Using hollow cathode lamps, the atomic state lifetimes have been measured by laser fluorescence spectroscopy. The results coincide with the data obtained by other methods. This technique has proved its simplicity and versatility compared with others.

An experimental investigation of the optogalvanio effect of ArII in an HOD lamp by using an Ar+ laser, with its Ising line at 514.5nm, 496.5nm, and 476.5nm separately is reported. By considering various effects, such as ionization, recombination, and other mechanism of excited ions, we propose a simplified model which can be used to explain experimental results satisfactorily. The possibility of measuring some parameters of discharge plasmas in low-possibility of measuring optogalvanio effect is also suggested.

In this paper a convolution form of atomic spectral profiles having isotope shifts transformed by a scanning planar Fabry-Perot interferometer (SFPI) is presented. The method and corresponding code of deoonvolution of the spectral line profile obtained by SFPI are proposed and are characterized by using the nine-parameter Gauss iteration of the least squares fitting for the first time. By this method the magnitude of isotope shift, isotope abundance ratio, Lorentz width and Doppler width of the spectral profile can be deduced.

Synchronized by being triggered with the same spark gap, two independently tunable flashlamp-pumped dye lasers with compound cavity structure were used to obtain saturated doubly resonant (3S-3P-4D) three-photon ionization of sodium. Eate equations of such a system under the condition of saturated transitions were analytically solved. Comparison of the calculated ionization curve with experimental results gave good correspondence. The ionization cross section of sodium 4D state has been measured from the cuarve at laser wavelength 689.0 nm σ_(4D)=(589.0 nm)=(1.2士0.4)×10—18 cm2. It is in good agreement with, the theoretical calculation, which is also given in this article.

It is necessary to compensate the dispersion completely within the demanded wavelength range in a mode-locked laser cavity for obtaining ultra-short pulses. Operation with no dispersion can be achieved by appropriated design of films coated on mirrors to match the medium inside the cavity. In this way, ultra-pulses can be obtained.

Based on the injection carrier diffusion equation, dynamic characteristics of the crescent GaAs/(GaAl)As lasers integrated with buried passive waveguide have been analysed by using Eunge-Kutta and Simpson numerical method. Effects of structure parameters (such as central thickness do of the active layer, stripe width S, channel width W, and carrier diffusion length LD) on the threshold current Ith or threshold current density Jth are analysed. According to the analysis, in order to reduce the threshold current or threshold density, the ohanriel width W must be reduced to 2~4 μm and the stripe width S must be less than 5 μm. A cavity length L=350 and a thickness d0=0.17 μm are reasonably recoromended. Centers of non-radiative recombination should be reduced, the more the better. In this way, optimum results can be reached. We also discuss the way to improve device quality and device structure in this paper.

Theoretical and experimental results of the intensity profile modification of a Gaussian laser beam by 2-D ultrasonic standing waves are reported. The results indicate that the Gaussian intensity profile of a focused laser beam can be modified by a 2-D ultrasonic standing wave when the spot size of the Gaussian laser beam on the input face of the acoustic cell is small than the ultrasonic wavelength. The intensity of a focused laser beam can be made nearly flat in the central region if the acoustic pressure properly controlled. The flatness and the flat region can be changed continuously by varying the acoustic pressure.

The principle of non-contact photolithography for reducing the diffraction effect is analyzed systematically in terms of the diffraction theory,and solutions to constructional parameters of optical system for reducing the diffraction effect have been obtained. The relationship among different widths of lines as well as clearances is presented, and it has been proved by a lot of experiments. The new type of optical system has been used in a circular dividing machine, which is useful in obtaining high-quality gratings.

In this paper, the relationship between characteristic of surface roughness and average contrast of laser speckle pattern has been derived directly from the Fresenel-Kirchhoff diffraction formula by means of light intensity distribution. Two forms of autocorrelation function have been considered, and the corresponding results are very similar. The method of measuring surface roughness using average contrast of laser speckle pattern can be used in measuring roughness of precise surfaces with high accuracy and high resolving power.

This paper is about the experimental measurement of stray light in Raman spectrometers and the related difficulties. It is necessary to attenuate the intensity of incident light for studying the stray light distribution in a Raman spectrometer. By using optical absorptive liquid, the intensity of incident light can be attenuated conveniently while the condition of optical match still maintained. It is simple to measure the light intensity change of the order of 1013 if the method of attenuating light intensity Is used. A new experimental scheme for measuring stray light in Raman spectrometers has been suggested. The results of experiments are given for SD-II and SD-IV holographio concave grating monoohromators and doublemonoohro-mators. Finally, it is suggested that the stray light test conditions should be unified.

The photon statistic of two-photon processes is treated for the general case of two-level systems. After generalizing the generating-function method, we derived the generating function with parameter r (atomic population ratio), its partial differential equation, and equations of factoril moments as well as equations of correlation functions. Analytical solutions were obtained for various values of r. Curves of and g(2) versus τ and r were deduced for three kinds of initial fields. Both the effect of r on photon antibunohing and characteristics photon statistics for two-photon amplifiers are discussed. The photon super bunching is proposed as one of tJie criteria for two-photon amplification.

A kind of enciroled-circular double wedge (E-CDW), in which shearing amount could be varied continually, is recommended for speckle shearing interferometry. A "shearing vector" is introduced to analyse the related principle. Experimental (results show that the quality of fringe patterns at the border of viewing field can be improved considerably.

Transfer characteristics of the whole forming procedure of phase encoding gratings by bleaching silver halide films are briefly described. Different structures of encoding phase gratings are presented. We have also calculated chromatioity curves which depend on the specific structure of the phase grating and the color temperature of the source used. The nonlinear effects of the film on the phase modulation depth and encoding results are also analysed.

We have studied the mechanism of the anisotropic property of degenerate four-wave mixing (DFWM) signal intensity in nematic liquid crystal doped with dye. Such property originates from two sources. One of them is due to the anisotropic absorption of dye molecules. The other is due to the optical birefringence of liquid crystal in its nematic phase.

Stability ef electron trajectories in free-electron lasers with an axial magnetic field is analysed in this paper. The results show that in the case of non-cyclotron-resonance( ),the trajectories are instable if the condition( )/(2ww)2= 1 is satisfied, while in the case of cyclotron-resonance ( ), the trajectories are always stable if the initial perpendicular velocities of electrons are small. On the other hand, oscillation amplitudes of the parallel velocities of electrons depend on the ratio Bw/B0. The smaller the ratio, the smaller the oscillation amplitudes.

We developed a new technique using a phase grating, which modulates the near field of a laser beam to form a far-field flat-top intensity profile. The conversion efficiency is about 90%.

The laser excitation fluorescence spectra of CaOH A-X(100)-(000) transitions were investigated. The assignments were made, and the molecular constants of A2II1/2(100) state were derived by least-squares fitting to be B =0.337097 (10), D = 0.877(5)×10-6, and P=-0.04039(2)cm-1. The rotational temperature of CaOH was also derived from the relative intensities of the rotational lines to be TR=308K.