The design process of contact screens have been investigated. An advanced knowledge of the threshold transmittance is essential for design of reliable screens. Following the theoretical guideline a logarithmic, an exponential and a fidelity contact screen have been designed and fabricated. Experimental results on screen performance are also presented.

A method for making computer generated hologram (CGH) with coding the real or imaginary part of the Fourier transformation spectrum of an object are proposed. The author shows that multiplex technique is applicable to this kind of hologram in the direction of phase coding, therefore one hologram provides many functions. Experimental results are given in this paper.

This paper deals with two types of catadioptric telescope. The first type consists of an aspheric mirror and two thin aspheric correcting plates, which are located in front of the mirror and its focus respectively. The second type consists of a spherical mirror and an aspheric meniscus, which is an equivalent of a spherical Maksutov meniscus with a Schmidt thin aspheric plate. A series of excellent construction for these catadioptric telescopes have been obtained by optimization. Then great numbers of rays tracing results. The image qualities of these catadioptric telescopes are given in the tables and spot diagrams.

Mathematical model of infrared laser heterodyne gas analyser for extracting signal is described in this paper. It is proved that the detecting sensitivity of heterodyne gas analyser can reach up to 10-4ppb, about nine orders of magnitute higher than that of direct detection. The spectrum form of square-wave controlled laser, optical signal heterodyne detecting device and principle of electrical signal demodulation are considered with emphasis. The flow chart of the gas density signal is deduced, according to which the block diagram of controlled CO2 laser heterodyne gas analyser is dxawed.

Comparing the wave-spherical aberrations in practical teat with the patterns of the same lens, the corresponding relations are preliminarily obtained between the quantities of spherical aberrations and the features of diffraction patterns both inside and outside the best focus. Thus, the evaluation of spherical aberrations by star test will be feasible.

The self-focusing, the most important effect on the output power of solid state lasers has been described. High frequenoy spatial modulation induced by Fresnel diffraction accelerates the effect of self-focusing. In order to eliminate the Fresnel diffraction produced by hard aperture, the bandwidth broadening of laser beam for such use is proposed and its effect of diffraction-free has been demonstrated experimently.

A new cavity construction with coaxial-off grating has been proposed on the basis of waveguide cavity theory. An extra-cavity waveguide laser has successfully developed with plane grating of selecting spectral branch. Its behaviour is equivalent to a close cavity with the concave grating. Tuning range of the waveguide laser is from 9.2μ to 10.8μ, and the oscillation at four bands of CO2 has been obtained. More than 57 spectral lines have a power above 0.5 W at a single line. The maximum output power at a single line. The maximum output power at a single line is 2.32 W.

A twin-mesa GaAs-(AlGa) As laser integrated with a passive waveguide is described. It is characterized by amplification with electro-optical injection and mode locking. The laser can be oscillated in a single longitudinal and fundamental transverse mode with a △λ about 1-1.6A by adjusting the synchronous pulse driving currents of both mesas A and B at slightly above threshold. When the ambient temperature is changed abont 1~2℃, a single mode operation can be still obtained.

In this paper an investigation on photo-dissociation mechanism of ethanol solutions of coumarin C311 is presented. The experiments on the-dissociation have been performed by detecting the changes in the absorption, fluorescence, infrared and NMR spectra of dye laser medium before and after the photogradation. It is shown that the photo-dissociation products of ethanol under UV and flash-lamp irradiations are acids. As a result, the following UV laser induced photochemical reaction mechanism is proposed: In UV laser or flash-pumped dye laser, O2 insolvent molecules due to the energy transfer of a dye molecule at a higher excited triplet state T2, are excited resulting in a leuco compound of dye by oxidation.

By solving the coupled power equations of two-mode waveguide, the relations of power attenuation and conversion properties of guided modes to input and output powers from the optical waveguide have been derived. In the glass waveguide formed by ion exchange, holographic grating and glass prism were used as input and output couplers respectively, input and output powers from the optical waveguide were measured, and the power attenuation and conversion coefficients of guided modes have been determined. Experiments show that this measurement method, is simple, effective and specifically applicable to the measurements of short waveguide samples.

The cascade effect produced by polariton in CAES spectra of crystals without center of inversion is discussed. An expression for total third-order susceptibility is derived. CARS and GSRS spectra of LiNbO3 and BNN crystals are measured with the non-collinear polarization configuration at some pumping wavelengths. By filting the experimental results with theoretical expression two-photon absorption coefficients of LiNbO3 crystal are obtained.

In this paper a new approach so-called photolytic silver method is presented for getting a silver-particle phase hologram by bleaching an amplitude hologram into a silver-chloride hologram first and then exposing it to a beam of strong light. Using Tianjin type-I holographic plates, the maximum efficiency of 28 % has been achieved and the hologram is photostable. The fact that the electron microscopic images show that the dimension of photolytic silver particle reaches a limit, of 0.01 μm appears to explain the cause of increasing the diffraction efficiency.

A calculation method is developed for producing an aberration-reduced toroidal holographic grating used in a Seya-Namioka monoohromator. Procedure of determining the proper recording parameters is described. The theoretical results show the availability of the present calculation method.

The dissociation of lower concentration silane diluted with hydrogen has been investigated by OW CO2 laser excitation, and its mechanisan is analysed. The equation of dissociation rate and relationship between the rate and the laser power density is deduced. The experimental results are in accordance with theoritical analysis.

A method of improving laser flux uniformity has been reported. Laser beam passes through a tilted germanium plate which rotates around the beam. The exit beam from the plate will rotate around its axis. In this way, the spatial uniformity of laser flux can be improved. The relation between rotation parameters and spatial distribution of laser flux intensity has been analysed and the experimental results are in agreement with the theoretical calculation.

A measure method for laser mirror scattering in the visible region and its results are described in this paper. The measure errors have been analysed and some of them may be reduced by ±15%, which is cooresponding to ±1.5×10-4(absolute deviation) for the 1×10-3 scattering. The measurement results are easentially in agreement with theoretical calculation and the practice. It shows that the 21-layer λ/4 TiO2-SiO2 hard-film scattering of laser mirrors is generally 5×10-4~2×10-3. The fluctuation of scattering is great, and the mirrors reflectivity is governed by scattering in principle.

Broadband mirrors with two quarterwave stacks superimposed on the same substrat have been analysed. When the refractive indices of films are NH = 2.3 - i5×10-4 and NL=1.46-i1×10-5, two narrow absorption bands are induced in this broad band mirror. The peak value reaches 7%. The causeswhich inducing absorption band are explained in this paper and a broad band mirror with simple construction to reduce the absorption peak at the absorption band is also proposed.