Analyses are made of heat and pressure induced optical distortions in high power gas lasers.And compensation for these optical distortions is presented. The perturbation stability of a resonator to the geometric parameters is discussed, and the misalignment sensitivity of the optical resonator is also studied. An analysis of the design is demonstrated of a stable concave-convex resonator with large fundamental mode volumes.

The experimental results on transmission spectra of CuCl microcrystals in the near ultraviolet and visible regions are reported.The transmission spectrum of CuCl microcrystals under He-Ne laser irradiation is also shown. A sharp peak with a width of 0.64 μm in the transmission spectrum at 389.08 μm is observed.

In this paper, the fundamental principle and fabrication method for obtaining high efficiency diffractive gratings are described. Experimental result shows that the firstorder diffractive efficiency of a four-level staircase grating is 68%.

An interferometric technique with double-frequency grating used to measure the thermal lensing of a Ti: sapphire rod pumped with Ar+ laser axially is presented.The experimental results concerning the thermal focal length variation with pump power are given.

In this paper a laser stabilizer using double feedback signals is proposed. It is proved theoretically and experimentally that this method makes an order of magnitude improvement in reducing the laser noise for the optical stabilizer.

This paper describes a polarized multichannel camera designed for measuring thermal deformation fields. The whole information of thermal deformation fields can be recorded on a single spechlegram and obtained by filtering via the appropriate halos.

A novel micro-optical crossover interconnection package has been proposed.The optical crossover switching network where asymmetric Fabry-Perot reflection modulator arrays based on multiple quantum wells are used as electrical addressed four-function interchange nodes is described. The micro-optiCal interconnection package features stability high speed, small weight, and ease of intesration.

A 2 kW CO2 laser was employed to clad a TiNp/Ni-alloy composite coating onsteel 1045.The microstructure and sliding wear property of the cladded layer were analyzed. The dilution of the TiNP-reinfored coating under different laser processingconditions was discussed. The cladded layer exhibits TiN particles,γ-Ni primary dendrites and the eutectics of γ-Ni+(Fe,Cr)23(CB)6 in the interdendritic regions. High density dislocations in γ-Ni primary dendrites and a large amounts of stacking-fault within (Fe,Cr)23(CB)6 phase are obseved. Partial dissolution appearing on the edges of original TiN particulates and their regrowth in the form of independent fine dendrites during resolidification are found in the cladding region. The addition of TiN particulates into Ni-alloy coating greatly improves the wear resistance of the composite coating by increasing the microhardness without distinctly increasing the friction coefficient of the composite coating.

In this paper,the experimental results of a Nd:YVO4 laser longitudinally pumped by LDA are reported.The optical to optical efficiency and slop efficiency are 23.6% and 28.8% respectively at 6% output coupling.The starting performing characteristics of high-order transverse mode are investigated experimentally and analysted qualitatively.

The mode-selecting principle of a F-P interferometer and experiments of mode selection and mode-locking of a laser diode with an external F-P interferometric cavity are demonstrated and reported for the first time. The septic and dynamic single internal-mode operation is realized by using a PZT to adjust the interval of the F-P interferometer.The nearly transform-limited Gaussian pulses with a repetition rate of 656 MHz and pulse width of 13 ps have been obtained. The time-bandwidth product is 0.46. At last the effect of a F-P interferometer on the lasing mode of diode lasers is discussed.

Within the frame of the mean field,using Lorentzian functions to model the gain and spontaneous emission,implicit analytical solutions to the mutli-mode rate equations, including the contributions of spontaneous emission to various diode modes, have been obtained. As a result,with the emphasis on the threshold region,several laser characteristics of importance,such as the carrier density, photon density,etc.have been investigated theoretically and experimentally.

Using a Ti:Sapphire rod grown in China a Single-transverse-mode CW laser has been demonstrated with an astimagition compensated fold cavity of four mirrors.The pumping source was an argon laser with all lines output. With three sets of cavity mirrors the tuning ranges were 680～760 um,730～ 840 um, and 970～1010 um respectively,while the peak power wavelength was 780 um.Up to 2.35W of output power and 33. 49% of slope efficiency were obtained with an output transmissivity of 11.76% at 780 um for a pump power of 10.0 W.

Using a disturbance develop method, we have obtained the formula for the small signal gain (S. S. G.) of the variable parameter Smith-Purcell effect FEL and show that the gain spectrum function factor takes the same form as the variable parameter Wiggler.On the basis of this formuls, the S.S.G. for linerly varying of grating space frequency is discussed. The resultS show that when the speed of the injected electron is within a range,lower than the initial resonance speed,a higher S.S.G. can be attained, and that in order to enhance S. S. G. for a given saturation efficiency, the changing rate of grating space frequency should be chosen properly.

In this paper,the parameters of a Ti: sapphire laser and their correlation have been studied bssed on the Gaussian theory.The nonlinear effect of Kerr lens has been considered for the first time.According to the theoretical results a laser resonator was designed for our experiment,from which emitting of the fundamental mode with a maximum output energy of 77.3 mJ,tuning range of 650～1039 um and the divergence of about 1 mrad have been obtained.

A simple expression deduced from EDFA (Erbium-Doped Fiber Amplifier) rate equations and light propagation equations is presented in this paper.Using the expression,gain and NF(Noise Figure) of amplifiers can be calculated.The simulated calculations are in good agreement with experimental results before the amplifiers are saturated.

Optical third-harmonic generation in Cesium medal vapor is discussed in this paper.The theoretical analysis shows that there is a two-photon resonance enhancement effect for nonlinear susceptibility Ｘ(3)(3ω)of Cesium at wavelength 1.0790 μm.The temperature which is necessary to achieve phase matching is given. It's the first time that the third-harmonic spectral line(359.7 μｍ) of the fundamental wave 1.0790 μm in Cesium vapor is photographed experimentally.

It has been proved that the TEM00 beam has the minimum propagation factor M2. The specificities of the propagation factor M2 of the Multi-modes laser beam, partially coherent beam and wave-front distorted beam are discussed and compered.