The virtues and the ways of laser imaging for underwater target are described. A kind of underwater experimental system with micro-intensified CCD imaging and continuous blue-green laser-spot scanning is discussed, The physical model and computer formula of the system are analysed. The experimenu show that when it works under the contrast limitation model, its [1+(cos θ)/3]CRmax (ie. attenuation length-AL) value kept eontant. When water quality and target are certain, the value may become a basis for criteria of system suporiority.

Based on the smooth perturbation theory, a general expression of normalized spectrum for Gaussian beam and an analytic formula of normalized speetrum for collimated or spherical beam in a homogeneous path are given. Caleulation shows that there is a peak frequency in these spectrums and the frequency depends on turbulent outer scale and transversal wind. According to this eharaeteristie the outer scale is remote sensed successfully by using the atmospheric eoherent length measurer. At the same time five three-cup anemometers distributed evenly on the path are applied to measure average wind. Experimental results indicate that the outer scale is varied in the range of 2.6～7.0 m at the altitude of 8 m above the ground and the average value is 4.9 m.

The characteristics of the negative chirp pulse transmission along normal dispersion fiber was analysed by numerical method and measured experim ently. The numerical results were close to the experimental results. The resups showed that the pulse width and spectral width could be compressed when the positive chirp pulse propagated along normal dispersion fiber. The fundamental and high-order optical soliton transmission were demonstrated by using normal dispersion fiber elimination chirp.

The finite element mothod was used to analyse the birefringenee of the new-type mierohole fiber which consists of D-shaped micro hole and two circular stress in the cladding of the fiber.

We use the equal-attenuation-vector method, to numerically study dispersion characters of dark spatial soliton induced waveguide under limited background. The results are different from that of infinite background dark soliton induced waveguide. But when of background is wide enough, the difference can be neglected. The study will be useful to the utility and design of all optical soliton induced waveguide.

A Hermite-Gaussian expansion is used to calculate the optical wave propagation between the planar waveguide and the reflector. The coupling losses in planar waveguide resonators are calculated and the coupling losses for the EHo mode of different planar waveguide as a function of mirror curvature and position are presented. It is shown that there exist two special geometries having low coupling losses.

Optimization and analysis of computer generated holographic phase grating with large even spot arrays are made using a novel simplify synthetic optimization method. Diffraction efficiency with one demension is 80.1%， and non-uniformity is less than 0.3% in theory. A 64×64 computer generated holographic phase grating splitter used in optical interconnect module is fabricated.

With optical fiber image plane hologram，the hologram of higher diffraction efficiency can be obtained and larger object image can be reconstrueted. The influence of the single fiber core diameter size of image-carrying optical fiber bundle on the outlet optical field under the excitation of coherent light is analyzed. The different effects of low-order modes and high-order modes in the outlet optical field on hologram are discussed. On the basis of above, it is suggested and verified experimently that the diffraction efficiency and resolution of optical fiber image plane hologram can be improved by decreasing the single fiber core diameter and increasing the number of the single fiber of image-carrying bundle.

A statistical trinary clipped model based on minimum energy is eonstrueted by using statistical method. This model removes the difficulty of the Hopfield model in displaying the interconnection weights with a lot of levels of grayness，and improves the storage capacity and address ability comparing with the clipped model and the trinary clipped model.

A new method of multi-objeets rotation invariance classfieation is presented. The principle of object rotation invariance clssification is many-to-one associative memory model. In order to implement easily with optoelectronical techniques and to use the time- and space- bandwidth products sufficiently, unipolar model and a binary interconnection weights are used. To overcome the shortcoming of low storage capacity caused by unipolar model, a distributed thresholding is employed. Because of associate memory model cascaded WTA model by a suitable associate memory codes, the storage capacity and error-tolerant ability of the system are improved. The results of computer simulation are given and an opto-electronics system is presented.

Based on the assumption that the vibration effect complies with Gauss distribution, the effect of blur-vibrating on the reconstructed image of Fourier transform hologram is analysed, A criterion for determining whether the hologram can be fully reconstructed is given. The experimental result and computer simulation support our conclusions.

With several kinds of cylinder cavity targets irradiated by 1.053 μm laser and using a spatial imaging technology, the spatial-resolution images of the jet of plasma at the laser entrance hole, inside of the cavity and X-ray transport channel are obtained. The spatial character of the jet of laser produced plasmas are observed.We also made observation on the jet of plasma using a planar target and a converting target of special geometry·A typical result in the experiment is given and discussed briefly.

An exact integral solution of Maxwell equation for uniform plasmas is studied. In ultrashort pulse ease, the 1-D laser pulse evolution expression is obtamed by means of the integral solution.

A well-defined n=1 heavy-hole exeiton absorption peak from a loealized state and n=2 heavy-hole exeiton emission peak was observed in a ZnCdSe/ZnSe single quantum well structures at 77 K. The localized state was formed by fluctuation of well-barrier interfaces. Stimulated emission was observed from the localized state. The gain originate from exeiton phase space fill of these state. An optical excitation threshold around 116 kW/cm2 was measured. The gain switching was observed. These results were obtained from photoluminescence under oaring excitation power, and luminescence decay experiments.

