In order to maintain the constant gain coefficient and invariable phace difference between pumping field and radiation field of a free electron laser, we use a variable spaeial period length g which decreases gradually along the transmitting direction of relativistic electrons in the weggler. Thus the energy conversion efficiency of free electron laser can be raised. The equation for g of the resonator different from that of an amplifier of free electron laser is also given.

Self-consistent equations for traveling-wave Gaussian beams (TEMoo) and their third-order solutions are given and extended to obtain output expressions of four-frequency ring lasers when axial and radial distributions of beams and a series of parameters are considered, so that the theoretical basis is provided for better understanding of the distributions of Gaussian beams and parameters as well as their relative about effects, on beat output, positions.

The design and the performances of a CO2 laser power stabilization loop are described. Using a CO2 laser stabilized by saturated absorption of fluoresence as frequency standard while the power stabilization loop was open or close we measured laser frequency stability.The results show that it is possible to get a tunable CO2 laser of stable frequency and power using a power stabilization loop.

This paper presents the results on coupling power and plasma characteristic impedance of XeCl excimer lasers by measuring the discharge voltage and current. Influence of function form of the characteristic impedance on discharge process and classification of discharge stability are analyzed and problems are discussed.

This paper describes the influence of the optical inhomogeneity of a nonlinear crystal on the frequency doubling for transversely homogeneous beams. Using coupled wave equations,the analytic expressions for the longitudinal optical inhomogeneity of a nonlinear crystal and the frequency doubling efficiency, and the approximate formula for determining the optimum crystal length have been found. The influences of longitudinal and transverse optical inhomogeneities on the frequency doubling have been compared.

The resolution limit of Hg and Na yellow doublets is studied theoretically and experimentally by holographic method. The intensity distribution of the above spectra is calculated and measured. Several characteristics of the infinite resolution and the measurement of the wavelength under this condition are discussed.

SES of liquid air was pumped by a ruby laser using dye for Q-switching. The obtained SES spectrum consists of 13 lines from 0.5247μm to 1.0256μm.

A unique vortex gas flow stabilized flashlamp has been developed for dye laser pumping. With a 3μs current pulse the flashlamp can operate at up to 100J/pulse and a pulse repetition rate of up to 100 pulse/sec. An average input electric power of 10kW and a maximum electro-optic conversion efficiency of 35% have been achieved.

This paper discusses mainly the primary principle of IT/E method, its contrast ratio, resolution, magnification and emissive pattern, and the factors relating to the applicable sphere, more information about the experimental method and results are presented.

This paper presents the features of a lens designed for converging the laser beam onto the target and the solution of the aspherical lenses using equal optical path principle.

We have investigated the features of the aperture smoothing factor under the condition of non-homogeneous turbulence. The results are quite different from those obtained from homogeneous conditions. It has been shown that in order to get a good smoothing effect the reciever aperture of the laser engineering systems should be at least one meter.

The principle and structure of an accurate thermostat for temperature control of optical elements are reported. By means of auto-compensation, the zero drift in the width-modulator, high accuracy thermostatical effect is obtained.

Described in this paper is the selection of optimum parameters for model WJX-I laser microspeetrometer.

Cooling rate being an important parameter for laser annealing is estimated approximately to be proportional to τ-3/2(Tindicates the pulse duration)under the condition of constant input energy. When rgoes from 25 ns to 25 ps, however, the cooling rate increases only by about an order of magnitude by our calculation.

Free radical films have high resolution and sensitivity. Studies of the filmsin recent years and some of their applications are reported.

The aecidiospores of the blister rust fungi of Korean pine were irradiated by laser to see the killing effect and the results are reported.The matured spores were irradiated with CO2 laser of 10.6μm with a power density of 5w/ cm2. 92.14% and 90.66% of the aecidiospores were killed when the spores were irradiated directly 19 seconds and 2 seconds respectively.

The effects of He-Ne laser radiation on the red blood cell membrane of rats are studied. The results obtained by measuring the cell-electrophoresis, hemolysis and morphological change etc. show that the damage is detectable after exposing the cell to laser light for longer time.