This paper presents a novel method for evaluating the resolution of a plane diffraction grating. The phase of wavef ront diffracted oy a grating under test is measured with interferometry and a graph of 3D)-shape of the diffracted wavef ront is obtained. The the Fourier transform is carried out by the algorithm of FFT and the intensity distribution in spectral diffraction pattern and the half width of the spectral image are determined. The advantages, fundamental principle and the experimental technique of this novel method are described, the results of experiments and computation are presented too. They are in good agreement with the resul obtained by the method commonly used.

Phase retrieval problem is one of the most important projects in modern optics. Among many iterative methods, Fienup algorithm had made a great success. In present paper we describe a new method which has been demonstrated to be more practical than Fienup algorithm, by which an original object oan be reconstructed from a single intensity measurement-the modulus of Fourier-transform. Precisely like Fienup algorithm, tha new algorithm is still an iterative Fourier-transform method, however, the con ergency of the new method is much faster than that of the previous method. The two-star model is adopted as the example of object function, and the calculation results obtained by using two different algoritiuns have bean compared in detail.

A simple and useful new method of measuring the absolute fluorescence quantum efficiencies of laser dyes by thermal lens effection is described in this paper. Using this method, we measure the absolute fluorescence efficiencies of oxazine 1 perchlorate (Ti njin Dye Institute, China) which is dissolved in several different solvents and different conoentra-tions, and discuss the unusual phenomenon, i.e. when the dye is dissolved in the 1, 2-dichloroethane or trichlotome-thane, it has much greater quantum efficiency than in the ethanol absolute, water etc. Wethink, retraining the vibrations between atoms of chromophore will be a effective way to imporve the absolute fluoresoence quantum efficiencies of 1aser dyes.

A new method for measuring single-mode wayeguide parameters is presented in this paper. Mode refractive indices of fundamental guided and leaky modes at two polarization states are measured lay the prism coupler, and single-mode waveguide parameters are determined from four corresponding mode equations. Its measuring accuracy is higher than that of measurements of pure guided modes. Single-mode glass waveguide parameters were measured toy this method, and its error sources were analysed theoretically.

The eigenfuctions and eigenvalues of a cascade three-level atcm irradiated by two light fields are derived. The formulae for evolution of the atom are obtained. The changes of the populations of atomic levels and of the polarisation of the atom with respect to atomic levels and of the polarization of the atom with respect to the intensities of the fields are studied. The influence of the phases of fields and the atomic wavefunction on the dynamics of the atom is discussed. When a relative phase is equal to π the interaction between the atom and the fields reachies a minimun. In certain circumstances the minimun may be zero, which indicates no coupling between them.

Relaxation Oecillation of the light intensity in the rare gas halide excimar medium is described. The high-pressure mixture consists of rare gas, halogen and appropriate buffer gas. An argon laser-beam was employed to probe the active medium. We derived a differential equation describing the change of the photon density with a perturbation method. The relaxation oscillation period calculated is in agreement with the experimental value.

Making use of the result given in the previous paper, this paper inyestigatefl the influence of intensity and detuning of the pump field on squeezing and gives the numerical calculated result.

A concept of TV-signal to noise ratio transfer function (SNTF) is proposed in paper, and a deterotive equation is established based on the SNTF. Theoretical calculated resulte well coordinate with the experimental results. Values of detectivity of LLL-CCD cameras under several different conditions are calculated based on the equation with the aid of computer. After analysis of the results, some ways of improving detective ability of LLL-CCD are proposed.

In this paper, an improved Beheim mathod is described, by which the stability of the intensity modulation optical fiber sensor can be enhanced in the measurement of many physical quantities, the experimental results for measurement of relative disp acement are given.

This paper reports the principle and the experimenlal vesults of the ring laser magnetic sensor for weak field (RLMS) for the first time. Theoretical analysis indicates that the ELMS suseceptibility mainly depends on the merit coeffecient of magneto-optical material. In our experiments a terbium-silicate glass of 20 mm length is used as a Faraday cell, a susceptibility of 2.9 ×10~(-8) Oe/Hz (0.0023A/m·Hz) and a random shift of less than 2.3Hz during 9 hour have been obtained.

The homogeneously doped single crystal of ErxY1-xAl3 (603)4 in centimeter order was grown with flux mathod. The absorption and excitation spectra were measured. The oscillator gtrengths of eleven trasition bands and intensity parameters of Er ion were calculated by Jndd-Ofelt theory. From these results the Einstain spontaneous radiative emission cross-sections of different transitions were obtained. With these parameters the possible lasing transitions in EYAS crystal are discussed.

The fluorescence spectra of four Rydberg series of Ybl have been obtained using laser stepwise excitation in atomic beam. The new energy level data of 6m S1 (n=15 to n=22) and 6s23s 1S0, 6s24s 1S0 are first reported.

Dispersion produced by turning a multilayer thin film Gires-Tonrnois (G-T) Interferometer is accurately calculated with the aid of computer. Experimental Investigation has been carried out. This device can provide adjustable dispersion by turning the angle of G-T interferometer. A G-T interferometer with suitable construction parameters ean be used as a cavity mirror to compensate upchirp in the cavity in order to get shorter optical pnlses.

The optical properties of amorphous In-Sb films have teen measured. The formulae for transmission and refleciion coefficients for two layer films with regard to the interference effect are deduced and used to analyse the measured data. The n-λ, k-λrelations of In-Sb films have been obtained, and from them the optical gap and the dielectric constant have been calculated. The change of optical gap due to phase transition are discussed.