The dynamic relationship of Zernike modes in an adaptive optics (AO) system using direct-gradient wavefront control algorithm was established. By comparing the power spectra rejection function of those Zernike modes that describe the atmosphere disturbed wavefront, the phenomena of different compensation effect for those Zernike modes in an adaptive optics system using irect-gradient wavefront control algorithm were indicated and the reason of causing different compensation effect was analyzed. The theoretical results were verified using the experimental results on a 61-element adaptive optics system.

According to the experimental results from atmospheric surface-layer and turbulence cell, a cubic model of ellipsoid depicting large-scale structure is put forward. The effect of large-scale structure on wave-front during light transporting is computed and analyzed, and compared with the small-scale effect. On the same parameters of model, the effect on phase structure function of wave front is a little larger when ray is parallel to the discontinuous plane than ray is perpendicular to the discontinuous plane. Generally, the effect is small, but when the large-scale structure is one-dimensional and ray goes parallel to the discontinuous plane, the effect is large.

The influence of dispersion ripple of fiber gratings on chirped CATV signals′ carrier-to-intermodulation ratio (IM) is investigated. The value of IM is related to the amplitude and the period of dispersion ripple. The number and the distribution of channels have an effect on the IM value. It is found that the uniform linearly chirped grating can not be used in CATV systems.

The performance of Stimulated Brillouin Scattering (SBS) suppression is one of the key parameters in optical fiber AM-CATV (amplitude modulated cable television) externally modulated transmitters. The influence of the incident polarization state with TE mode and TM mode on the performance for SBS suppression in optical fiber AM-CATV externally modulated transmitters is analyzed theoretically. The analysis and calculation have shown that the TE mode is the best mode for performance of SBS suppression. The influence of the incident polarization state deviating from TE mode is also analyzed and calculated. And it is shown that the deviation angle from the TE mode should be less than 10 degrees so as to the performance for SBS suppression will not be degraded.

Based on the Kukhtarev’s model and the Moharam’s field function exact steady state analytic expressions for dynamic grating envelopes are deduced for any constant values of light modulation depth and light excitation efficiency. Furthermove the diffraction efficiency is considered for nondestructive readout.

A new opto-electronical network with the function of adaptive thresholding is proposed. According to the input modes, it can adaptively adjust the threshold value of the system through competition among the net units. As a result, the threshold is always equal to the maximum input. So the function of WAT (winner-take-all) is achieved. The system is mainly composed of a-Si PIN photo-electrical detector and WTA electrical network. With parallel processing, it permits rapid response, high sensitivity, better addressing capability, simpler structure and stable performance, etc. It can be conveniently applied to opto-electronical systems such as adaptive thresholding, correlation peak detecting and associative memory. A specific network with 36 units is analyzed and the experimentce results are presented.

The cascaded neuron network model is used to recognize 3-D targets. In order to improve the recognizing rate, several methods of choosing the construct and algorithm are proposed. They can be used together or solely according to the requirement. The invariance encoding, the algorithm, the binarizing of the interconnection weights and the selecting methods of the training samples, and so on are studied. The computer simulation of recognizing three plane models is completed based on this cascaded neuron network model. The recognizing rate of the model is over 96% as the three planes arbitrarily positioned and directed.

An inverse evolution method for studying nonlinear dynamics of an object is suggested. Its main process is to deduce a probability differential (or partial differential) equation to the object using known solution from non-differential equation, therefore the solution domain or space would be extended, in other words, those lost solutions are restored. Meanwhile its application to Fabry-Perot (F-P) interferometry is discussed in detail (also suitable to Mechelson interferometry). A new parameter definition, opaqueness of F-P, is recommended, then one can deduce the dynamic property of F-P and get other methods for measuring the fineness and optic phase of F-P. It is worth to note that not only an extended solution space is contained in the differential equation but also one can further in phenomenon infer it according to the known typical nonlinear evolution equations or current experience and knowledge, hence the representation for object would be more and more close to its true state.

By using a special Ronchi phase grating and polarization phase shifting method, four phase shifted patterns can be captured simultaneously, and thus the dynamic phenomena can be measured. This technique is used in a Mach-Zehnder interferometer and a speckle interferometer, the refractive index changes and the off-plane displacements are measured respectively, the experimental results are given.

