The hybrid-integrated optical acceleration seismic geophone is present for the first time in this paper. Double-Y branching guide, phase modulator and polarizers, which are integrated on the LiNbO₃ substrate to constitute the Michelson interference chip, hardcore of the accelerometer, are analyzed and designed respectively. The chip is fabricated successfully and the lighting test is proceeding to check the quality of the chip. The waveguides' images of chip fabricated is presented. The results of and lighting test are given too.

Position sensitive detector (PSD), which bases on the lateral photoelectric effect, is a novel position detector coming out in recent years. It can be applied to detect angle, height, distance and movement. In this paper, the development, principle, structure and its application in an active range finding system have been given.

This paper studied the image-forming characteristic of a CCD and discussed the influence of the carrier diffusion on the single pixel and whole array of CCD. Other factors have also been studied such as quantum efficiency, charge transfer, different kinds of CCD channels and the phase match between input signal and CCD pixel. Basing on above works the comprehensive model has been proposed for modulation transfer function of non-ideal CCD.

In a conventional, strip-type one-dimensional (1-D) position sensitive detector (PSD) the sensitive area and the position resistance area are combined together, the contact structure of the device is handicapped, so its accuracy and linearity is affected adversely. The sensitive area and the position resistance area in a new, comb-type 1-D PSD are separated to become the comb teeth and the comb ridge area respectively, moreover the position resistance area is made very narrow, thus the doping uniformity of that area is greatly improved. On the other hand, its position resistance can be largely increased owing to its narrower shape, if doping level is kept the same, so the restriction that is imposed on the contact structure previously can be lifted. Our measurements made on a strip-type 1-D PSD and a comb type 1-D PSD confirmed this difference, and showed that the accuracy and linearity of the comb type 1-D PSD has been increased markedly, especially the RMS nonlinearity of the comb type 1-D PSD is reduced to 0.090% from that of the strip-type 1-D PSD, 0.94%.

This paper gives the general formula of modulation transfer function for the CCD pixels with arbitrary geometric shape. Based on the formula the modulation transfer functions of CCD are compared between the square and trapezoid pixels with square sampling array. The results show that the modulation transfer function of the square pixel is better than the one of trapezoid pixel.

The principle of optical detection of ultrasound consists in measuring the phase modulation induced by the small ultrasonic surface displacement upon a probe beam impinging on the surface. An interferometer is used to transform phase-modulated light scattered from the surface into a modulated electrical signal. Since usual material surfaces are rough, such an interferometer should operate with speckled beams. Two-wave coupling via dynamic hologram recorded in a photorefractive (PR) crystal is the simplest and efficient technique for demodulation of a transient phase shift buried in a speckled wave. PR crystal acts as a self-adjusted beam combiner providing holographic adaptation of an arbitrary object-beam wave front with that of the reference beam. Besides the wave front adaptation, the crystal also automatically stabilizes an average path difference between the interfering beams thus diminishing noise caused by random optical path difference fluctuations. Here we present a novel modification of the two-wave mixing technique based on the vectorial wave coupling in PR crystals of cubic symmetry such as semiconductors and sillenites. The linear regime of phase demodulation is achieved applying an alternating external field to the crystal. It allows us to design an adaptive interferometer with sensitivity approaching to the classical homodyne detection limit.

Some characteristics of photorefractive semiconductor multiple quantum well devices are discussed from the point of view of a material for the vibration measurement system using two-wave mixing. Device structure and device fabrication is explained, and some results of the measurements on the characteristics of the device are presented and discussed. Finally, the system of vibration measurements is described and some results are discussed. The smallest detectable amplitude of the vibration is 0.4 nm and the signal is linear up to 25 nm. Cut off frequency is 34 kHz at the incident intensity of 90mW/cm².

Improvement of quality on reconstructed self-pumped phase conjugate images has been investigated. Since self-pumped phase conjugate beams generally fluctuate as a function of irradiation time, spatial and temporal changes of their fluctuations make the quality of images lower. It is necessary to study elimination of these fluctuations from phase conjugate beams for reconstruction of high quality images. However, it will be expected that this condition be decided by the intensity distribution of incident beam. In our experiments, transparent samples which consist of some thick layers were irradiated by cw argon ion laser (wavelength: 514.5nm), and recorded phase conjugate and input images were analyzed using image processing technique as a function of irradiation time. As a result, it was obvious that phase conjugate images from volume sample were stable. Finally, imaging of transparent object was studied from point of view of some thick layers and their application to optical measurements using self-pumped phase conjugate mirror were discussed.

Monte Carlo simulations are adopted to develop a numerical program to study the electron motion in the H₂/CH₄ gas mixture and the non-uniform electric field during diamond synthesis via Electric Assisted Chemical Vapor Deposition (EACVD) in order to understand this dynamical process. It is proved in this paper that there exists a reverse electric field near the substrate. With this reverse electric field, the effective radicals such as CH₃⁺ and CH⁺ can be speeded up and impact on the substrate with a higher speed, thus increase the probability of bonding. At last the electron average energy distribution and the steady space distributions of the effective radicals such as CH₃, CH₃⁺, CH⁺ and H under this field distribution are given in this paper.

In this paper, the experimental synthesis of diamond films and optical emission spectroscopy (OES) of the gaseous phase species are studied in the range of substrate temperature from Ts = 300°C to 850°C. The high quality sub-microcrystalline diamond films are successfully deposited at substrate temperature (330 ≈ 340)°C by adopting glow plasma assisted hot filament chemical vapor deposition (GPCVD). For the first time, in situ OES is applied to diagnose weak signal of GPCVD system when CH₄ and H₂ are used as the input gas, and the reactive species are identified in diamond growth processes. A primary model of diamond films growing at low temperature is presented by studying dynamic behavior for nonequilibrium plasma reactions.

The detection of heart sound is a very important method of diagnosing the heart disease. It has been a part of the woundless detection of the heart. Our team has developed a heart sound detecting system which integrates the optics with electronics. The heart sound's display on LCD is one important part of the system. In this system, the waveform of heart sound can be displayed on LCD, which makes doctors not only hear but also see during diagnosis. So it is helpful for the doctors to diagnose the heart disease more correctly. This paper mainly introduces above function's realization and its significance.

In this paper, we present an ac optical balanced homodyne detection system which enables us to detect both the amplitude and phase of the surface optical nonlinear signal. In this system, a balancing scheme and an unique lock-in detection method using fundamental interference signal as a reference has been employed. This system enables us to simultaneously measure, with extremely high sensitivity of 3 aW and high precision, both the intensity and phase of a very weak surface SHG signal. Experimental results of simultaneous measurement of the intensity and phase in surface second-harmonic waves generated from native-oxidized Si (111) surfaces is presented.

N-type strained GaInAsP/InP multiple quantum well (MQW) structures have been grown successfully using all solid source molecular beam epitaxy (MBE) and the effects of doping density in the wells on the quality of the MQW structures have been investigated. In the high-resolution x-ray diffraction curves, well-defined sharp satellite peaks up to the 15th order can be observed, indicating a very high crystalline quality of the MQW structures. With increase of Si-doping concentration in the wells, the lattice mismatch increases. The FWHM of the zero-order peak also increases and fits a Logistic function well with the doping density. The period of the MQW structures is found to decrease and the intensity of the first-order satellite peak to decays exponentially. All the observations can be explained by the changes in lattice constant, interface defects, dopant diffusion and possibly growth rate, caused by high doping in the wells of the MQW structures.

