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conference on optical design and testing ii

作者： Yao, XL Tong, NC Xiong, CX Huazhong Inst Elect & Opt Wuhan 430074 Peoples R China

ISBN: (纸本)0819455938

optical spectrum measurements are commonly used for the routine determination of thin film optical constants. This paper presents some new methods of evaluating transmission spectrum data only, leading to thickness and values for the complex refractive index by optimizing the physical thickness, refractive index and extinction coefficient, such as step constrained optimization approach, subsection fitting, accelerating optimization model (namely, some dispersion formulae are adopted to comply with the physical constrains set), etc. The methods applies to all kinds of transmission spectra and do not rely on the existence of interference fringe patterns or transparency. Through a lot of experiments of the films Ta2O5, TiO2 under different LAD (ion-assisted deposition) conditions, the deviation between the measured and the theoretical spectra data is less than 0.53% in p-order model merit function (p = 2), which shows that these methods are reliable. Now. we have gotten the thickness and complex refractive index of DLC (Diamond-Like Carbon) films on BAK7 glass substrates by these methods successfully. Examples are presented and discussed.

关键词： optimization algorithm optical constants thin films transmission spectra ion-assisted deposition

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Measurement on a parabolic surface by quantitative shadow method in computer-controlled optical surfacing

Measurement on a parabolic surface by quantitative shadow me...

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conference on optical design and testing ii

作者： Xin, K Cheng, HB Feng, ZJ Tsing Hua Univ Dept Precis Instruments & Mechanol Beijing 100084 Peoples R China

ISBN: (纸本)0819455938

A new model developing knife-edge test to a quantified method is built in this paper. Based on knife-edge test and image-processing technology, the local surface deformations on aspheric surface can be characterized. The image-receiver CCD (756 x 504) can assure that the deformation on the little curved face can be measured and detected sensitively. For reducing the influence of the vibration of optical and image-receiving subsystems and offset of images, the least-squares procedure has been used to process images for three times. Then all of the images will be cut at the least-squares circles and moved to the same position, so every pixel on all images can be matched without any offset. In addition, the authors checked the validity of new method by measuring the characterization of parabolic surface under manufactured in our laboratory, and by processing data with simulation method on computer. The result of experiment and calculation can both approve that the least squares techniques is effective.

关键词： quantitative knife-edge model aspherical surface least-square procedure image-processing

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Adaptive phase-shifting interferometer with optical heterodyne vibration measuring and compensating system

Adaptive phase-shifting interferometer with optical heterody...

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conference on optical design and testing ii

作者： Wu, D Chen, L Xu, YX Zhu, RH Nanjing Univ Sci & Technol Sch Elect Engn & Photoelect Technol Nanjing 210094 Peoples R China

ISBN: (纸本)0819455938

In temporal phase-shifting interferometer, environmental vibrations can induce the wobbling of fringes pattern that usually results in erroneous surface measurement. In order to actively compensating for the external vibration, wave-front phase variation, in proportion to the variation of optical path difference between reference and test arm of the interferometer, should be measured firstly. So, an optical heterodyne interferometric vibration measuring system is embedded in the interferometer, the real-time wave-front phase variation due to vibration is measured by comparing phase difference of two heterodyne signals at 40MHz, one is from reference arm, another is from test arm. An acousto-optical modulator (AOM) is used as optical frequency shifter. After wave-front phase measuring, secondly, a vibration servo compensating system is built. In this system, if real-time wave-front phase is differ from preset phase, an adaptive feedback signal is formed to drive a piezoelectric transducer (PZT), and the PZT drives the standard reference mirror to shift optical path difference in order to pulling wave-front phase to the preset value, thus, vibration is compensated and fringes pattern is stabilized. Thirdly, if preset phase value is periodically changed, a series of phase-shifting interferograms cart he sampled. In the end, vibration-compensated effect of this adaptive interferometer is evaluated by an actual optical surface testing, results show this system works very well in the presence of vibrations which amplitude-frequency product is greater than 100 wave-Hertz. Frequency response of this system is restricted by PZT driven reference mirror.