By use of the Monte Carlo method, the variations of diffusive reflection with time are obtained in a scattering medium inclusive of the inhomogeneity. The variations are different when the relative position of the inhomogeneity and the light source is defferent. With combination of the difference and time-gate methods, the image of the sphere embedded in the depth of the scattering medium are acquired. The results not only show that the contrast of the image is directly related to the start-of-gate time and time-gate width, but also show that according to the brightness and darkness of diffusive reflection in the sphere projection area, the point of 80% or 50% of the maximum diffusive reflection intensity should be judged as the boundary position of the sphere.

A new algorithm by iterative least-squares fitting in phase shifting interferometry is presented. If the reference mirror has tilt and piston errors caused by phase-shifting, the phase shifts of the pixels along the same interferogram are not a constant, but they are still kept on the same plane. So solving this plane can eliminate the errors. The first order Taylor series expansion replaces the non-linear equation used in solving this plane, and thus simplifies the algorithm. By iterative, the accuracy can be guarantied. The validity of this algorithm has been examined by means of computer simulation.

The dependence of ranging performance for an airborne laser range finder on atmospheric transmittance and background noise is theoretically analyzed in accordance with the range equation for the diffuse reflecting target. Based on LOWTRAN7 code, the dependent relationship between them is numerically calculated and discussed. The numerical result can be used as the basis for design and test of the range index for an airborne laser range finder.

A theoretical model was developed to calculate small signal gain, and was used to investigate the influence of focusing condition on the small signal gain for longitudinal pumped Cr3+:LiSAF6 laser. We optimized the small signal gain of Cr3+:LiSAF6 crystal, obtained optimum values of waist radii and focus positioons under given pumping powers. The calculated results proved that the optimization greatly improved the small signal gain perforonance of Cr3+:LiSAF6 crystal.

In the experiment of actively mode-locked fibre ring laser,the output pulse with 2 continuously tuned wavelengths is obtained by means of the dispersion compensation fiber to increase the cavity dispersion and adjusting the modulation frequency.17-wavelength laser is demonstrated by cooling the erbium-doped fiber.

The different photoelectric signals in bacteriorhordopsin are experimentally measured when it is excited by 10 ns pulsee lasers at 1064 nm, 532 nm and 355 nm. 532 nm pulse laser is used mostly as pumping light to measure the photoelectric signals affected by the impedance of the measuring circuit. The mechanism that bacteriorhodopsin generates photo-charges and the photo-charges transfer in it was studied and analyzed. The results show that the positive and negative photoelectric signals are produced by the shift of the positive and negative charges respectively, and more energy is needed to produce positive charges than negative ones. At the same time, the positive and negative charges not only have their own transfering characteristics, but also affect each other, such as, positive charges move slowly, and negative ones fast, moreover, the negative can pull the positive to move forward, which, together with the interface between the sample and electrodes, cause the magnitude and width of the pulse photo-voltage having special dependence different from other photo-electronic devices on the linked resistance.

Assuming the requirements of optical design and the precision of the optical manufacturing are satisfied, the key of high imaging quality in an optical system is to assure the accuracy of alignment after assembling all the mechanical components. In accordance with a three-mirror off-axis aspherical system, a new way is put forward. Autocollimating interferometric measurement at multi-field of view is used to get a set of aberrations representing the system misalignments. The aberrations are regarded as the revised target. A least-square computer optimization algorithm is used to predict mirror adjustments. Once the misalignment is determined, it is proved the feasibility of correction theoretically. The theoretical and the numerical analysis are given. The results demonstrate the possibility and effectiveness of this computer-aided alignment method.

The red organic light-emitting devices (OLED) are demonstrated with the electroluminescent layer consisting of aluminum tris (8-hydroxyquinoline) (Alq3) doped with the dye DCJTB, while the emission color dependents on the concentration of DCJTB. A peak emission wavelength shift up to 30 nm due to strong polarization effects is found. A maximum luminances of 17400 cd/m2 and 2900 cd/m2 are measured for 0.2% and 3% in Alq3, respectively. A 20 mA/cm2 luminances of 1080 cd/m2 and 150 cd/m2, and quantum efficiency of 2% and 0.4% are obtained.

The metal oxide semiconductor films have been used as sensing medium in the opto-chemical sensor based on surface plasmon resonance. The influence of the optical parameters of Ag and sensing films on the sensor sensitivity is analyzed. By optimizing the optical parameters of intermediate layers between the metal films and the sensing films, the sensitivity can be increased further. Experimentally, SnO2 and SiO2 films were selected as sensing and intermediate layers and the gas sensing tests to NH3、C2H5OH and C3H8 were made. The results indicate the sensor with optimized structure has a higher sensitivity.

