By using the Hartmann-Shack wavefront sensor of the 61 element adaptive optical system, power spectra density (PSD) of the atmosphere disturbed wavefront, both overall tilt removed and leave in, was measured and analyzed. A method of calculating the Greenwood frequency and the needed control bandwidth of the deformable mirror of an adaptive optical system from measured PSDs was discussed.

The development of tomographic imaging technique-optical coherence tomography (OCT) is based on the low interference reflectometry. The study on imaging enhancement with some basic technologies of image reconstruction is presented. The point-spread function, which was necessary for the deconvolution, was obtained in our experimental measurement. The depth resolution of reconstructed image was enhanced by one order of magnitude and the image became sharper and cleaner.

An iterative algorithm of multi-aperture transformation and connection technique in cylindrical coordinates is derived. The convergence and the accuracy of this algorithm have been examined by means of computer simulation. It is demonstrated that this algorithm will play an important role in 360° profilometry.

A criterion to determine the maximum resolving power of a resolving power test chart by using Fourier power spectrum is proposed. It is an objective evaluation method, in which the Fourier frequency spectra of the resolving power test chart are analyzed and processed according to the optical information processing principle. The mathematical model of Fourier power spectrum is derived. The relations between the resolving power of the test chart and the critical maximum are defined through theoretical calculation and analysis of Fourier power spectrum of the test chart.

Acoustic emission (AE) technique has been applied to metallic and concrete structures as a nondestructive testing (NDT) method for detection of internal cracks. Current techniques employ PZT transducers for acquisition of AE signal. The work presented here describes development and testing of an AE sensor based on the optical fiber technology. It can monitor the crack signal in the concrete structure, for example, bridge, highway, tunnel and building etc., using the embedded optical fiber sensor.

A new approach for measuring the surface profile is presented. It measures the surface profile not by measuring phase but by measuring the parameters, which is relative to the white-light phase-shifting interferometric intensity and monotonic function of the depth of the tested surface in the given measurement range. Advantage of the approach is that the depth measurement range is expanded very much, it can be used to measure the profile of the deep or discontinuous surface.

The photon counting image system is able to detect the ultra-weak bioluminescence of the macro image of organisms. To study the luminescence of cell or molecules, the microscopic photon counting image system is necessary. The difference of two systems is that the microscopic photon counting image system is a noise limited system. The light source of radioisotope 14C is used for examination the state to ensure the limit detect of microscopic photon counting image system. The fundamental capability of the system is to measure the distribution and function of extremely small amounts of biomolecules, to realise real time visualisation of oxyradical burst activities, continuous observation of the calcium ion wave moving, and monitoring of gene expression etc. It will be an important development of transform from photon to molecule and from image of histology to image of function, promising for applications in the field of biology and medical science.

The Principle of a novel polarization interference imaging spectrometer (PIIS) is described and the shearing and imaging principle of the PIIS is analyzed. Influence of polarized direction of polarizer and analyzer on modulation depth of spatially distributed interferogram is analyzed and calculated. The dependence of modulation depth on deviation is calculated with polarized direction deviating from the ideal direction. Spatial curved surface of variation of the modulation depth with deviation and spatial orientation of polarizer′s polarization direction in the case of the maximum modulation depth (V=1) or minimum modulation depth (V=0) are given and discussed.

A newly-developed multi-doped red emission single crystal phosphor (Eu3+:Sm3+:Cr3+:YAG) prepared by liquid phase epitaxy on a 54 mm diameter monocrystalline YAG substrate is reported. The chromaticity coordinates of the emission of this material are x=0.6137, y=0.3738, and it is equivalent to a red light of a wavelength of 599 nm with good color saturation. This novel monocrystalline phosphor can withstand incident electron beam with high energy (up to 105 W/m2) without lighting quenching or “burning in”. All these properties show that it′s an ideal red emission material.

Sb-doped PbWO4 crystals have been grown by means of modified Bridgman method. Based on the results of measuring their transmission spectra, excitation-emission spectra, X-ray excited luminescence spectra, light output and irradiation damage, the effects on improving the optical and scintillation performances of PbWO4 crystal have been discussed.

The optical parameters of GeTe semiconductor films prepared and annealed at different temperatures have been measured by using a new method. A compared study by means of using a spectrum ellipsometer is presented. The optical parameters of the samples are obtained through the processes of data simulation and correction of the old calculation model. In the meantime, the data calculations of the same samples measured by a spectrum ellipsometer are presented, and the complex refractive index curves of them in the spectrum range from 250 nm to 830 nm are obtained.

The statistical properties of second harmonic generation in a single mode laser is investigated. The expressions of the probability distribution function, second and third factorial moments of the photon counting m in second harmonic light are derived from a full saturation laser theory. Compared to the experimental measurements, good agreement is obtained near threshold region. It is shown that the fluctuations of the fundamental and second harmonic light in the laser field decrease as the cavity decay constant increases. However, the multiplicative noise can enhance the fluctuation of fundamental light, meanwhile it can reduce the fluctuation of the second harmonic light.

