In this paper we report a general system for measuring wavelengths of lagers, both CW lasers and pulse lasers. The system consists of a grating spectrometer and a one-dimension optical multichannel analyser. We use a low-density grating and operate in high-order diffraction. The distance between the He-Ne laser line and the laser line to be measured on the output spectral plane is read out in real time by the array of the OMA, the laser wavelength is then calculated by a personal computer with an error of 0.001 nm An analysis on the error is presented.

Triangle interferometer is the simplest ring-type interferometer. Its advantages include roughly equal optical path, high measuring accuracy and continuous shearing amount. However, its nature of shearing interference brings about complexity in quantitative investigations. If a Ronchi grating is placed in front of the triangle interferometer, optical beam is diffracted. The zero-order andiffracted beam and first-order diffracted beam are taken as the object beam and reference beam, respectively. They are combined to form interference fringes in the triangle interferometer. In this way, characteristics as a triangle interferometer remain, while lu terference between same points on the wavefront is realized, thus making data processing much easier, Sinee the two beams are very near to each other, they are able to transmit fchroagii the same optical component so that the optical system becomes simple and easily adjustable, A grating-triangle interferometer is fully competent in obtaining interferograms of laser plasmas which require a time resolution up to lops. Homogeneity of refractive index and thickness of ordinary transparent media can also be measured with a grating-triangle interferometer. Interferograms of laser plasmas and Nd-glass laser rods have been obtained by using ihis interferometer.

The high sensitivity of a ring laser is used for measuring Verdet constants V of Tb glass and ZF2 glass in a weak field. The measurement results show that the value of V in a weak field coincides with that in a strong field. Based on the results, possible applications in sensing the earth magnetic field by placing Faraday magneto-optics glass in a ring laser are discussed.

The operating characteristics of a hybrid TEA CO2 laser are analysed based on a numerical model. We have found the possibility of single longitudinal mode oscillation in a low-pressure CW CO2 tube operating below the lasing threshold. The results have been borne out by experiments.

The general expressions for the retroreflective power coupling coefficients of a fiber coupled with a reflector have been derived for propagation of both incoherent light and a laser beam Gaussian beam. Furthermore, expressions of retroreflective power coupling coefficients for several different reflectors coupled with the fiber and when the reflector is moved along the axis of the fiber-reflector system are also shown. Curves of the retroreflective power coupling coefficients for both fiber-plane mirror and fiber cat's eye refleotor systems have been measured experimentally.

Optimized parameters of the optical configuration of holographic wavelength demultiplexer (HWD) have been obtained with aberration balancing. The wavefront aberration caused by wavelength shift has been minimized. The image size of a point source formed by HWD was determined by ray tracing. To reduce the size of the image, we propose a phase compensation function to calculate the image size. The phase compensation could be achieved by Computer-Generated Hologram (CGH).

The calculation of theoretical "screen effect " from the viewpoint of mutual matching of spectral tristimulus values of a CIE standard colorimetric observer with color negative films and color printing papers is described in this article. The corresponding peak value position, half band-width and peak value s allowance of Red, Green and Blue of color measurements of color negative films are provided. The metamerism analysis and error analysis for the color measurements of general wavelength values are given. The experimental results have boi'ne ont the analysis. Each peak value comforms to the data published by Kodak Co. and French Co., and is nearly equal to the data pxoyided by a foreign color printer. Our data will provide reference for workers engaged in color photography and research and design of photographic equipment.

HEMG (High-Efficiency Multi-beam Gratings) are widely used in optical systems as splitters. HEMG should have (1) high diffraction efficiency and (2) uniform intensities at each diffraction order. High efficiency is realized by making the phase grating. Uniform intensities may be attained by either W. H. Lee s PPM Pulse Position Modulation) or PWM (Pulse Width Modulation). However, when the number of the required uniform beams increases, or when we deal with certain kinds of 2-D HEMG, these two modulation methods will lose their effectiveness, and become either ???perfect or too complicated to be practical. In this paper, we introduce the iterative method to design HEMG. Some practical results are shown.

The dependence of thermo-optic coefficients W of glasses on temperature and wavelength has been investigated. The results show that W increases linearly with temperature according to the equation Wλt = Wλo+θt, while it decreases which increasing wavelength according to the equation W2 = A0 + A1λ2 + A2λ2+A3λ-4+ …. It has been found that thermo-optic coefficients W of glasses at any temperature in the range from room temperature to annealing temperature and at any wavelength in the visible region can be calculated by these equations.

Reported here is a theoretical treatment of double degenerate forward coherent multiphoton scattering in a nonlinear medium. Both direct-coupled and cascade-coupled precesses are obtained. In a dye cell the forward coherent multiphoton scattering up to the 15th-order was observed in our experiment. The theory agrees well with the experiment results.

Due to the motion of light source, one well known difficulty in fast-beam spectroscopy is the large line width caused by the Doppler shift of light across the collecting optics when a spectrometer is coupled to the beam in a conventional manner. In order to study the high-resolution beam foil spectroscopy of an 800-keV He+-ion beam passing through a transverse magnetic field, an off-axis Fabry-Perot interferometer was used and a line width of about 0.2 A was observed. The principle of coupling a fast beam to the off-axis Fabry-Perot to obtain Doppler compasation is described along with experimental results.

A systematic method for calculating spectral term energies of the fN configurations with the Young-tableau form wavefunctions is given. Expressions of matrix elements of Young tableau bases and calculating rules are presented.

The vibrational levels of some low-lying electronic states of diatomic SnO and the Yibrational bands that arise from transitions between such levels have been calculated by using algebraic techniques. The results thus obtained are in agreement with experiments and the results of classical analysis.

The phase dispersion effect of intercavity elements plays an important role in the femto-second technique. This paper describes an experimental method for measuring the phase dispersion of multi-layer wide band high reflective dielectric coatings by means of multi-beam interference. The phase second derivative of reflective coatings is calculated. Experimental results show that the phase shift and the phase second derivative are closely related to the manufacturing process and design of the wide band multi-layer reflective coating.

When multi-layer thin film reflectors and beamsplitters are used in diffraction-limited imaging systems (such as a mask projection aligner) and in precise interferometers, where elements mentioned above are used in cone beams, special attention should be paid to the phase distortion and dispertion induced by these elements. Reflective phase distributions of some specific films are calculated by using the well-known characteristic matrix method. It is explicated that an element of this kind acts as as a phase distortion element with respect to the incident angle and as a phase dispersion element with respect to wavelength. For a 71-layor UV wideband reflector，the phase distortion and dispersion can reach 3; for a 31-layer neutral reflector, 0.78; for a 6-layer prism beamsplitter, 0.2. Moasuromont of phase distortions bj means of polarization holographic interferometry is described in details in this paper. Information about tho phase distortion of a whole wayefront can be obtained directly. At the end of this paper, it is pointed out that the experiruental results agree well with, numerical analysis.

This paper describes the principle and technology of the preparation of soft X-ray filters. Experimental results are presented. In particular, we compare the performance of Al-Mg alloy film filters with that of Al film filters. It has been found that Al-Mg alloy film filters are better than Al film filters in the capability of resisting damages caused by rocket launching.