关键词： phase-shifting interferometer vibration optical heterodyne vibration measuring adaptive vibration compensating optical surface testing

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ANALYSIS ON LINK FAILURES IN FREE-SPACE optical INTERCONNECTS 2

ANALYSIS ON LINK FAILURES IN FREE-SPACE OPTICAL INTERCONNECT...

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conference on Optoelectronic Interconnects ii

作者： LIOU, HY LIN, TT UNIV CALIF SAN DIEGO DEPT ELECT & COMP ENGNLA JOLLACA 92093

ISBN: (纸本)0819414484

Free space optical interconnect has provided a promising solution to the effective signal links of the increasing density and complexity in very-large-scale/large-scale integrated circuits. It is getting less affordable if such a system fails just for one tiny physical defect. Our analysis on the potential optical-electrical link failure provides guidelines for future testing and reliable system design. The study of fault models starts by exploring the underlying physical malfunctioning of the opto-electrical components, and their impacts on the assembled systems. We map the physical defects of opto-electronic devices into their corresponding logic-level representation for higher level design consideration. This mapping is chosen for its compatibility and practicability with digital electronic system designs where automated design tools can expedite the design optimization and verification process.

关键词： optical interconnects Optoelectronics Photodiodes Signal to noise ratio Systems modeling Holograms Modulators Free space optics Beam splitters Light sources

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The Need for Validation Standards in Medical Imaging

The Need for Validation Standards in Medical Imaging

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conference on design and Performance Validation of Phantoms Used in Conjunction with optical Measurements of Tissue ii

作者： Nordstrom, Robert J. NCI Bethesda MD 20892 USA

ISBN: (纸本)9780819479631

Validation of imaging technologies is becoming increasingly important as imaging begins to take a role as a biomarker. Activities such as drug development, guided intervention, patient stratification, and therapy response assessment rely on very high measurements of sensitivity and specificity at the earliest possible time point. Imaging is capable of providing those measurements, but without validation of the results, clinical acceptance will be delayed. It must be pointed out, however, that validation is different from verification, and the role of phantoms is different for these two operations. This paper discusses the need for multiple phantoms in the role of validation in order to present optical imaging devices with the extremes of tissue states expected in real-world operation.

关键词： Tissues Tissue optics Luminescence optical testing Signal attenuation Surgery Measurement devices Medical imaging optical components Clinical trials

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Spectrophotometer for measuring spectral transmittance and reflectance of large aperture optical element

Spectrophotometer for measuring spectral transmittance and r...

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conference on optical design and testing ii

作者： Liu, J Li, HF Liu, X Gu, PF Zhejiang Univ State Key Lab Modern Opt Instrumentat Hangzhou 310027 Peoples R China

ISBN: (纸本)0819455938

It is a difficult task to measure the optical uniformity of an optical coating with very large aperture. Here an automatic near-UV/VIS/NIR spectrophotometer has been developed for spectrum analysis of optical coatings on very large aperture optical elements. It can give two-dimensional scanning result of a sample with substrate surface size of 600mm*350mm and 70mm thickness. The testing beam can be s- or p-polarized, at an incident angle from 0 degrees to 70 degrees. The equipment is composed of optical system, mechanical structure, photo-translating module and computer control system. Because of the light deflection after passing through the very thick sample, an integrating sphere and a sphere moving structure was involved. The measuring beam is guided in a quartz fiber with a special interface that can improve coupling efficiency from the monochromator to fiber. The two-dimensional scanning work platform has the position accuracy about 0.05mm and a reproducibility of 0.01mm. The beam incident angle accuracy is controlled within 0.1 degrees. The measurement results show that in the near-UVNIS/NfR region, the overall photometric accuracy can get 0.1% and 0.2% for transmittance and reflectance, respectively. The wavelength scale is accurate to be within 0.4nm with a reproducibility of 0.05nm.

