Propagation, properties of solitons in a transverse segmentally continuous medium (for example, an elliptical-core single-mode step-index fiber) are analysed by considering both the nonlinear effect and dispersion effect. Fiber configurations and effects of the soliton amplitude on polarization dispersion and soliton wave-width are discussed. Theoretical calculations show that the polarization dispersion reaches zero at a specific amplitude of the soliton.

According to features of integral sampling in optics, a concept of sampled point spread sequence is introduced,which makes the system isoplanatic in the discrete sense. In addition, double space filter actions of the element aperture are discussed. A basic theoretical model for the image transfer characteristics of mosaic area array has been developed. This paper also presented a new method, which can be used for evaluating image transfer performances of the system.

One of the auccessfull applications of computer holography is the testing of aspherie surfaces.Computer generated holograms (CGH s) provide an ideal reference wavefront for the test. Thig paper describes briefly the principle and experiment of the testing of aspherics with compensating method using computer-generated interferograms (CGI), and proposes a testing system that does not introduce additional aberration. We used the CGI as a compensating plate and inspected the surface according to Moire fringes. The relation between the aspheric surface figure and the intensiisy distribution of Moire fringes is analysed and simulated on a computer. Various factors that could possibly affect the test precision are discussed. The set-up used is very simple and convenient to adjust.

In this paper coherent excitation of two-photon resonance in three-level systems is discussed. Under the condition of two ultrashort pulses with the same waveform, analytical solution of Blochequations of two-photon resonance, level-population and expression of excitation rate in three-level systems have been derived. Conditions for full inversion of population and maximal excitation rate have been obtained. With average-field approximation, analytical solutions of Bloch equations of two-photon off-resonance have been obtained. The analytical expression of isotope coherent selective excitation coefficient has been deduced* Theoretical calculaiiioiis show that the coherent excitation of two-photon resonance has a very high Isotopic selectivity.

Study on the mechanism of Ne 1s2-2p anomalous POGS in HCD was carried out by measuring two-step excited POGS and LIP signals simultaneously. Theoretical analysis is also presented in this paper.

The concentration quenching of fluorescence and Nd3+ ion-ion interaction in NdxY1-xPO4 crystals were investigated by laser-excited time-resolved site-selective spectroscopy techniques. Results showed that the concentration quenching in such crystal is stronger than that in NdxY1-xPO4, and the quenching rate has a linear dependence on x2. The time-resolved site-selective spectra suggested that the Nd3+ iona occupy a variety of nonequivalent crystal-field sites in Nd0.03Y0.97PO4. From the dependence of site-selective spectra on time and temperature, it is believed that energy transfers between Nd3+ ions in nonequivalent crystal-field sites occur via two-phonon-assisted processes with, a resonant energy of 117 cm-1, an energy transfer rate ωs=2.7×104 s-1, a room-temperature diffusion coefficient D300 K=2.15×10-9 cm2 s-1, and a room-temperatisre diffusion length L300 K= 14.4×10-7 cm.

Cavity configuration of a colliding pulse mode-looked Nd: YAG laser is reported. Stable mode-locked pulse trains were observed on a 500 MHz oscilloscope and the average pulse duration was measured to be 10ps. The relation between dye concentration and threshold of mode-locking was studied in detail. It was found that mode-locked multi-pulses would appear when the pump energy was increased.

Stimulated peak cross sections and quantum efficiencies of Er3+ ions in glasses wore calculated and pumping characteristics of Er3+ ions are discussed. The potential of obtaining laser action in Er3+-glasses at room temperature is estimated with the suitable host glass for laser transition identified.

Raman spectra in K2H(IO3)2Cl crystals grown from aqueous solution at room temperature are reported. There are some spectral lines with very high Raman scattering efficiencies. This suggests that the crystal might be a good material as raman frequency shifter. The characteristic vibrational frequency of hydrogen bond (O-H-O) exhibits in the Raman spectra. Spectral patterns corresponding to the same representation A1(TO+LO) but obtained under different 90?scattering configurations y(xx)z and z(yy)x are obviously different. This kind of crystals is found to be vulnerable to damage by light.

A new formalism of the squeeze operator has been found by integration within normal ordered products. Based on this formalism, the essence of the formation of the squeezed state can be revealed directly and clearly. Various representations and properties of the squeezed state can be derived easily. It has been proved that the squeezed state is a coherent one in the quasiparticle space. The transformation relationship between squeezed states and eigenstates of both coordinate and momentum operators are presented. Also presented is the Wigner distribution function of the Squeezed state.

Experimental results on transient rf optogalvanic effect of Ne at low pressure are presented. Since there is no cathode in a rf discharge, the cathode effects are eliminated, Absorption and fluorescence spectra of the sample obtained simultaneously on such apparatus illustrate that the direct photoionization by high-energy photons plays an important role in the optogalvanic effect.

Primary photoelectrons were produced on a solid surface by radiation of a tunable double-frequency dye laser. Pulse-height spectra of the primary photoelectrons in the proportional counter are measured on a multichannel analyzer. A simple exponential-decay pulse-height spectra of single photoelectron was obtained when the laser intensity was made very low. In this way single photoelectron on solid surface was detected.

The third-order succeptibility of recombination-type semiinsulating gallium arsenide was measured to be 8.3×10-7esu with a multi-kW CW CO2 laser. The value is in good agreement with the result calculated from the impurity energy levels of this material.

A brief account of the principle of multiple-pass Raman gain cells (MPC) is presented. A simplified method has been adopted to measure reflectivities of mirrors of the resonator. The optimum transit number was determined to be 20.

Taking radial and axial inhomogeneity of medium into consideration, we have obtained augmented transfer matrices and flow graph structures. As their applications we have studied the effect of air index gradient on laser alignment and the additional diffraction loss of laser caused by inhomogeneous pump. Results show that the axial index gradient can compensate the effect caused by radial index gradient in some cases.