneration. Planarian regeneration requires an adult proliferative cell population with stem cell-like properties called the neoblasts. We found that optic cup formation occurred only after migration of progressively differentiating progenitor cells from the neoblast population. The eye regeneration defect caused by dlx and sp6-9 RNAi can be explained by a failure to generate these early optic cup progenitors. Dlx and Sp6-9 genes function as a module during the development of diverse animal appendages, including vertebrate and insect limbs. Our work reveals a novel function for this gene pair in the development of a fundamental eye component, and it utilizes these genes to demonstrate a mechanism for total organ regeneration in which extensive cell movement separates new cell specification from organ morphogenesis.

Light Optics for Optical Stochastic Cooling

Energy Technology Data Exchange (ETDEWEB)

Andorf, Matthew [NICADD, DeKalb; Lebedev, Valeri [Fermilab; Piot, Philippe [NICADD, DeKalb; Ruan, Jinhao [Fermilab

2016-06-01

In Optical Stochastic Cooling (OSC) radiation generated by a particle in a "pickup" undulator is amplified and transported to a downstream "kicker" undulator where it interacts with the same particle which radiated it. Fermilab plans to carry out both passive (no optical amplifier) and active (optical amplifier) tests of OSC at the Integrable Optics Test Accelerator (IOTA) currently in construction*. The performace of the optical system is analyzed with simulations in Synchrotron Radiation Workshop (SRW) accounting for the specific temporal and spectral properties of undulator radiation and being augmented to include dispersion of lens material.

Communication of nuclear data progress: No.9 (1993)

International Nuclear Information System (INIS)

1993-06-01

The is the ninth issue of > (CNDP), in which the nuclear data progress in China during the passed year is carried. It includes optical model parameters for both small angles and larger angles elastic scattering, n-T phase shift analyses, forbidden angular region of secondary particle emission, introduction to codes CMUP2 and CFUP1, diffusion process of nuclear fission, techniques used for charged particle evaluation at CNDC, evaluation of neutron nuclear data for 7 Li and revision on recommended data of 238 U for CENDL-2, Chinese Evaluated Nuclear Parameter Library (CENPL) (II) and computer program library at CNDC, covariance data evaluation for experimental data and several examples of least squares combination for derived data, and calculation of thermal neutron scattering law for anisotropic microcrystals etc

Recent progress in photoactive organic field-effect transistors.

Science.gov (United States)

Wakayama, Yutaka; Hayakawa, Ryoma; Seo, Hoon-Seok

2014-04-01

Recent progress in photoactive organic field-effect transistors (OFETs) is reviewed. Photoactive OFETs are divided into light-emitting (LE) and light-receiving (LR) OFETs. In the first part, LE-OFETs are reviewed from the viewpoint of the evolution of device structures. Device performances have improved in the last decade with the evolution of device structures from single-layer unipolar to multi-layer ambipolar transistors. In the second part, various kinds of LR-OFETs are featured. These are categorized according to their functionalities: phototransistors, non-volatile optical memories, and photochromism-based transistors. For both, various device configurations are introduced: thin-film based transistors for practical applications, single-crystalline transistors to investigate fundamental physics, nanowires, multi-layers, and vertical transistors based on new concepts.

Recent progress in photoactive organic field-effect transistors

International Nuclear Information System (INIS)