The diode laser side-dumped 100 Hz E-O Q-switch TEM00-mode laser is studied. The pump source was a quasi-CW 100 W diode laser array. A eylindrical lens was used as a coupler between the diode laser and the Nd:YAG thin slab with the trapezoidal section. The laser resonator is a plane-concave cavity with a curvature radius of 3 m. Using KD*P Pockels cell, the laser produced 2.37-mJ/pulse, 7-ns pulse width, M2=1.1 beam quality and 100 Hz pulse repetition rates. Optics-opties efficiency and slope efficiency of the Q-switch laser were 8.5% and 18.9%, respectively.

A 3 w diode end-dumped Nd:LM A laser operating at 1054 nm and 1083 nm, respectively, is reported. The output power of 620 mW with slope effieieney of 500% and total optical efficiency of 20% at 1054 nm and the output power of 64 mW with slope efficiency of 6% and total optical efficiency of 2.1% at 1083 nm are obtained by three-mirror folded astigmatism compensation eavity.

Absorption spectra of soluble vanadyl phthaloeyanine Pr4VOPc (vanadyl phthaloeyanine with four propyl groups) in different medium were studied. Absorption due to the Pr4VOPc molecular monomers (λmax=706.0 nm) is dominant in dilute Pr4VOPe-chloroform solution. Absorption peak of the sublimed Pr4VOPc film is at 720.0 nm; whereas Pr4VOPc in solution east solid film shows a strong diffused absorption band ranging from 650.0 nm to 850.0 nm. In PMMA， absorption due to the molecular dimers is dominant (λmax=660.0 nm). This difference is caused by the great sterie effect between Pr4VOPc molecules. Pr4VOPc with strong near-IR absorption can be made by heating sublimed Pr4VOPc film or exposing it to organic solvent vapor. While only organic solvent treatment can make Pr4VOPc non-crystalline phase I in PMMA matrix change into crystalline phase II.

The optical absorption spectrums, level structures and upconversion luminescence of Pr3+ sensitized by Yb3+ in fluorozirconate glass are studied. The results show that Yb3+ ions transfer energy to Pr3+ ions by the energy resonance translation between rare earth ions; the intensity of the upconversion luminescence is the highest when the glass is excited by 880 nm-wavelength light; the intensity is high both when the concentration of Yb3+ is low while the concentration of Pr3+ is high and when the concentration of Yb3+ is high while the concentration of Pr3+ is low.

The strong coherent laser can couple the discrete states, which changes the eigenstates of the atoms. It make some forbidden transitions possible. By this way we give a new direction of the generation of the 3rd harmonicwave of the krypton and compare its conversion efficiency to the normal one.

The high order harmonic generation by two-colour coherent laser fields of arbitrary polarization (1ω plus 2ω or 3ω) is studied systematically. The results show that a single circularly polarized field can not emit high harmonics, under some conditions some order harmonics can be enhanced and some can be eliminated or decreased. The high order harmonic generation has a strong dependence on the ellipticity of the fundamental field and the mixing of different fields.

It was found that self-lignment of hemicyanine molecules existed in the unpoled hemicyanine doped silica film fabricated by sol-gel technique. A χ(2) value of 6.6 pm/V was obtained for a 50 nm thick film. Time evolution of hemicyanine structural changes and their influence on second order nonlinearity were investigated. It was found that transfer of protonated hemicyanine to monomeric and aggregated hemicyanine occurred within 4 hours after film deposition, during this period of time SHG signal continued to rise and reached maximum final1y. Blue shifting of both aggregate and monomer absorption peaks were found accompanied with the drying of the film.

Using the theory of classical electromagnetic field and the concept of the effective (supper-) exchange field, the magneto-optical effect and its temperature dependence in paramagnetic, ferromagnetic, ferrimagnetie and antiferromagnetic media are deduced. Theoretical analysis shows that Faraday magnetooptical effect has the anisotropy, and Faraday rotation is depend not only linearly on the magnetization Min paramagnetic and ferromagnetic media or the sublatbee's magnetization Mi in ferrimagnetie and antiferromagnetie media, but also on the high-order terms of M or Mi.The (super-) exchange interaction is an importaut factor leading to the complicate temperature dependenees of magneto-optical effect and its anisotropy. The theory interprets the experimental results satisfaetorily.

Optical third-harmonie generation (THG) in the poly (N-vinylearbazole) (abbreviated as PVI)-fullerene combination films has been studied by using a 50 pieoseeond Nd:YAG laser as the fundamental light source at 1.06 μm. THG enhancement is observed in the PVK/C60 multilayer and mixed films compared with pure PVK and C60 films. Considering the charge-transfer (CT) process between these two materials, we attribute this third-order nonlinearity enhancement to the change of dipole moment and susceptibility caused by the carriers generated by the CT process in multilayer film. But in mixed film, the CT complex plays an important role.