On-line spectral response measurement technology and angular-dependent X-ray photoelectron spectroscopy (XPS) technology are firstly used to research the (Cs,O) activation of Gallium arsenide (GaAs) negative electron affinity (NEA) photocathode. Dynamic spectral response can be obtained from on-line spectral response measurement system and by use of the computer program for quantitative angular-dependent XPS, atom concentration and layer thickness of activation layer can be calculated. The photocathode properties for evaluating (Cs,O) activation, such as the surface electron escape probability, diffusion length and so on are also calculated by simulation method. From our experimental results, optimum cesium deposition quantity is obtained when photocurrent arrives at peak value and then decreases to 10% of the maximum, and optimum oxygen deposition quantity is obtained when photocurrent arrives at peak value and then decreases to 90% of the maximum. And the photoemission peaks at 0.71 monolayer of Cs coverage. In our experimental system the optimum thickness of activation layer is 0.82 nm and interfacial oxidation layer is 0.2 nm for successfully activated GaAs NEA photocathode. Mechanism of interfacial barrier formation and effect of oxygen on the surface of activation layer are explained.

Detailed description of the structure, operation, fabrication, and performance of a fast-response metal-insulator-semiconductor structure mono-crystalline gallium arsenide as photo-addressing medium for infrared liquid crystal spatial light modulator (GaAs-IR-SLM) is reported. A GaAs-IR-SLM is demonstrated with a limiting resolution of 20 lp/mm over a 40 mm aperture and contrast ratios of greater than 20:1 in the 8 to approximately 12 μm wavelength.

It's unavoidable that there is a deviation (called grating period deviation in this paper) between the real QPM period of periodically poled crystal and the ideal value to cause phase mismatching. By tuning temperature, we can get phase matching again. We present the formula of the relation between temperature tuning value ΔT and grating period deviation ΔΛ of periodically poled crystal for SHG in order to get phase matching. Our numerical analyses show that ΔT of PPLN-SHG is approximately directly proportional to the ΔΛ, and when the pumping wavelength or the quasi-phase matching order increase, the slope of (formula available in paper)to approximately ΔΛ curve will go down.

Though silicon photodetectors are usually insensitive to near infrared light of the wavelength longer than 1100 nm, they become sensitive to it with high intensity, producing photocurrent in proportion to the square of the intensity. This is due to two-photon absorption (TPA) process. So far, the TPA process in silicon photodetectors has mainly been applied to measuring the waveform of optical short pulses, since it can give the intensity correlation of incident light signals. In this paper, as a new application of the TPA process in photodetectors, we propose a novel profilometry based on Michelson interferometer with optical microwave as a light source and avalanche photodiode as a two-photon absorber. In contrast to the classical heterodyne profilometer that measures the optical path length difference from the phase of the modulated optical signal, the dynamic range of the TPA method is not limited by the bandwidth of a photodetector and attached electronic devices. The TPA method can realize the dynamic range of several millimeters to several ten meters with simple setup. The principle of the TPA based profilometry is experimentally demonstrated using fiber optic Michelson interferometer.

The two-photon absorption and applications become the hot points in the recent photoelectronic material research field. The two-photon absorption materials can be applied to many fields such as up-conversion lasing, optical limiting, optical stabilization, three-dimension optical storage, three-dimension micro-machining, et al. Especially studies of optical power limiting have become more interesting to the research community because of the need for automatic protection of optical sensors against intense laser radiation. Here we report the observation of the TPA and optical power limiting property of a novel double conjugated molecule DSBDR1 in solution. The linear absorption spectral is observed using a scanning spectrophotometer. Using Nd:YAG laser pulse as exciting laser, the incident pulse energy and the transmitted pulse energy are respectively recorded by an energy meter. Then we obtain the nonlinear absorption coefficient of the novel double conjugated molecule in THF. Figures show that the molecule exhibts the large TPA cross-section and excellent optical limiting at 1064 nm. The nonlinear absorption mechanism of the novel organic compound is finally analyzed.

Waveguides can be self-written in photosensitive or photopolymerizable materials. This process results from the competition of the diffraction of the incident Gaussian beam and photopolymerization which tends to increase the refractive index where the light intensity is the highest. We have investigated the condition of quasi-solitonic and chaotic waveguide propagation inside bulk photopolymerizable materials. Light has been introduced in the medium by a single mode optical fiber. The propagated light behavior can be controlled by a careful monitoring of the input intensity. Indeed, a unique uniform channel wave guide without any broadening has been obtained by polymerization using a very low beam power of 5 μW. By increasing the input power up to 100 μW, the guide becomes chaotic and multi-channel, a process which has not been studied before in these materials. Although the transmission efficiency of two fibers connected by this type of guide is weak (10%), we can nevertheless couple two guides separated by a distance of a few millimeters. Now, this allows the study of the optical and electro-optical properties of photopolymerized guides doped by nonlinear optical chromophores and possible applications in integrated optical devices.

The In_xGa_1-xAs/InP was grown by low-pressure metalorganic chemical vapor deposition (LPMOCVD). We used Raman spectroscopy to characterize the quality of epilayers and measure the strain. Raman spectra from In_xGa_1-xAs epitaxial layers of various compositions were studied. Raman spectra were obtained at 300K, 248K, 193K, 138K, and 80K. The difference in the frequencies of their GaAs-like LO phonons was to calculate stress for the InGaAs/InP, leading to direct formula for the evaluation of the epilayer stress.

Two-photon Laser Scanning Microscopy (TPLSM) is a novel technique based on the two-photon excitation of fluorophore. In this paper, TPLSM and traditional confocal microscopy are introduced. And the influence of femtosecond near-infrared (NIR) illumination on mouse embryos is investigated for the first time. The result shows that NIR laser has much less damage to embryos than blue laser and proves that TPLSM is superior to conventional confocal microscopy in keeping sample alive. TPLSM enables us to make a continuous observation for a longer time on embryogenesis.

This paper gives a brief account of the principles and properties of the high-performance optical fiber-imaging device; on this basis, the paper puts forward a new method in producing such devices, expounds the merits of the method and, at the same time, and studies the image transmission characteristic of the optical fiber imaging-devices. Arguing that one of the vital factors affecting the high-performance optical fiber imaging-devices' imaging characteristics is the leakage of light on the fibers' interfaces, the paper introduces the effects of the quality of the coating material on the devices' imaging characteristics, and gives the result of our research.

A laser profiler in machine vision integrated sensor that scans the inspected object's surface by the rotation of the structured light is designed based on the optical triangulation. The system parameters have been optimized for a harmonious arrangement among the range resolution, the measuring accuracy and the shadow effects. The point-to-point mapping relationship among the 2D images and 3D surfaces from the different views and orientations can be developed by means of the spatial geometric correspondence. Moreover, the intensity, color and texture information from CCD images can be affixed to the entire 3D surface. As a result, near range data fusion in machine vision integrated sensor can be realized.

