A liquid crystal neuron array with 8×8 neurons which can implement optical subtracting and thresholding parallel has been fabricated. It operates in parallel, that is, all the pixels of input are processed together simultaneously. The device is based on amorphous silicon photoconductor and features of liquid crystal rather than VLSI. So it can have higher aperture ratio, higher resolution and higher space bandwidth product.

Based on the concept of mathimatical morphology, the real time image differentiation taking use of the saturate property and image subtraction ability of electron trapping materials is performed by using a defocused convolver. This method shows many attractive advanteges such as high resolution, real time parallelism and incoherence. The thresholding and subtraction are performed by a single ET device.

In this paper, a new microscope pseudo color encoding method based on the pseudo color of optical source in the illuminating system was proposed. With the new pseudo color encoding method, color microscope images were obtained in the actual experiment.

A noval uderstanding on the mechanism of volume hologram was presented. Being different from the classical physical model with Bragg′s law, the new model is based on Fabry Perot etalon, i.e. a volume hologram is consisted of a series of coupled Fabry Perot. The advantage of multi beam interfernece results in the characteristics of volume hologram. Very good diffraction spectra were obtained from the new model based computer simulations.

The subaperture alignment technique for large aperture mirrors is presented. Wavefront sampling technique is employed to achieve the coherent combination of segmented mirrors, which have much smaller aperture but with higher surface quality. Hence larger aperture mirror with good performance can be obtained in this way. The mathematic descriptions of subaperture alignment technique are given. A demonstration experiment was done and the results were obtained.

Self mode locked operation is achieved in the femtosecond range by using Cr:LiSAF crystals without any active modulator or saturable absorber in the laser cavity. And with 900 mW pump power from an argon ion laser of 488 nm line, pulses as short as 40 fs are obtained at the repetition rate of 100 MHz and average output power of 45 mW.

A simple functions is derived which gives the maximum pump power for the single frequency operation of a diode laser end pumped standing wave laser in terms of the cavity geometry and materials parameters. It can be used as a practical guideline in the design of single frequency lasers.

High efficiency laser diode side pumped Nd:YAG laser is demonstrated. Under 100 mJ pump energy, the output of 39.5 mJ was obtained with the optical conversion of 39.5%. The experimental results were analysized for various laser parameters.

Spatiotemporal dynamics of a unidirectional ring oscillator with photorefractive gain is studied mnumerically. Some interesting spatiotemporal phenomena similar to that of in lasers are obtained in degenerate or quasi degenerate states. These phenomena include cooperative frequency locking, spatiotemporal periodic behavior and intermittence chaos.

The method of chaotic synchronization by coupling drive is proposed for Bragg acousto optic bistable systems, and the condition of chaotic synchronization in two systems is derived by the anylasis of the maximum conditional Lyapunov exponent. It is found that the chaotic outputs of the two systems is synchronized if one system is coupling driven appropriately by another. Numerical results show that this scheme of chaos synchronization resists noise and the synchronization can be realized even if the two systems are not identical. A practical method-non Pecora Carroll′s scheme-of chaotic synchronization is given for delayed differential system with a single variable. Experimental result is presented.

The linear relation of gain on carrier density in the conventional rate equation is replaced by the logarithmic relation (gain saturation effect) for quantum well (QW) lasers. The static and dynamic behaviors changes brought by this revision are analyzed. For longer cavity QW lasers, it is believed that the conventional rate equation is still a good approximation; but for short cavity QW lasers, the nonlinear gain relation must be taken into considerations. The calculations indicate that the spontaneous emission factor β and the modulation bandwidth will be overestimated in measurement or theoretical prediction if the gain saturation is neglected, especially for microcavity lasers.

The self pumped phase conjugation in BaTiO 3:Ce crystal was observed within a globular integrating cavity made of polytetrafluoroethylene. It was found that the self pumped phase conjugation produced by He Ne laser was enhanced under above circumstances. Some experimental results are analysed.

Under the nonlinear optical condition the all fiber optical bistability operation has been realized in an all fiber resonator consisting of Er Doped fiber and optical fiber couplers. The experimental bistability threshold is consistent with the theory.

Optical waveguide polarizers in visible light region632.8 nm have been fabricated in LiNbO 3 by proton exchange technology. Measuring setup are introduced. The polarization extinction ratio are calculated and analysed with physical optics and waveguide optics. The experimental results cincide well with theoretically calculated data.

