Self-imaging effects are an important mechanism for phase-locking of laser arrays. The self-imaging cavities include the one with phase corrector (Lau cavity) and the other one without phase corrector (Talbot cavity). In this paper, the Talbot cavity is analysed in terms of the Fox-Li treatment. It is shown that the diffractive losses of the in-phase mode and the out-of-phase mode have a cross over point with respect to the cavity interval.

A piecewise linear interpolation solution for obtaining the radial emission coefficient for optically thick, cylindrically symmetric plasma is presented. Two examples are evaluated with the present interpolation and Young's interation. It is shown that the present interpolation is precise and reliable. By using the present interpolation, the generalized Abel equation is separated to a system of linear algebraic equations and the coefficient matrix of the system is an upper triangular matrix, so the present interpolation is very simple to eva luate and easy to master for experimentalists and less computation time is required.

This paper presents the principles and design of large-aperture moire deflector, with high sensitivity and high precision, which uses two methods of real-time holography to make grating for eliminating system errors. With this moire deflector some successful results were obtained including moire defiectograms of shock effect field generated by real rocket exhaust plumes and the multi-directional defiectogram of asymmetric flow, field induced in high ultrasonic speed wind tunnel.

In this paper the electronic structures of the complex ion (CrO4)4- in the crystal Cr:Mg2SiO4 are calculated with the spin-polarizated MS(Xa method the one-electron eignevalues and eigenfunctions and the spin polarization splitting under the symmetry Tand C3v are given. Energies of some optical transitions and the charge transfer transition are calculated based on the transition state theory. The spin orbital coupling constants are calculated with the Case-Karplus charge partition method. The influence of the distance from the ligands on the one-lectron energy levels are discussed. The influence of symmetry changes is also discussed.

The holography and the correlation theory of speckle fields is combined, and a noiograpnic speckle correlation technique is put forward, which is verified experimentaly.

The mathematical formulas of the projection light intensity of a 45?twisted nematio liquid crystal light valve (LCLV) are derived in detail, based on a simplified hydrid field effect mode. With the formulas, we have shown chromaticity diagrams of the pseudocolor under verious directions of LCLV. The chromaticity characteristics of this pseudo-coloring method is discussed, and the optimum rules of LCLV's directions are presented. Finally, the color adjustability and color confusion phenomenon in this pseude-color encoding technique are analysed.

The gain characteristics of the collective free electron laser operating in a superradiant amplifier have been studied through the variation of the interaction length and pumping magnetic field. We could obtain arbitrary interaction length by means of an axially movable "kicker" magnetic field that deflected the electron beam. The experimental results showed that the radiation gain of collective FEL was approximately 1.7th power of the pumping magnetic field with gain ranging from 0.4dB/cm to 1.38dB/cm.

Gain switching of Nd: YAG laser has been obtained by LD array pumping with an output power of 100 mW. The gain switching dynamics of LD pumped Nd: YAG resonator was realised. A peak power of 80 mW at 1.06μm has been obtained. The calculated values are in agreement with the experimental results. A new method of high gain switching by three-step pumping has been tested. A peak power of 150 mW and a pulsed width of 0.14μm have been observed.

Two laser diodes (slave lasers) have been frequency-locked at the comb resonance frequencies of a Fabry-Perot interferometer. The measured frequency spacing stability is in the order of 10-11(τ=10s). Moreover the Fabry-Perot interferometer used as the reference in the experiment has been frequency-locked at a master laser beam. This technique can be applied to frequency division multiplexing coherent optical fiber communication.

This paper reports the fabrication process and experimental results of a 1.52 μm fiber Bragg reflector external cavity,and narrow linewidth semiconductor laser. Llinewidth of 60 kHz, sidemode suppression ratio better than 30 dB, output power of-5 dBm and a stability of 50 MHz have been achieved.

We evaluated the commutation relations and quantum mechanical Langevin equations for two-level systems and calculated the instantaneous fluorescence spectrum of atomic system driven by a strong incident field.

Using computer simulation, the higher-order soliton shaping process in CPM dye lasers was simulated. The numerical solutions of N=1.2.3 stable solitons at 610nm were obtained. The pulse width of high-order solitons is 70fs. The soliton period corresponds to about 200 cavityround trips for a light pulse.

The nonlinear wave equation was solved with perturbation method.The dispersion equation and the cut-off frequencies of the high-order TE modes in nonlinear dielectric film waveguide were given in different order approximation. The dispersion properties, the variation of effective indices and the cut-off frequencies of modes with the peak power in the film were studied and two values of the wave number of a high-order mode for a power above the threshold were found.

The various phenomena of both guided and self-guiding for a planar dye waveguide pumped by N2 laser are observed experimently. Due to additive refractive-index modulation of the double pass ASE, the dye ASE amplifier present the guided and self-guiding characteristics respectively in the x and y directions.

This paper reports the compression of SBS pulses by grating compression. It was found that SBS pulse is dominated by the linear frequency sweep and 40 ps single pulses can be obtained with a compression factor of 20.