Along with rapid development of semiconductor, photodetector arrays (e.g. CCD) have offered the great promise of compact Optical Multichannel Analyzer (OMA) for spectrum fast measurements in a variety of applications. It deserves to pay attention to frequency response of electronic circuit in OMA, otherwise it will impair the spectrum resolving power of the analyzer. In this paper, we present a detailed frequency analysis of electronic circuit in OMA, and find that the frequency response should be met a severe condition, in which the cutoff frequency is much higher than the output frequency of photodetector arrays, to guarantee the resolution performing well in OMA.

A pressure sensor based on fiber-optical sensor (FOS) is discussed about the design parameters option in this paper. An elastic spherical diaphragm is used as a reflective target of displacement fiber sensor in this paper. The spherical diaphragm coils when force is performed upon, light intensity of receiving fiber changes depending on the deformation of it. The relationship between sensitivities of the sensor and diameters of the elastic diaphragm, diameters of fibers and the distance from the terminal of fiber to the initial diaphragm before force performed are calculated based on light distributing theory. From the consequence of calculations, we give out the optimum condition for this kind fiber sensor design. The receiving intensity of light have a goood linear relationship to the fore is presented meanwhile.

GRIN lenses, graded-index lenses, are widely used to construct micro-optic devices such as optical coupler, connector, beam splitters, optical attenuator, beam expanders, optical fiber switch and WDM, etc. Grin lens should be designed according to different uses to meet some special requirements. It is essential to realize the properties of propagation and imaging. Propagation properties and image properties of two kinds of Grin lens, respectively parabolic-index dielectric cylinder GRIN lens and tapered cylinder GRIN lens, are described in this paper. The propagation properties are studied using a ray-optics approach. We denote the passage of a ray through these GRIN lens can be described by simple 2 x 2 matrices. The parameters of this two kind GRIN lenses, such as focal length and magnifying power are given in this paper meanwhile. Comparison between cylinder GRIN lenses and tapered cylinder GRIN lenses is done in applications for coupling of light sources to fibers, beam expanding/refocusing in micro-optics devices, and splicing two fibers of different core sizes.

With a high melting point (over 2000°C), high transmission from ultraviolet to infrared wavelength approaching 4 μm, favorable mechanical strength and chemically inertness, the sapphire fiber is suitable for high temperature optical fiber sensor and near-infrared energy delivery. In this paper, the self-radiation and performance stability of sapphire fiber under high temperature was studied. Experiment results have shown that the self-radiation of sapphire fiber would influence the temperature measurement accuracy. The optical transmission loss increased with the time when the sapphire fiber was exposed to the high temperature environments. The most important factor that resulted in the performance deterioration was the direct contacting of the sapphire fiber with the protective tube and the dirtying of the evaporating substance. A suitable protective tube was applied to assure the performance stability. For further improvement of the optical properties of sapphire fiber, an alumina cladding is being developed to protect the sapphire fiber surface.

This paper describes the channeled spectropolarimetry capable of the singleshot measurement of the state of polarization (SOP) of polychromatic light. A pair of fairly-thick birefringent retarders are incorporated into the polarimeter so that all the spectrally-resolved Stokes parameters can be determined at once from only a single channeled spectrum. The principle of this method as well as its application for the ellipsometric study of thin films are presented.

This paper describes a method and system for two-dimensional measurement of birefringence dispersion with high-order and azimuthal direction. The system consists of a white light source, crossed polarizers and a detector carrying out the spectroscopic polarized light. A spectroscopic interferogram shows sinusoidaly in accordance with wave number change, and its period changes slightly because of dispersion of birefringence. The fast Fourier transform method is used to analyze the birefringence from the spectroscopic interferogram. One hundred and twenty-eight sets of images are used for birefringence analysis. Some results of 2-D birefringence dispersion distribution are shown for the demonstration of this method.

The optical characteristics of the magnetic fluid are described with the Mueller matrix measured, furthermore, the optical rotary power of the magnetic fluid is discovered. A theory to determine the rotation ratio of two retarders of the Mueller matrix imaging polarimeter is also presented. To measure the entire Mueller matrix elements, due to the sampling theorem, the rate 5 is found as the best and the unique one for this polarimeter.

A plastic disk for the next generation of an optical disk and/or a hard disk requires high quality surface. Especially its flatness is very important. Moreover surface conditions of disks are very important for covered thin film. A plastic disk inspection system is proposed by using a two-dimensional birefringence distribution using liquid crystal rederders. If there is an internal strain or a residual stress in disk, small birefringence can be observed. It is necessary for the birefringence measurement to determine the relative retardation and the azimuthal angle of the fast axis in plastic disks. In this paper, a measurement system of two-dimensional birefringence distribution is proposed. Several images captured by a CCD camera are sufficient for one birefringence distribution analysis. These experimental procedures and the results of plastic disks are discussed.

In order to measure the total mass per unit area of dew droplets deposited on a metal plate in the dew-point hygrometer, the shape of a dew droplet deposited on a copper plate was measured accurately by using an interference microscope that employed a phase-shift technique. The microscope was constructed by adding a piezoelectric transducer to an usual interference microscope. A simple method that uses a conventional speaker horn and an optical fiber cable was introduced to depress speckle noise. The shape of a dew droplet deposited on the copper plate surface with 0.1 μm in average roughness was measured with an accuracy of ±3nm. The mass of a dew droplet could be calculated numerically from the volume of its shape and was of the order of 10^-9 g. The total mass of dew droplets deposited per unit area and the deposition velocity were obtained under a gentle wind. The total mass was the order of 10^-5 g/cm² at the beginning of deposition and the deposition velocity was ranged from 2x10^-6 to 6x10^-5 g/cm².min.

Polarization interference filters (PIF) has been widely used in many fields. A successful application is color filter used for color separation and recombination in developing new LCOS projection optical sub-systems. In this paper, several techniques are discussed in order to design PIF with any arbitrary output. We present genetic algorithm (GA) optimization method to specify the desired response at first, and then a new Jones Matrix formulation was introduced to determine the orientation angles of each retarder and analyzer, which are much different from conventional "Optical Network Synthesis." Moreover, the angle property using the extended 2 x 2 Jones Matrix is also analyzed. In particular, the designed Blue/Yellow filter is provided as an illustration.

We have developed a laser-diode (LD) phase-shifting interferometer that can capture frame-rate phase-shifted interferograms on a video tape in the previous paper. The injection-current variation of LD was synchronized with the field pulse of a CCD camera to produce π/2-step phase shifts in a four-step manner. The four successive phase-shifted interferograms were used to calculate a distribution of frozen phase by a phase-extraction algorithm. In this paper we propose a LD phase-shifting interferometer with a high-speed camera that can record sequences of images from 60 to 8000 frames per second. It permits us to measure a much faster phenomena.

Two-dimensional step-profile measurement is carried out with a sinusoidal wavelength-scanning interferometer where a large scanning width of 41 nm is easily achieved using a superluminescent laser diode of a wide spectral bandwidth of 46 nm. To detect a time-varying interference signal with a short integration time of 118 μs, a shutter function of a two-dimensional CCD image sensor is utilized. A step profile with a step height of 1 μm is measured with an error less than a few nanometers. A Step profile with a step height of 20 μm is also measured with a scanning width of 23 nm.

