An equivalent variable aperture method for mode field radius measurement of aingle mode fibers is proposed. It involves measurement of the integrated far-field distribution with a circular aperture moved axially in the far-field of the fiber. In sddition, calculation method of the mode field radius, which is also suitable for non-Gaussian field dis-tributions, is derived by using Petermann s new definition of mode field radius. Experiments have shown that this method is simple and reliable. The typical deviation of repeted measurements of the mode field radius of a given fiber with, different ends is less than 0.04μm.

The Talbot and Lau effects of Ronchi gratings are treated by the ambiguity function in this paper. Furthermore, both effects are developed is fit any optical systems. Because of quasi-ray-optical operation of the AF, two general formulas directly describing the patterns of the Talbot and Lau fringes respectively are derived in a quite simple form. All the variables in the formulas depend only on the transfer matrices of the optical system used. The Talbot and Lau effects of complex gratings are also discussed.

Cylindrical lenses have been widely used in moder optics, but there is still no satisfactory technique for their testing. The methods available at present all have some drawbacks more or less. In this paper we present a new method for testing a cylindrical lens by using holographic interferometry. The principle of the method is discussed and the experimental results are given, also discussed is a method for adjusting the relative position between the slit and cylindrical lens. This method has several advantages, such as simple structure, easy operation and decrease in the requirement on optical elements. Therefore, this method can. be used in routine test of cylindrical lenses.

This paper discusses the application of HOE in optical measurement of high temperature and gives primary experimental results.

The effects of gas mixture ratio, gas passivation, optical window deposition and laser gas storage time on the lifetime of a transverse flow XeCl excimer laser were studied in detail. By optimizing these parameters, a lifetime of more than 105 pulses was obtained with a storage time of 1000 hours for one gas fill.

The Hamiltonian and equation of motion for the order parameter of a single-mode standing-wave laser system with saturable absorber are given in detail. Three stationary solutions of the equation are obtained near the threshold; their stability is analysed. The results show that the stationary behavior (nonequilibrium phase transition, bistability, critical exponents) of standing wave system near the threshold is similar to the of a traveling wave system qualitatively, but they differ quantitatively. Among she diffefences, it is worth to emphasize that it is possible to realize I-(one of the three stationary solutions) branch experimentally, what is not possible in tho travoling-waye case.

Theoretical and experimental studies on waveguide dye spontaneous emission amplifier are reported. Waveguide mode, ASE threold and near-field and far-field distribution are culcalated for a rectangle waveguide model. The output characteristics of the ASE amplifier are experimentally studied. The ASE far-field patterns for the lowest waveguide mode are obtained in agreement with theroy.

The microscopic Hamiltonian of a material, which may be ordered or small disordered, is given. The formulae of refractive index and its temperature coefficient are obtained by using semiclassical method, where the perturbation calcu-lation based on the Hamiltonian is up to third order. From the formulae, the influence of the electron-phonon interaction on the ref active index is studied. It is the first time to point out that the temperature coefficient of refractive index introduced by the electron-phonon interaction (excluded the thermal expansion) is a constant at high tempertnre and is proportional to T3 at low temperature. The contributions of the clectron-phonon interaction and the thermal expansion to the temperature coefficient of the efractive index are positive and negative, respectively. A material with large thermal expansion usually shows a negative tempertur? coefficient, such, as NaCl， while a material with small thermal expansion usually shows positive one, such as ZnSe. The zero dispersion wavelengtli increases with a temperature rise for materials whose thermal expansion can be neglected such as fused quartz. The temperature coefficients of refractive index for some ordered materials and disordered materials have been given according to our theoretical calculation. Theoretical results are compared with experimental data, and a good agrement is obtained.

Electro-optic response properties of a set of HAN cells have been investigated. In particular the transmission variation with applied voltage and the relationship between response time and electrical field have been atudied. The birefringence as a function of applied voltage and turn-on time is worked out. The experimental results are analyzed in terms of the linear-response theory. The results of the response time of the HAN cells are in agreement with the theoretical predictions derived from theory. The results reported point to the possibility of liquid crystal devices with improved response time.

In this paper, the principle of Fourier optics is used in treating the problem of moir6 fringe multiplication formed by two contact gratings. A continuous relationship between displacement and light intensity is obtained. The gratings may be amplitude type, phase type, or amplitude and phase type. Moire fringe multiplication under coherent illumination for both homogeneous and inhomogeneous deformation-field is considered. The resulting formulas have universal significance and agree fairly well with the experimental results obtained by D. Post.

In this paper, using the weighted residual method (WRM), we derive mathematical formulas for calculation of dispersion characteristics and field distributions of guided modes of the strip dielectric waveguides and strip-loaded dielectric waveguides, and formulas for calculation of coupling length of rectangular-core dual channel directional couplers. The derived formulas are simple and easy to use, and the results are more accurate than those of other approximate analysis.

An expression for electron deflection angle caused by Mollenstedt biprism was deduced according to the similarity between electron optics and geometrical optics. A comparison between optical Fresnel and Mollenstedt biprism was given. The effects of partial coherence of electron beam on interference field were pointed out. The obtainable maximum number of interference fringes were discussed.

The luminescence properties of Cr3+ ions in powdered Na2MgAlF7 multicrystal were studied experimentally. The fluorescent emission from 4T2 covers a wide region of 700 nm-1050 nm in the near-infrared. At 77 K, the fluorescence lifetime is about 310μs and the decay curve deviates slightly from single expenential form Temperature quenching occurs at above 200K. Several structures on the spectra are discussed.

It is proposed that there exists principle errors in the shadow Moire topography. The mathematical expression is derived in order to correct such errores. Moire contour photographs are presented. Corrective reckoning of photographs indicates that these formulas are valid.

By using laser narrow line excitation at different wavelengths the linear relationship between excitation energy and fluorescent Stokes shift of Cr3+ in glass could be found. Therefore, the crystalline dynamic field parameters of Or3+ are deduced.

The IR spectra of Li2O-(LiCl)2-B2O3-Al2O3 glasses have been measured and analyzed. Prom this result, we have studied the dependence of coordination numbers of boron atoms and borate groups on glass compositions. The reles of Al3+ and Cl- ions in the glass structure has been analyzed in this paper too.