When a long external cavity semiconductor laser (ECLD) is tuned to oscillate at different frequencies, the optical bistabilities of ECLDs are studied by using expressions of the threshold carrier density and carrier dependent refractive index. The criterion for observing optical bistability on the P-ν curve of an ECLD has been established and the expression for the hysteresis loop width has been deduced.

The relation between the diffraction efficiency of volume grating written by two wave mixing in Ce:KNSBN photorefractive crystal and writing beam parameters such as polarization and beam ratio was studied. The phenomenon that the diffraction efficiency strongly depends on writing beams polarization was analyzed, and the modified coupled-wave theory was used to fit the experimental data. The results give a powerful support to the application of Ce:KNSBN crystal in holographic recording and optical information process.

A scheme of detecting multiplexed signal of fiber Bragg grating (FBG) sensor using cantilever beam tunable filtering technique is presented. The principle of the sensor is analyzed and the wavelength divided multiplex sensing property is demonstrated experimentally. The results of sensing measurement are accord with the resules measured with optical spectrum analyzer. The wavelength resolution of the sensor is mainly determined by the minimal detectable optical power of the system. The wavelength resolution of the measurement is 0.005 nm and strain resolution is 5.7×10-6, due to the high sensitivity photodetection system.

A novel Electrooptical modulator with standing microwave electrode is designed and fabricated. This modulator is used to expanding optical spectrum width from CW laser. With the nonperiodic domain inverse method, the phase matching between light wave and standing microwave, and hence the large modulation are obtained. As an experiment result, the width of optical spectrum expanding is as wide as 2.5 THz.

The characteristics of the integrated optical acoustooptic tunable wavelength filter have been theoretically analyzed. A practical device with central wavelength of 1.523 μm has been fabricated on x-cut Y-propagation LiNbO3 substrate. The effective acoustooptic interaction length in this device is 16 mm and a TE-TM mode conversion efficiency of 99.3% has been achieved with only 35 mW of RF drive power. The tuning wavelength range is 140 nm with a FWHM of 1.6 nm. The over (fiber to fiber) insertion loss is -4 dB.

The variation relationships among resonant wavelengths, fiber parameters and grating period of long-period fiber gratings (LPGs) are studied. It is found that the high order cladding modes are quite different from the low order ones. Their resonant wavelengths are shifted toward opposite directions as the parameters vary. Ihis difference was confirmed by fabrication of two LPGs with period of 100 μm and 400 μm respectively. Some useful results for design and fabrication of LPGs are obtained.

Based on the coupled-mode theory, the transmission spectra of the phase-shifted long period fiber grating (LPG) are stuided. The imapcts of the inserted phase number, apodized function on LPG spectra are discussed in detail. A new scheme of optical add drop multiplexer (OADM) configuration based on cascaded phase-shifted LPG filter is proposed for flexible multiple wavelengths add-drop.

The sensitivity of intrinsic fiber-optic Fabry-Perot (F-P) magnetic sensor is studied and the influence of linewidth of light source is discussed. The results show that the linewidth is narrower,the sensitivity will be higher. When the linewidth and the length of F-P cavity are chosen, there is an optimum reflectivity. If reflectivity of F-P cavity equals the optimum, the magnetic field detected is the minimum and sensitivity is the highest.

The photon propagation in media volume has been successfully simulated by a Monte-Carlo method, and a genetic algorithm is applied to overcome the difficulties in the research of inverse problem by traditional optimizations and search algorithms casued by the discrete and statistic results of the Monte Carlo simulation. The reconstuction for a single optical parameter of a scatter media model and the simultaneous reconstructions for multiple parameters of model are realized well by the Genetic Algorithm and a detailed explanation of its mechanaism in reconstructing is presented.

Utilizing the cantilever beam mechanical tuning device developed by the authors both the center wavelength and the linear chirp of a 12 cm uniform fiber grating are tuned to compensate dispersion of 20 Gb/s transmission over 100 km standard single mode fiber. Experimental results show that the effect of dispersion compensation is favorable.

The equivalent Fresnel numbers of the regular polygon and slit are calculated by using the radius of inscribe circle and half-width of the slit as the feature length. The result can be obtained by incidence with uniform plane-wave.

A Nd:YVO4 laser at 1342 nm end-pumped by a high power linear-array fiber-coupled diode-laser is reported. An output power of 3.22 W at 1342 nm was obtained from x=0.7 of atomic fraction Nd-doped YVO4 laser with 13.30 W of incident pump power, corresponding to a slope efficiency of 25.5%. The output power fluctuation was less than 1%.

According to the equation which expressing the relation between the contrast of underwater image and the imaging range, and by changing the imaging rang experimentally, the figure of C-r for experimental data and the figure of C-r for theoretical calculation are compared and analysised.

The main points of design of 0.35 μm step-and-repeat projection lithography objective are introduced such as the determination of number aperture and structure model and the selection of material. The difficulties, novel design and a design result of lithography objective are discussed.