An optical path difference (OPD) and the amplitude of sinusoidal wavelength-scanning are controlled with double feedback control system in an interferometer, so that a ruler marking every wavelength and a ruler with scales smaller than a wavelength are generated. These two rulers enable us to measure an OPD longer than a wavelength in real time. A linear CCD image sensor is used to measure one-dimensional step-profiles in real-time. Two different step profiles with a step height of 1 μm and 20 μm, respectively, are measured with the measurement error less than 8 nm. Measuring time for one measuring point is 0.04 s.

The development of the theory on self-mixing interference is reviewed. A general model is deduced. It can be used to describe self-mixing interference phenomena at high feedback levels in a laser diode with single mode or multiple modes. It is helpful to design self-mixing interference systems. At the last part of the paper, some existing questions in this area are summarized and the future research trends are listed.

The prototype of a novel sensor based on laser frequency splitting technology is presented in this paper and the results of a series of experiments are reported. A scheme of the novel pressure sensor by diode-pumped birefringent Nd:YAG dual-frequency laser is brought forward. As a result of the stress birefringence the laser's longitudinal mode is split to two with frequency difference. Both the theoretical analysis and the experiments indicate that there is a direct ratio relation between the frequency difference and the pressure imposed on the Nd:YAG crystal. Therefore when the external pressure is sensed by the Nd:YAG dual-frequency laser and the beat frequency is measured by the frequency counter, the pressure value can be obtained from the magnitude of the beat frequency. The laser can operate under single mode or complex modes with little error to the experiment results. Some research work under different pumping ways is finished and it indicates that the beat frequency has little relation with pumping ways. The experiment has a good linearity (R greater than 0.999) with satisfied precision, sensitivity (5.27 MHz/kPa) and stability, which provides a good academic and experimental foundation for further research.

In order to simplify the structure of the birefringence dual frequency laser in which a quart crystal or an artificial stress plate is settled, improve the convenience of adjustment, and improve stability of FD (frequency difference), a novel structure of dual frequency laser is constructed, in which the FD is produced by the cavity mirror coated with complex multilayer birefringent film. Different layers of the multilayer film perform different functions for the whole film system of sandwich structure. From the outermost to the innermost near the substrate, there are anti-reflectance film, birefringent film and reflectance film sequentially. Utilizing both the transverse Zeeman effect and intra-cavity birefringence effect in a He-Ne laser, frequency-difference (FD) about 7 MHz is achieved in experiments.

The tunability of the laser diode's operative wavelength is very attractive to realize active interferometer. We review here, a system that possesses this important capability, by virtue of its built-in electrical feedback loop. After describing the basic principles of its phase-control and feedback-signal generation, some selected examples of its implementation, such as displacement-, profile- and distance-measurements, as well as disturbance elimination are presented.

In this paper we present a noncollinear TeO₂ Acousto-Optic Tunable Filter (AOTF) device for a hyperspectral remote sensing system with moderate spatial and spectral resolution. The single beam configuration of the device will make the imaging optics behind it very simple and thus will make the whole system more compact. The power compensated circuit design of the RF driver of the acousto-optic filter gives relatively high and consistent diffraction efficiency over the whole tuning range in visible. The device can provide about 4° viewfield angle and 5 mm active aperture. The preliminary results have illustrated the capability of the device to be used for spectral imaging. The operation principle of AOTF will be introduced and its optical properties will be analyzed in this paper. The configuration of the AOTF device we developed for spectral imaging will be described and the measured performance of the filter will be summarized.

We propose a sinusoidal phase modulating laser diode interferometer using an additive operating type of integrating bucket method. In previous integrating bucket method, four images, which are integrated values of the interference pattern detected by a CCD image sensor, are required. According to additive and subtractive operations in a calculator, the quadrature signals can be calculated from these images. While these operations are associated with the technical computing software, such as MATLAB, in a personal computer, it is quite fast, even if the images possess large size. In a standard-alone system with a CPU, however, this kind of operation expends unbearable time. To lighten the burden of the calculator, we tried to simplify the operation. That is, on the basis of integrating bucket method, the subtraction in the signal processing is transformed to the addition by use of the phase shifting technique. All additive operations are achieved with the CCD image sensor. In this interferometer, not only the calculating quantity is reduced, but also the number of required images is reduced. The surface profile of a diamond-turned aluminum disk was measured. The repeatability in the measurements was 5.93 nm rms.

Pyroelectric uncooled focal plane array (FPA) thermal imager has the advantages of low cost, small size, high responsibility and can work under room temperature, so it has great progress in recent years. As a matched technique, the modulate chopper has become one of the key techniques in uncooled FPA thermal imaging system. Now the Archimedes spiral cord chopper technique is mostly used. When it works, the chopper pushing scans the detector's pixel array, thus makes the pixels being exposed continuously. This paper simulates the shape of this kind of chopper, analyses the exposure time of the detector's every pixel, and also analyses the whole detector pixels' exposure sequence. From the analysis we can get the results: the parameter of Archimedes spiral cord, the detector's thermal time constant, the detector's geometrical dimension, the relative position of the detector to the chopper's spiral cord are the system's important parameters, they will affect the chopper's exposure efficiency and uniformity. We should design the chopper's relevant parameter according to the practical request to achieve the chopper's appropriate structure.

The character of MRA (Multi-resolution Analysis) of wavelet transform can make the image be divided into different frequency spaces, so the image information in different frequency spaces can be processed and the features of the original image can be controlled. Wavelet transform is used widely in image compressing, edge detecting, noise filtering, image fusing etc. Based on Mallat fast algorithm in this paper, the noise of the image is filtered with threshold method after decomposing. Then the weighing operator and the comparing operator are applied for the image reconstructing, and feature-level image fusing is accomplished in practice. In contrast, it is better than the effect of other methods.

This paper presents a laser vision wheel alignment system that includes the design of the system, the working principle, the deduction of mathematical model. Coordinates unification of multiple line-structured laser sensors, which is so called global calibration, is to obtain the position and direction parameters of the multi-sensor's light plane coordinates in the world coordinates system. This paper elaborates on the method of the coordinates unification method of multi-sensors by establish a world coordinates system using two theodolites, which shows the advantage of facile movement, high accurate and most suitable to establish flexible coordinates system. The calibration accuracy is δ equals ± 0.1 mm.

Infrared thermograph technology in the research of laser-matter interaction was discussed. The formation of molten pool and heat transfer and matter transfer in laser repairing cracks of components were investigated using infrared thermal imaging system. Because the software system of HWRX-3 thermovision is not compatible with the present computer and operation system, we discussed several methods, where the compatibility has been solved and the image processing system can be transformed to windows operation system by the redesign software. The friendly user interface and very high visibility of the optimized software have been testified during laser repairing cracks of components processing. One practical method of digital process for the investigation on heat transfer and matter transfer in laser repairing cracks of components has been developed.