An optical current sensing probe with completely closed optical path is designed, The formula which shows the relation between birefringence and the measurement are derived. Some important conclusions and experimental results are given. The sensing probe has been test run in a 110 kV substation.

The design of a new kind reflective field lens is introduced in this paper. This field lens has a particular effect broadening band in addition to the normal action of transmissive field lens in the optical system.

By using variational method, some conservative laws for the propagation of light pulse in bulk media are studied and the neccessary conditions for compression or broadening of a light pulse are obtained. It is possible to obtain light bullet from a light pulse without temporal spatial symmetry. By the impacts of temporal spatial coupling property spatial convergence of an optical beam may lead to the compression of pulse width.

A new method for ultrashort optical pulse train generation from a cw signal in the normal dispersion regime of optical fibers is suggested. It consists of copropagating a cw signal with a modulating pulse train at a different frequency in the normal dispersion regime of an optical fiber. The cross phase modulation, imposed by the modulating pulse train on the cw signal, can induce the generation of ultrashort pulse train from the cw signal. Numerical simulations show that the method works well under realistic practical conditions.

From the analogy between pulses propagation in time and the paraxial optics, the nonlinear Kerr media is approached by a time quadratic index media. The analytical form of the pulses propagation in this time quadratic index media is obtained. The characteristic of the pulse in media is analyzed and the ABCD matrices for the temporal domain is given.

The effect of positive and negative coupling between additive and multiplicative noise terms in a laser field is investigated. The fluctuations in the laser field is related to the property of coupling. The positive coupling between noise terms slows down the decay of intensity correlations, thus enhances the fluctuations in the laser system. While the negative coupling suppresses the fluctuations in the laser system and changes the system from stochastic process to deterministic process.

With 45 fs 2 TW Ti:sapphire laser system, the effects of laser intensity and gas density on the high order harmonic generation were studied. The highest order harmonic up to the 25 th(31.4 nm) in argon was observed.

Stark modulation electric rotation laser spectroscopy (SM ERS) was used to separate the electric rotation signal produced by the accidental degenerate transitions from the nondegenerate transitions. It can simplify complex and congested electric spectra and is very valuable for measuring perturbed polyatomic molecular spectrum. In this paper the semi classical theoretical model of this technique is presented. As an example, the NO 2 SM ERS spectrum and their main character was analysed by perturbation theory.

We measured the emission spectra, absorption spectra and the exited state life time of Cr 4+ :YAG and Cr 4+ :Mg 2SiO 4 crystals at room temperature and liquid nitrogen temperature respectively. The variation of the integral fluorescent intensities at the two different temperature was obtained. Considering it with the variation of the exited state life time, we could draw a conclusion that in the range of 77 K to 300 K, the influence of temperature on the emission cross section of Cr 4+ is relatively small. The change of the fluorescent intensity is mainly because of the change of non emissive relaxation rate with temperature.

The dielectric functions of the strained Si M/ Ge N superlattices have been measured by using spectroscopic ellipsometer in the 2.0～5.0 eV photon energy range. The observed results were analyzed by fitting the second derivative spectrum of the dielectric function. The new superlatticelike transitions are observed in addition to the typical E1 and E2 transitions.

The spectra of the laser pulses output from a short cavity dye laser (SCDL) and then amplified by a dye laser amplifier were observed experimentally. The major spectral parameters of the laser spectral of the longitudinal modes (LM) were measured. The change in spectral features including spectral envelope, frequency pulling, and number of the LM etc., are compared. Under certain conditions, the dye amplifier can produce one or more new LMs in the multi LM amplification, while in the other cases, the number of the LM output from the amplifier remains unchanged. There are striking resemblances between the new LMs and the initial modes, for example, the new modes have properties in frequency pulling, collinear and codirection propagating. In the mode coupling and generating there exists frequency pulling, this implies that there is photon frequency mismatch and photon energy unconserves in total resonant four wave mixing (FWM) in dye amplifier.

A formula of the equivalent medium theory for three component metal dielectric inhomogeneous composited material is derived on the bases of the equivalent theory for two component metal dielectric inhomogeneous composite material. The new formula is used to calculate the reflectances of the sample of Au Cu Al 2O 3 and Ag Cu Al 2O 3 electrolytic coloured anodic aluminum oxide films. The calculated results are in agreement with the experimental results. It indicates that the new formula is useful at certain conditions.