17.8 ps coherent optical uitrashort pulses were produced with a side mode snpp ression ratio of 38 dB from short coupled cayily scmicorductor laser by directly modulation, and its peak output power was 130 mW.

Quantitative calculations of the do-excitation rates have been done for Ti:Al2O3, Cr:BeAl2O4 and Nd:YAG lasers pumped with xenon lamps. The results indicate that this de-exeitation effect can produce about 30% and 18% decrease in excited population for Ti:Al2O3 and Nd:YAG, respectively. Whereas this effect is negligibly small for Cr: BeAl2O4 crystals and the like (Cr:GSGG, Cr:GGG).

A PIV technique which uses the near forward scattering light from particles was developed, which has the ability of measuring instantaneous two dimensional velosity distribution of fluid flow field, light intensity can bo increased greatly and no limitation to the measurement result by the depth of field.Experimental comparison of two PIVs techniques was made.

A new explanation of operation principle about RFC polarization-state control device is presented, which includes the effects of twisted fiber.

An asymmetrical heterodyne laser pro bo system used for detection of microvibra-tion is described. The experimental results show that a high sensitivity of about 1X 10-4 nm/ Hz has been obtained. By this system, the microvibrations of thin film circuits driven by alternative voltages and the radiated aooustie field distributions of SAW focusing transducers were detected with satisfactory results.

The pnolse photoaooustie spectrum of SiH4 molecules has been obtained in the range from 926.96cm-1-1084.72cm-1, corresponding to the lines of CO2 laser. The speed of sound travel in the system has been measured by the method of phtoacoustios.

In this paper a, simple method for measurement of three-dimensional displacement is proposed that avoiding shock proof table, double exposure of complete-wave hologram are made. The processed films are placed in a coherent optical Fourier transform apparatus to measure three-dimensional displacements. ISO-thetic fringes and the displacements of body are determined simply and accurately.

Metastable structure and structural changes of Cu-Ag, Cu-Al, Ag-Al, Cu-Ag-Al alloy films prepared by co-evaporation, onto cooled substrates have been, investigated systematically, and some unique phenomena are exhibited in the amorphous formation and crystallization. It is generally observed that the as-deposited amorphous films tend to present homogeneous solid solution with fcc lattice at the first step of crystallization, and undergo a step-by-step structural change proceeding before reaching the final equilibrium states. The laser induced crystallization of amorphous Cu29, Al71 film also shows such a unique behaviour, and it makes us propose that the above alloys may be the promising candidates as phase change optical storage materials.

Laser melting and solidification process on the surface of ZL109 cast alloy gamples with various coating layers has been investigated by using a 2 kW level, continuously adjustable transverse-flow CO2 laser. The experiments indicated that the wear-resistance of the treated samples is 2-1 times that of the untreated ones.

A laser rainfall measurement equipment is described. The sampled data of rainfall measurement are given. Its feasibility is discussed comparing with the tipping-bucket rain gauge. This method can be used to inspect particle flaw in the transparent medium.

The variation of laser gain is discussed under the condition that there is a small angle relative to the propagation directions between the electron beam and the axial line of the wiggler in free-electron lasers and the maximum permissible angle is given.

A CW tunable dye laser and a homemade Kr-U hollow cathode discharge lamp were used to measure the optogalvanic spectrum of 81 U spectral lines in the wavelength range of 562-615 nm.

Based on study of large signal four-wave mixing, we obtained the relation ship between the conjugate wave phase and the signal wave phase, and furthere proved the limitation of phase distortion compensation by four-wave mixing.

A model is analyzed and developed for the probability density function of phase fluctuations of the laser beam scattered by rondom raugh surfaces and propagates through atmospheric turbulence. The scattered field of the laser beam is modeled as doubly stochastic statistical model.

This paper presents & formula of the differential cross-sections and the summation rules related to the processes of the e-H inelastic scattering in the presence of a low-frequency laser field. Detailed calculations are performed and the results are discussed.

We analyses beam quality and compensation efficiency in the case ol finite correct-element size by using the deformable mirror as a spatial filter. Although the StrehPs ratio increases as the subaperture size reduces, it reduces very slowly when the size is small. Based on our theories the optimal size can be easily determined for high performan-ce-to-eost ratio. In order to compare with experimental results we have introduced concept of compensation efficiency. The calculations reveal that the compensation effciency is low for very weak turbulence. It increases at the beginning while turbulence becomes stonger. But it rapidly decreases after reaching the maximum value. Theese conclusions support the previous experimental facts.

Spectral properties and photon-gated spectral hole burning of Sm2+ in SrBa (SO4)2 mixed crystal are reported. The inhomogeneous broadening of 5D0-7F0 transition of Sm2+in this material is extended to lnm(766G-Hz). Using the output oi Ar+ laser at 514.5nm and the output of the CW dye laser at around 632.8um, photon-gated spectral hole burning at 7F0-6D1 transition at 5K was observed and the electron energy level and relevant fluorescence and excitation spectra of Sm2+ in SrBa(SO4)2 are given.

The Eaman enhanced nondegenerate four -wave mixing (RENEWM) in benzene and methylbenzene was studied, the spectra suppressed nonresonant background of BENFWM was obtained. A comparison between the experimental result and the fitting of curve have been made.