The tunable grating filtering detection system of fiber grating sensor is investigated theoretically and experimentally. The theoretical expression of the wavelength resolution is presented. The optimum theoretical wavelength resolution of the system is 0.8 pm. Due to the excellent performance of the photoelectric detection system, the measured wavelength resolution of sensing detection is 2 pm and the strain resolution is 1.7 με in the experiment.

A polarization-modulated fiber-optic sensor with a single sensing head for the simultaneous measurement of two parameters is presented. The possibility of the separation of two parameters from a sensing head is analyzed theoretically. Through optical components arranged properly, the sensing head can simultaneously output two signals which can represents two different physics parameters. The experimental results verify predictions and show that voltage and temperature, or force and temperature can be simultaneously measured by using only one of this kind of sensing head. Under lab condition, when the temperature changes from 20 ℃ to 110 ℃,the force output with the temperature stability of ±0.1% within the range of 0～80 N and the voltage output with temperature staility of ±0.5% within the range of 0～10 kV can be obtained, while the accuracy of the temperature detection is ±1 ℃.

A new method is proposed to design coding gray-tone masks based on modifying position and shape of cell on mask. Pre-distortion applied to modify mask has been implemented by introducing this method according to the nonlinear effects in aerial image and resist development. Based on the theory of partial coherent light imaging and the resist development model, the intensity distribution through the coding gray-tone mask and exposure of photoresist have been simulated. The coding gray-tone mask was fabricated by e-beam exposure system and microlens array with continuous relief distribution on photo resist was obtained.

A new analytical model for photoconductive semiconductor switches (PCSS) is proposed considering the surface and bulk recombinations, the carrier-carrier scattering and the negative differential effect of the carrier drift velocity in their transport process, Dembet effect, optical reflection and attenuation with depth during the optical action. Some important parameters characterizing PCSS, such as on-resistance and switching efficiency etc, have been simulated. Also the waveforms of the switch current and output voltage have been obtained. The calculations show that the relation between photo-conductance and incident ligh intensity is not strictly linear but nonlinear in what is called linear operational mode of the switch. The good agreement has been obtained by comparing the calculation with the experimental data.

A BBO nonlinear crystal was used in the experiment. A pair of light quanta called signal and idler light quanta is produced through the nonlinear process of type Ⅰ spontaneous parametric down-conversion with Ti:sapphire femtosecond pulses. The fourth-order interference phenomena was observed and the correlation behavior of the two-photon entangled state was demonstrated.

A scheme is presented for generating atomic entangled states through the interaction of the two-level atom with a coherent state cavity-field. Under certain condition, the atomic entangled states with controllable weighting factors and four Bell’s bases of the entangled two-atom are obtained.

The concept of entropic squeezing is established and the entropic squeezing of the field interacting with the atom is investigated by regarding the entropy as a measure of quantum fluctuation and according to entropy uncertainty relation. The results show that the entropic squeezing is a high sensitive measure for the squeezing effect of the field.

The remote displacement measurement was realized utilizing laser Doppler effect. The Doppler shift of differential structure was analyzed theoretically. The displacement measurement system of double-beam differential acoustooptic modulating structure, large aperture collection of backward scattering light and real-time compensation of the losing signal by computer tracking software was designed. The displacement measurement of paper and metal at a distance of 10 meters was made with an accuracy of ±0.4%.

The influence of core size, relative refractive index difference, stress and bending radius of silicon-based silica waveguides on polarization was analyzed. Conclusions were drawn as below: the birefringence of square waveguide with small relative index difference is small. The birefringence caused by residual stress is larger than that by core size. Small bending radius causes high birefringence and loss, so large bending radius is preferred within the permission of chip size to reduce birefringence.

A new method of big shearing digital speckle interferometry is presented. Grating is placed in image space of objective lens, and used as the shearing part. Light wave from reference object and measured object interfered at the image space. The principle of this method is discussed in detail based on Fourier optics, and plane displacement of typical specimen is measured which is a peripheral region fixed block board having symmetrical load. The results show that experimental value and theoretical value are fit well. Some applied example are given. Theory and experience are shown that this method not only have the high sensitivity of holographic interferometry (λ/4), but also have merit of low shockproof demand and in-site measurement.