A ferroeenyl derivative of 1-ferroeenyl-2-(4-nitrophenyl) ethylene was synthesized by phase-transfer Wittig reaction. The solvatoehromie property of the molecule was studied using ultraviolet. The second-order molecular polarizability was determined by de electric field induced second-harmonie generation (EFISH) experiments. The molecule's β is to be 32.1×10-30 esu.

Based on thermal nonlinear optical effect，the dark spatial optical solitons stimulated with a strong CW laser in the toluene solution of C6o are studied. The results of the experiment and numerical computation are given.

The resonance Raman effect is produced in liquideore optical fiber. The intensity of Raman spectrum can be increased by 109 times. Both absorption peak and concentration of the sample exert effect on intensity of Raman speetrum. The optimal optical fiber length depends on the sample eoneentraion.

This paper presents a novel scheme of laser beacon which employ the FADOF as frequency selecting device. By appling electronic and optical feedback to control beacon system，the stability, reliability and ability of overcoming interferenee of laser beacon could be enhanced. The system could also be initiated automatically. The frequency stability of the laser beacon was better than 5×10-9, and the LD frequency of the system could be stabilized at any peak of FADOF within 30 ms.This scheme could meet the need of novel pointng，aquisition and tracking (PAT) system using FADOF，and will have a big influence in buiding laser communication link betweeen satellite.

The mechanism of using fiber Kerr gate regenerator to suppress the additive noise and timing jitters of input optical signal is discussed. Influences of parameters of different components in the regenerator on the abilities of pressing noise in input signal are analyzed. It's shown that the regenerator can greatly suppress noise in communication system and improve its communication capacity by choosing suitable length of DSF in I}err gate according to the noise characteristics in system.

The beam propagation method(BPM)is used to simulate the eharaeteristies of waveguide intensity modulators. The relation between output and parameters, such as channel waveguide width, Y type angle and voltage, are presented.

Based on the principle of dispersion compensation with linearly chirped fibre Bragg grating (LCFBG)，the different capability of LCFBG varying the quasi-Gauss head coupling profile was analysed. A design is presental which can make the LCFBG provide both strong ability of dispersion equalization and smoothed broad bandwidth GVD curve with depressed sidelobes. The influence of relative parameter to the GVD curve is discussed.

The influence of the quartz, which acts as the sensing element of the fiber optic voltage sensor, on the perfermanee of the sensor is studied. Both theoritieal analysis and experimental results show that the fluctuation of the temperature brings about the undulation of the characteristic of the sensing crystal and the variation of the stress applied to the crystal, causing the consequence that the long-term stability of the sensor can not meet the requirement of measurfing aeeurey of 1%·

Because the aperture stop (exit pupil) is normally outside of the eyepiece optical systems，it's especially difficult to correct the distortion of the optical system. The best way to eliminate the distortion is to use aspherieal surface. The novel design of the optical system with aspherieal surface of a wide angle eyepiece is described by the third-order aberration theory. The designning resups and data are given.

The efficiency improvement of free electron laser (FEL) by increasing wiggler magnetic field is inverstigated. Numerical simulation shows that inereasing wiggler field can increase FEL efficiency from 12.9% of uniform wiggler to 17.6%. It is interesting that if the wiggler field is tapered after being increased, a FEL efficiency as high as 43.3% can be obtained.

The influences of the correlated two-mode SU(1,1) coherent state interacting with a three level cascade atom on the atomic dynamic behavion are discussed. The time evolution of the quantum statistic properties of two-mode field is investigated. Some new phenomena of the system are found.

A new technique of fringe analysis is proposed to measure the 3-D objest shape. A grating pattern is projected onto an object，and the grating pattern deforms in accordance with the 3一object shape. T his deformed grating image is analyzed by means of subfringe integration algorithm·T he phase distribution and profile of the object shape are given.

The performance of low-threshold and high-efficiency Nd:S-FAP laser at 1.328 μm has been realized by using xenon flash lamp and tunable dye-laser (570～600 nm) pump respectively. The centre wavelength of frequeney-doubling laser is 664 nm and the linewidth is 1.3 nm. When the transmission of output reflector is 7%，for xenon flame pump the threshold energy is 240 mJ and the slope effeieney is 0.85%, while for tunable dye-laser pump, the threshold energy is 4.5 mJ and the slope efficiency is 38%. The laser characteristics, such as the emission spectrum, the polarization, the devergenee angle and the output energy in different cavity length were given.

Dimond film was cut by a Nd:YAG laser and the ablation rate and characteristics were studied. An ideal condition of ablation for dimaond film was discussed.

The Needle method of coatings design method, overcomes the shortage of the conventional optimum methods which always meet too many local minimum. It makes the merit function decrease by insert new thin layer. Design can start with one layer chosen randomly. The methematical model and explanations of this method are presented.