Star tracker is widely used for attitude determination in the field of space flight. The key part of the autonomous star sensor is the on-board database and its structure to facilitate efficient search, a hierarchical indexed guide star database is given in this paper. Bright stars that have low magnitude can be detected more easily, so we divide star to local area bright star and local area dim star, LBS is as a main role and select different combination of bright and dim star when construct star triangle. By this way, the number of triangle will be reduced. According to difference angular distance, indexes are given to hierarchical guard star database for improving the hit target rate. For its small database size and real-time is superior than the traditional database, hierarchical indexed guide star database as a reduced database is useful for new star tracker that has wide field of view, low detectability of star magnitude.

In this work we describe a family of optical devices based on heterojunction and heterodimensional structures and we investigate their static and dynamic properties. Such devices are good candidates, due to their high performance, for utilization as the sensing element for the realization of sensors in the fields of telecommunications, remote sensing, LIDAR and medical imaging. First, we present a Heterostructure Metal-Semiconductor-Metal (HMSM) photodetectors that employ a uniformly doped GaAs/AlGaAs heterojunction for the dual purpose of barrier height enhancement and creating an internal electric field that aids in the transport and collection of the photogenerated electrons. In this first family of devices, two doping levels are compared showing the direct effect of the aiding field due to modulation doping. Subsequently, we analyze a novel Resonant-Cavity-Enhanced (RCE) HMSM photodetector in which a Distributed Bragg Reflector (DBR) is employed in order to reduce the thickness of the absorption layer thus achieving good responsivity and high speed as well as wavelength selectivity. Current-voltage, current-temperature, photocurrent spectra, high-speed time response, and on-wafer frequency domain measurements point out the better performance of this last family of detectors, as they can operate in tens of Giga-Hertz range with low dark current and high responsivity. Particularly, the I-V curves show a very low dark current (around 10 picoamps at operative biases); C-V measurements highlight the low geometrical capacitance values; the photocurrent spectrum shows a clear peak at 850 nm wavelength, while time response measurements give a 3 dB bandwidth of about 30 GHz. Small signal model based on frequency domain data is also extracted in order to facilitate future photoreceiver design. Furthermore, two-dimensional numerical simulations have been carried out in order to predict the electrical properties of these detectors. Combination of very low dark current and capacitance, fast response, wavelength selectivity, and compatibility with high electron mobility transistors makes these devices especially suitable for the above-mentioned applications.

A new phase unwrapping algorithm is proposed based on temporal phase unwrappping. Given a series of wrapped phase maps generated from different fringe periods, a jump mask (or matrix) was introduced which reveal the 2π phase jump between successive levels. Using this jump mask, a series of wrapped phase can be unwrapped by summing up integers in specific column of the mask. The summation of the integers is the total multiple of 2π phase jump between wrapped and unwrapped phase. Deduction of the mask, practical experiment and discussion are carried out in detail. This method can measure discontinuity in object and accelerates the phase unwrapping procedure.

Strained p-type In_0.15Ga_0.85As/Al_0.33Ga_0.67As quantum well infrared photodetectors (QWIPs) with different Be concentrations in their wells, which detect normal infrared incidence, were investigated. The QWIPs with a Be doping density of 10¹⁸ cm^-3 in the wells show a cut-off wavelength of 7.9 μm and basically symmetric detectives of about 8 x 10⁸ cm.Hz^½/W at 600 Hz. By increasing the Be doping density in the wells to 2 x 10¹⁹ cm^-3, the cut-off wavelength is blue-shifted to about 7.25 meV and the photoresponsivity and detectivity become asymmetric. The detectivity is increased to about 1.4 x 10⁹ cm.Hz^½/W at positive biases but significantly reduced at negative biases. The blue shift in the cut-off wavelength for the QWIP devices with heavy doping concentration in the wells is mainly due to the bandgap shrinkage and the increased well width while the asymmetric behavior in the photoresponsivity and detectivity is likely due to the inhomogenity resulting from dopant diffusion at high doping.

In this paper, nanocrystalline diamond films had been synthesized by near surface glow discharge chemical vapor deposition on single-crystalline (100) silicon substrates when methane and hydrogen acted as input gases. The characters of the diamond films had been identified by scanning electron microscopy (SEM), Raman Spectrum and X-ray diffraction (XRD). The analytic results show that the high quality nanocrystalline diamond film of (111) orientation had been deposited on single-crystalline (100) silicon substrate at temperature of approximately 850°C. Simultaneously, the studies of the influence of gas pressure and CH₄ concentration in feeding gas on the diamond growth were made.

In this paper, the fundamental theory about visual range of LLL imaging system is described. Based on the revised apparent distance detecting equation and combined with the research intention and design principle of night vision goggle, the relation of parameters which have an influence on performances of system are analyzed. The visual range of the goggle under the specific circumstances is estimated, which proves the revised apparent distance detecting equation is effective and the design of the system is feasible.

We propose a new range finding technique that uses two-wavelength interferometry. The system we propose uses a single laser diode to realize a two-wavelength interferometer, which expands measurement range. The single light-source allows us to simplify the optical setup. Our device generates two independent interference signals with respect to the wavelengths generated by offset current. The external disturbances on these interference signals are eliminated by the feedback control. Although the feedback control eliminates disturbance as well as the information about the distance, we are able to detect the distance from the phase difference between those compensated interference signals.

Fiber optical Moire interferometer is a new technology in configuration or deformation measurement. It is a potential powerful microstructure mapping technique, which is important in fine processing, product monitoring, NDT, etc. Comparing with the traditional measurement methods, the optical Moire interferometer has the advantage as flexible, scale-controllable, etc. Some configurations of the fiber optic Moire interferometer are described in this paper. The ends of several polarization maintaining fibers set together under special design. They work as point optical sources to produce fringe patterns. The appearance and the trend of the fringes indicate the information of the shape or deformation of an object. Both the simplest design, only two fibers are used as the illumination source, and the complex designs, three or four fibers are put together under different distribution, are discussed in this paper. The more fibers are introduced, the more complex is the fringe pattern with more information. A series of numerical simulations have been done to compare with the result of the experiments.

Moire topography method is a well-known non-contacting 3-D measurement method. Recently, the automatic 3-D measurement by moire topography has been required since the method was frequently applied to the engineering and medical fields. 3-D measurement using projection moire topography is very attractive because of its high measuring speed and high sensitivity. In this paper, using two-wavelength methods of projection moire topography was tested to a measuring object with 2π-ambiguity problems. Experimental results prove that the proposed scheme is capable of finding absolute fringe orders, so that the 2π-ambiguity problems can be effectively overcome so as to treat large step discontinuities in measured objects.

We present a new interference microscope for quantitative measurement of transparent objects. High precision measurement is achieved by applying the phase-shifting interferometry to an ordinary transmission optical microscope. In that microscope, a bi-prism inserted between a magnifying lens and an observation plane is used as both a beam splitter and a phase shifter. The phase shift required for phase extraction using the phase-shifting technique is introduced by laterally shifting the bi-prism with a piezoelectric transducer. The diffraction caused by the vertex of the bi-prism is avoided by placing a thin wire at the center position of an intermediate image plane. Experimental results for measuring the refractive index distribution of an optical waveguide and the thickness of a biological sample are presented to demonstrate the usefulness of the this method.

A novel structure of an electronically tunable Fabry-Perot interferometer is proposed. It consists of double layers of homogeneously aligned liquid-crystal films with the buffing direction orthogonal to each other. A pure resonant wavelength, for excellent polarization-independent properties, was obtained, as both theoretical and experimental results show. It is demonstrated that the power fluctuations are less than 0.5 dB and the extinction ratios up to 7dB for our devices.