关键词： transmittance reflectance large aperture spectrophotometer

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optical measurement systems for industrial inspection ii: Application in industrial design

Optical measurement systems for industrial inspection II: Ap...

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optical Measurement Systems for Industrial Inspection ii: Application in Industrial design

The proceedings contains 36 papers from the the conference on optical Measurement Systems for Industrial Inspection ii:Application in Industrial design. The topics discussed include: electronic speckle pattern interferometry based on spatial fringe analysis method;long-base optical extensometer for tensile testing machines;determining 3D shapes of hybrid surfaces by laser rangefinders and speckle index in dynamic processes:application to drying of paint and two-wavelength optical tomography system for industrial applications.

关键词： optical systems

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design and test of a digital system based on a CMOS 0.35μm logarithmic pixel for pulsed laser optical detection

Design and test of a digital system based on a CMOS 0.35μm ...

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14th IEEE International conference on Electronics, Circuits and Systems

作者： Bernat, I. Padilla, M. Moreno, M. Dieguez, A. samitier, J. Univ Barcelona Dept Elect Fac Phys Barcelona Spain

ISBN: (纸本)9781424413775

This paper describes the design and testing of a digital system whose general purpose is to work as an optical detector for pulsed laser light. The system is based on a logarithmic pixel with binary output The design technology is AMS 035 mu m CMOS. The structure consists of three blocks: i) Receptor block, sensitive to the fight excitement, ii) Inverter block to amplify the signal and iii) Feedback block to memorize the output signal until next measurement. Experimental results show good response at working frequencies of 100 kHz.

关键词： pixel CMOS binary digital photodiode VLSI

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optical SENSORS FOR IN-VITRO BLOOD-GAS ANALYSIS

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SENSORS AND ACTUATORS B-CHEMICAL 1995年第1-3期29卷 169-173页

作者： LEINER, MJP AVL List GmbH Kleiststrasse 48 A-8020 Graz Austria

optical sensors for in vitro testing of blood samples have been developed. The sensors have been tested for single-shot blood gas and blood pH analysis. They work in combination with disposable plastic how-through cells, allowing calibrants and the sample to be introduced. Optic and electronic components include a tungsten-halogen lamp as the light source, photodiode detectors, interference and cut-off filters for wavelength selection and fiber optic pathways to illuminate the optodes and to return the fluorescence signals to photodiode detectors. The basic optode technology, design parameters and performance characteristics with human blood samples are presented. In the pH range 7.0-7.5 the pH optodes showed a precision of 0.014 (SD). Compared to the electrode readings, the average bias was 0.051 pH units. In the range 15-110 Torr the overall precision of the CO, optodes was 0.9 Torr (SD), and in the range 5-150 Torr the overall precision of the O-2 optodes was 0.9 Torr (SD). The results obtained are comparable to that of a state-of-the-art blood gas analyzer.

关键词： optical SENSORS BLOOD GAS ANALYSIS

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design RESULTS FOR A SET OF THIN FILM COLOR SCANNING FILTERS 2

DESIGN RESULTS FOR A SET OF THIN FILM COLOR SCANNING FILTERS

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Device-Independent Color Imaging ii conference

作者： VORA, PL TRUSSELL, HJ IWAN, L N CAROLINA STATE UNIV DEPT ELECT & COMP ENGNRALEIGHNC 27695

ISBN: (纸本)0819417610

Accurate scanning of color image, which is absolutely essential for good color reproduction, depends upon the creation of a set of filters matched to the optical system of the scanner. Previous work developed a measure of goodness for a set of color filters. The measure provides an optimization criterion which can be maximized to obtain optimal scanning filters of arbitrary spectral shapes. This paper reports on the results of fabricating and testing filters designed by this method. The results show that the filters can be fabricated accurately enough to produce increased accuracy in color measurement over existing filters.

关键词： COLOR SCANNING FILTER design COLOR REPRODUCTION

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