The motion track of relativistic electrons in a spatially periodic transverse magnetic field has been analysed. Under some conditions, the electron motion is harmonic in the direction perpendicular to the original incident one. Radiation spectrum and spectral width have been obtained using harmonic mode, nonhamonie is also discussed. It has been shown that radiation spectrum depends on the initial electron velocity and the intensity of magnetic tiell.

Theory of Fresnel scale diffraction and imaging rule of optical mode were used to investigate the resonator with internal lens and basic structures of equivalent resonator are introduced. Calculation and analysis show that a parallel-plane resonator with internal lens may be equivalent to the plane-spheric resonator. l.t is a thermally stable resonator if the alignment of the nsonator mirrors and lens satisfies the formulas derived in this paper. Properties of mode selection of this type of resonator and some design examples are discussed too.

It is proved that the employment of two-fold or four-fold speed-up deviee is necessary for a shutter Q-switch and there is a slight flicker of the laser beam in the cavity. The mechanism of multi-pul ses generation is explained. The numerical calculation for typical cases is completed with a computer. It is proved that the performance of the shutter Q-switch will be improved by placing- the prism in a closed cell with gas of suitable refractive index.

In this paper, we describe a 200Mb/s modulation experiment employing an injection GaAs-GaAlAs DH laser.The modulation is driven by the bias current below the threshold.

Improvement of the pumping performance of flashlamps used in dye laser excitation with intense pulse preionization as well as the optimum conditions for operation are studied. A simple and reliable circuit has been developed and the laser efficiency has been doubled.

At present, plane parallel resonator is often used in multipulse laser drilling with average distribution of pulse energy. We consider it is disadvantageous in regard to accuracy, surface finishing and reproducibility for the drilled holes. Through analysis and experiments on output characteristics of resonators as well as rational distribition of pulse, energy, improvement in accuracy, surface finishing and repoducibility of the .drilled holes can be achieved, especially in improving their taper, by using false concentric resonator with changeable energy.

Selection of laser pulse shape, pulse duration, flux density are discussed in pulsed laser microwelding and the experimental results are given.

In pulsed flashlamps and filter envelopes made of quartz tubes with appropriate thickness and proper concentration of doped rare-earth elements, such as cerium, europium etc, UV radiation below 3500 A is essentially eliminated, thus filter solution and yellow glass filter envelopes in solid state lasers can be replaced and the colouring of laser material prevented.Comparison has been made among filtering characteristics of different filter materials and their efficiencies in repetitive pulse Nd:YAG lasers. Experimental results show that using doped-quartz in Nd:YAG laser and Nd:glass lasers, laser efficiency can be increased by (25-100)%, or even higher.

Three types of loss factors-surface scattering, volume scattering and absorptance for optical thin films have been systematically analysed and calculated. The reflectivity, transmissitivity and losses of the optical thin /Jims were calculated with these factors existing simultaneonsly. In computing program, the effects of various loss factors on optical properties of thin films have been taken into account, so the computed model and ways are more universal than the ordinary ones. As examples the computed results for eleven layers of ZnS/MgF2 reflective coating and twenty-one layers of TiO2/SiO2 reflective coating are given.

This paper describes a mixed dielectric waveguide laser glued by polished quarts plates and polished copper plates, with cross section of 1mm×1mm. Preliminary results on CO2 laser output from multiple transverse synchronous discharge in waveguide filled with He, N2 and CO2 gas mixtures are reported.

In the experiments on laser heating of plasma, angular distribution of laser beam energy is measured by array imaging. In combination with the principles of equivalent planes, the time-integrated energy distribution was meaured at the focal plane and various planes out of focus of target lens.