The demodulation scheme by using a discrete Hilbert transform that can change the interferometric phase by π/2 has been investigated. In-quadrature components of a fringe pattern are obtained from one captured interferogram by using a one-dimensional (1-D) discrete Hilbert transform and a 1-D discrete high-pass filtering that are based on a digital signal processing technique. The phase distribution in the range of 15π[rad] can be demodulated with the proposed method. The 1-D discrete Hilbert transform can be extended to two-dimensional calculation with a raster sampling procedure.

Spectral control of a commercial laser diode with a self-pumped phase conjugation (SPPC) feedback from a Ce:BaTiO₃ crystal was experimentally investigated. A SPPC reflectivity of as high as 65% was obtained at a 1mW incident power and a 782 nm central wavelength. The laser spectrum strongly depends on the reflectivity and length of the external SPPC cavity. The external reflectivity should be in a range of 0.1 to approximately 0.6% for our experimental setup to obtain a narrowed linewidth.

Free space laser communication is essential to provide large capacity communication with a data rate from several hundreds of Mega-bits per second to a few Giga-bits per second. In order to realize the high-data-rate, the long wavelength APDs are demanded. A low noise APD enhances the detection of weak optical signal by amplifying the electrical current generated by absorbed photons. A study of the affects of the quantum efficiency, thermal noise levels, dark current and so forth are reported in. The greater photomultiplication and the optimum optical receiver sensitivity of the APDs are also discussed practically and theoretically. APDs bias voltage compensation operating intelligently in real time through fuzzy control technique and resisting the background light interference will be presented. Using the wavelet transform, a technique of detecting optical signal and emulation results, application conclusions are demonstrated.

To implement electrostatic suspension with optoelectronic feedback control (ESOFC), real-time detection of the gap between the suspended object and the electrode is needed to determine the position of the object. In this article, we designed a laser gap sensor based on the principle of laser trigonometry, and developed a novel method to calibrate the nonlinearity of the conventional laser trigonometry by using a simple nonlinearity-correction circuit. Experiments show that this optimized sensor has an accuracy better than 7 μm when controlling the gap within the range from -2.0 mm to +2.0 mm, which meets the need of our ESOFC system quite well. Furthermore, it can also be widely applied in other displacement-detecting systems.

Microchannel plate (MCP) is a device of two-dimension array electron multiplier. The detection ability to 40 - 60 KeV X-ray for MCP was increased by coating the halide such as CsI, CsBr and KBr on input plate of MCP, that forming a reflection X-ray sensitive film in the channel with depth of 2 - 3 times of diameter below the input plate. Experiment results show that the output response of MCP with variable density structure CsI to X-ray is about 5 - 6 times higher than that with constant density structure, and of one order of magnitude stronger than that without coating the film. Comparatively, the output response of MCP with CsI sensing film is best, CsBr medium and KBr bad. The response characteristics of MCP with CsI to X-ray related to film materials, structure, component distribution and process. Several experiment curves denoted the response characteristics to X-ray at different target voltage and current. The results basically accorded with the theory about quantum detection efficiency of reflection X-ray cathode. This new MCP reflection X-ray sensitive film of variable density halide has been successfully applied in X-ray imaging detecting devices. The corresponding detection system will find widely and potential applications in the field of medical diagnosis, nondestructive evaluation and security inspection, etc.

Using high density ZnO:Al₂O₃ (AZO) target (94%) and without introducing any reaction oxygen, (001)-oriented transparent conductive AZO thin films are prepared by rf planar magnetron sputtering deposition on soda-lime glass. The structural, electrical and optical properties of the films deposited and annealed at different conditions are characterized with various techniques. The as-deposited and post-deposition annealed thin films have highly c-axis-orientated growth with hexagonal structure. Samples deposited at below 360°C are very smooth with spherical grains about tens nano-meters, the crystallization has been improved with vacuum annealing. The experimental results show that AZO thin films with optical transmittance of above 85% at wavelength of 550 nm and electrical resistivity of 10^-4 Ωcm order were achieved by deposition at substrate temperature of 360°C and subsequently annealed at 450°C for 2 h in vacuum pressure of 10^-5 Torr. With increase of the deposition temperature or post-deposition annealing in vacuum, the carrier concentration of AZO thin film increases, and the absorption edge in transmission spectra shifts toward the shorter wavelength side (blue shift).

By encapsulating a light emitting diode (LED) with a Silicon photo-negative resistance Device face to face in a hermetic package, a new type opto-isolator has been developed. Because of the features of Bistability and self-latching on the silicon photo-negative resistance devices, these non-linear opto-isolators present the response persistence function for the input signal. In this paper, the demonstration of response persistance function on PDUBAT type of silicon photo-negative resistance device has been made experimentally. The Dual Base Transistor (DUBAT) is a three terminals Voltage controlled negative resistance device, it is composed from the combination of a pnp type lateral bipolar transistor and a npn type vertical bipolar transistor. As DUBAT is radiated by light, the npn bipolar transistor is taken as a phototransistor. Thus the DUBAT will become a photo-DUBAT or PDUBAT. In PDUBAT, it is found that the photo-controlled "S" negative resistance characteristic can introduce a photo-controlled current switching effect and the persistance response functions, which keeps the response state for the input light signal until the reset signal changes the circuit from maintaining state to waiting state.

On replacing the npn bipolar transistor by a npn phototransistor in the Lambda Bipolar transistor (LBT), we can get a novel optoelectronic negative resistance detector -- photo-Lambda bipolar transistor (PLBT). In this paper, the photo-negative resistance characteristic of this device has been demonstrated by PSPICE simulation and by a fabricated experimental device. It is shown that PLBT is not only a conventional optical detector but also a basic element in the photo-induced oscillators and in the photo-controlled frequency modulator. A wide variety of application for PLBT can be expected. PLBT is composed of a npn phototransistor as main device and a n-channel enhancement-mode MOSFET as a feed back device which connected in parallel across the base and collector terminals of phototransistor. As the V_CE of photo-transistor (as same as V_GS of MOSFET) is in excess of threshold voltage V_T of MOSFET, then the MOSFET turns on and its drain current I_d will shunt the photo-base current I_phb and the collector photocurrent I_ph will decrease. The photo-negative resistance characteristic of PLBT will arise. The expressions of I_ph and negative resistance R_N have been derived from the physical model of PLBT. The simulation results of PSPICE are in agreement with measured data of the experimental PLBT device.

A New type of X-ray imaging intensifier was studied and developed. This intensifier combined with a little focal spot X-ray tube and a miniature high voltage power supply. Our product had performances of small volume, light weight, portable, high luminosity, Low X-ray radiation density and real-time imaging in daylight. The Lixiscope had also characteristics of simple structure, simple process, long lifetime, low cost and easy to application and promotion. The qualification of the imaging tube and the system: field range 50 mm, brightness 15 - 20 Cd/m², screen resolution greater than or equal to 5 lp/mm, X-ray tube current 0.05-0.10 mA, target voltage 40 - 60 KV (continuous adjustable), DC/AC available, portable 2.5 Kg. To improve the X-ray imaging intensifier, we adopted several technologies as below. The little focal spot X-ray tube (0.5 mm²) and X-ray collimator was used to increase the resolution, maximum 10 lp/mm, the fiber faceplate or light cone output window to increase brightness and field range, nd the large area and high resolution MCP to increase field range. So, the developed X-ray imaging intensifier had found the widely application.

The Zeeman He-Ne dual frequency laser produces a frequency-difference less than 3.5 MHz and birefringent dual-frequency laser produces a frequency-difference larger than 40 MHz. This paper reports a new He-Ne dual-frequency laser of 3 MHz - 40 MHz frequency-difference which has been strongly anticipated for a long time in metrology. To obtain 3 MHz - 40 MHz frequency-difference, we found two successful ways that one is to separate the ordinary light (o-light) and extraordinary light (e-light) spatially, make them travel along different optical paths and interact with the Ne atoms in their own paths, and the other is to divide Ne atoms into two kinds by applying transverse magnetic field on birefringent dual-frequency laser, one kind only interact with o-light and the other only with e-light.

This paper proposes a new digital method to compensate for the aberration of electron-objective lens in electron holography. In this method, the object wavefront in the exit pupil plane is numerically reconstructed from digitized electron hologram, and is corrected by multiplying it with the conjugate aberration function of the electron-objective lens. Then, aberration-free image can be obtained by calculating the Fresnel integral of this corrected wavefront. In comparison with traditional methods, this method is much more convenient and accurate.

CMOS APS become increasingly competitive with respect to their CCD counterparts, while adding advantages such as no blooming, simpler driving requirements and the potential of on-chip integration of sensor analogue circuitry, and digital processing functions. This paper discusses a CMOS digital camera based on EPP interface. A CMOS APS (OV7110) with VGA resolution (640 x 480) was selected as the image sensor, it can generate digital output of typically an 8 or 16 bit data bus in YUV or RGB mode, all the image controllling, e.g. frame rate, white balance, gamma control and exposure control all can be adjusted through 12C bus. The 12C bus control unit, FIFO and EPP interface, etc. are all integrated within a CPLD. The overall structure, working scheme and performance analyses of the camera were discussed in detail. Several images taken by the camera are provided and a detailed discussion of its quality, processing of image data, etc. is also given.

Small satellites are now capable of performing missions that require accurate attitude determination and control. However, low weight, size, power, and cost requirements limit the types of attitude sensors that can be used on a small craft, making attitude estimation difficult. In particular, star trackers -- often the attitude sensors of choice for spacecraft, ballistic missile etc., are not practical for small satellites, and CMOS APS is a good substitute for attitude sensors. Some of the technical advantages of CMOS APS are no blooming, low power consumption, direct digital output, small size and little support circuitry, simple to design, etc. This paper discusses the application probability of CMOS APS technology in star tracker for use in small satellites. A ground-based prototype vision system based on CMOS APS has been built to demonstrate the advantages of using CMOS APS in star tracker. Resolving capability, noise, radiation hardening and some other characteristics are discussed in detail. CMOS image sensor is sure to be a potential replacement of CCD in the field of attitude sensors.

We first proposed monolithic optoelectronic integration of Resonant Tunneling Diode (RTD) and Heterojunction Bipolar Phototransistor (HPT). Circuit simulations using simple models of RTD and HPT successfully produced the optoelectronic bistable characteristics of RTD and HPT Negative Differential Resistance (NDR) device. The basic operation mechanism of Photoelectric Monostable-Bistable Transition Logic Elements (PMOBILE's) by utilizing the functionality of two series-connected RTDs in combination with HPT is also demonstrated by simulation.

The paper discusses the fundamental constitution of the later-atmosphere communication, which uses the semiconductor lasers as light sources and the photoelectric sensors as receiving devices. It makes a deep going study to the key technique -- that the problem of receiving the large-scale signals. To resolve this problem, the system uses plane mirrors, and hollow awls as the optical receiving aerial, at the same time; it makes an extensive-area photoelectric sensor whose diameter is 50 mm with 150 multiple photodiodes. The article also discusses and analyzes the technical difficulties in detail, which come from the extensive-area photoelectric receiving. The anti-light saturation of the extenive-area photoelectric sensors, the interference of background luminance and the problem of answering time. The system is successfully used in the practical engineering fields.

A modeling and non-linear correction method for the two-dimension photoelectric position sensitive detector (PSD) is presented by means of a radial basis function (RBF) neural network. Utilizing its powerful ability in function approximation, the RBF network can perform the mapping between the PSD's readings and the light spot actual position. In order to obtain the mapping, the RBF network is trained by learning algorithm with the input/output data pairs of the PSD. The mapping is used as an inverse model of the PSD from the readings to the light spot actual position or as a forward model of it from the light spot actual position to the readings. The inverse model based on RBF network is used as a corrector. This model provides a linear response when the PSD's readings applied to the inputs of the RBF network during operation. The example shows that the measuring system with a proper RBF network correction can provide a high linearity over a wide position range. Furthermore, the forward model that expresses the characteristics of the PSD will be beneficial to provide the theoretical instruction for the analysis, design and application of the PSD.

A fiber-optic temperature probe based upon spectral photo metric detection of the change in wavelength of the optical absorption edge of a semiconductor sensor has been tested. Broadband light is coupled into optical fiber by a focusing lens, transmitted through the sensor -- a small prism of GaAs -- attached to the end of a two-fiber probe. The return light through a collimating lens is analyzed by a fast-scanning spectrometer consisting of a diffraction grating and a silicon photodiode array. The silicon photodiode array can detect the spectral line distributed in specific angle by the diffraction grating. The analog output signal is transited to digital signal which is inputted into microprocessor. The system has been applied in the measurement of the temperature in Celsius ranging from 20 to 175.

The paper introduces the overall structure and operating principle of a laser target identification system. Multi-sensor data fusion and information redundancy technology are adopted to achieve target characters synthetically judgment, which fits pratical engineering applications. In order to improving identifying distance of the targets and satisfy the miniaturization request of the system, heighten sensitivity and SNR (signal-to-noise ratio) of the sensor is a key technique. The paper discusses the technique. In addition, the paper has a detailed discussion on the overall structure of the system, target characteristic identification means and multi-sensor data fusion technology.

The double devices of position-sensitive detector (PSD) technique is studied in this paper. This apparatus which is used as a plumb line coordinator can be used to observe dam deformation, and so on. Two narrow gaps in this apparatus are proposed to replace the lens which are apt to become mildewed in moist circumstance. Two PSDs are set up in orthogonal directions. And the two gap-PSD systems can be employed for measuring a plumb line's two-dimensional displacement. Experiments are aided by a computer which is used to handle the data collected by PSD. Using this system to track the position of a plumb line, the accuracy is better than 0.05 mm.

The model of laser communication system using in vehicle mobile target was built. Optimal design and calculation was analyzed for system performance, such as laser transmission, photoelectric reception and speech information processing and image stabilization. Algorithm of MELP (Mixed Excitation Line Predication) compressed speech scrambling was received in processing voice message, which reached 2.4 kbps digital speech code stream, and realized digitization of laser communication. It was also analyzed carefully about the principle theory of MELP algorithm encoding and decoding as well as algorithm realization used in DSP. Image stabilization and tracking were realized by process signal errors which acquired at quadrant error sensors.

CMOS process is mainstream technique in VLSI, possesses high integration. SE402 is multifunction microcontroller, which integrates image data I/O ports, clock control, exposure control and digital signal processing into one chip. SE402 reduces the number of chips and PCB's room. The paper studies emphatically on USB video image controller used in CMOS image sensor and give the application on digital still camera.

A special man-made 2-D bar code ruler is applied to the CCD image measurement of 2-D micro-displacement of close quarters object in this paper. The bar code ruler is a set of concentric annulus in which the widths of them are based on cosine rule. In measuring process, the ruler is attached to the object, moving with it, and the relatively fixed CCD collects the image data of the bar code before and after the movement. From analysis of phase shifts of those image data, we can get the measuring results. Besides that the measurement precision is affected by quantization, the size of pixels and interspaces between pixels, there are other factors which can cause distorted image data and in turn result in errors in results. By comparison of the decussating form and the concentric annular form of the bar code, we can see that though not all the image data of the whole annulus make contribution to the calculation of phase shifts, the latter form plays a great role in practical application for it ensures the precondition which makes it possible to get correct measurement and detect the distorted image data.

Self-mixing interference (SMI) effects have been widely used in measuring the distance and displacement and velocity. Conventional methods are fringe counting and phase analysis. The former method has a precision of λ/10 in a multi-mode LD pumped solid-state laser (LDPSSL), while the latter has a precision of nearly λ/50 concerning the multiple reflections. Theoretical analysis and simulation calculations are presented.

In infrared imager system of using infrared focal sensor, for the responsivity heterogeneity among focal plan image elements and sensors and amplifiers can not be made in model of one to one, this kind of system asks for compensation of the heterogeneity of sensor response. Measuring the heterogeneity of focal plane image elements response accurately is the key to assure the quality of compensation. The article introduces a new method of measuring the heterogeneity of focal plane image elements response. It avoids the affect of black body radiate plane's spatial heterogeneity on the measuring result and gets higher measuring precision.

The design scheme and structure of a high accuracy temperature-controlling thermal radiation source for thermographic inspection are presented, the performance parameters of temperature-controlling thermal radiation source is given.

A new kind of Erbium-doped heavy fluoride glass Er:ZBLALiP was elaborated, and microspheres were fabricated with this fluoride glass. Thermal properties and spectroscopic properties of Er:ZBLALiP excited at 805 nm were investigated. Based on this thermalization effects between upper levels of green fluorescence in Er:ZBLALiP, we proposed an optical temperature sensing using micrometer-sized spherical cavity. The sphere temperature is scaled by the ratio of green emission intensities at 522 and 547 nm. A wide dynamic temperature ranging from 100 K to 850 K can be utilized by this type of point temperature sensor.

By using mixed-mode simulator in ATLAS, a commercial simulator produced by Silvaco International, a CMOS-process-compatible opto-electronic integrated circuit (OEIC) receiver is designed. The OEIC receiver can be used in optical communications or optical interconnections. The optical wavelength response, optical frequency response and optical pulse response of the OEIC receiver are simulated in 0.35 μm and 0.6 μm CMOS process. The sensitivity and the bandwidth of the OEIC receiver are optimized in giving detector area. Available receiver bandwidth is optimized under the given input optical power and detector area. The feedback voltage in trans-impedance amplifier is designed both for bandwidth and for sensitivity. The OEIC receiver was fabricated with a 0.6 μm CMOS process through MPW (multi-projector wafer) in China.

The performance parameter of 2D Position Sensitive Detector (PSD) are analyzed and calculated theoretically. The non-linearity and distortion grid map of the theoretical calculation using this structure position formula are in good agreement with the experimental result. The experimental results show that with the signal processor, the position non-linearity (rms) is less than 0.15% in the 60% range of a 13 mm x 13 mm active area, the position error is less than ±20 μm. It has demonstrated that 2D PSD was obtained the best position non-linearity results of 13 mm x 13 mm.

Position Sensitive Detector (PSD) is a device utilizing the lateral photoelectric that produced by the non-uniform illumination of a rectifying semiconductor junction. The linear requirement, spectral responds, position detection error of 1D PSD were presented in this paper. All these studied works are the theoretical basis for designing and fabrication PSD with excellent performance. The experimental results show that the rms non-linearity and the typcial position error are 0.1% of full length (8 mm) and ±5μm.

According to the requirement of high power laser beams and beam focus diagnostic instrument for measuring laser transverse intensity distribution, a new method of CO₂ laser rapid detecting by pyroelectric detector is given. The rapid response of photoelectric transformation with large enough gain is obtained. The response time is shorter than an order of magnitude comparing with common method. The detector can operate in normal room temperature, and need no cooling set. The photoelectric transformation system satisfies the measurement requirement of high power laser density cross-section distribution. The method can be employed for application concerning with rapid response of pyroelectric detector.

A fast phase measuring profilometry (PMP) using structured illumination with a digital micro-mirror device (DMD) has been extensively studied because of its advantage of the programmable projection. In the traditionary PMP, the phase-shift device is mechanical based and is controlled by step-motor which may cause phase errors more or less and several frames of deformed fringe patterns should be capture, which may take a longer time. In the system a DMD is used for projecting only one complex color distribution on the surface of the measured object. In the distribution three interlaced RGB based tricolor sinusoidal chroma two-dimensional fringe patterns are synchronously coded by which the phase difference of the patterns are 120 degree one another. A 24-bit color CCD digital camera is used as the detector to capture only one frame of the deformed complex color distributions. By using image separating techniques the three deformed interlaced tricolor sinusoidal chroma two-dimensional fringe patterns can be decoded individually. Using the 3-step phase shift algorithm the three-dimensional topography can be reconstructed from these decoded deformed fringe patterns. To improve the phase measurement accuracy the RGB tricolor based chroma transfer function (CTF) of the measuring system is introduced. The experiments show that by a reverse correction method with the CTF the phase measurement accuracy has been improved obviously.

A detailed comparison between conventional image intensifiers and electron bombarded CCD (EBCCD) is conducted. These sensors' advantages and drawbacks are analyzed. EBCCD with transferred electron (TE) photocathode and its application in Laser Illuminated Viewing and Ranging (LIVAR) system are shown in details. The TE Photocathode (TEP) developed by Intevac in 1996 has a demonstrated quantum efficiency of 20% or higher over the spectral range between 0.95 and 1.7 μm. The TEP is coupled directly with a CCD chip in an electron bombarded CCD (EBCCD) configuration. The overall noise figure of the EBCCD camera is close to one, approximately half that of a standard Generation-III image intensifier. The EBCCD eliminates the micro-channel plate (MCP), phosphor screen, and fiber optics, and as a result both improved image quality and increased sensitivity can be obtained in a smaller sized camera. Because of the reduction in the number of image conversions and the significantly greater signal-to-noise performance, an EBCCD has higher contrast and resolution than an ICCD. These characteristics make the EBCCD a good candidate for military, helmet-mounted night-vision systems as well as for covert surveillance applications.