Demands for ultra high precision non destructive detection of micro bulk defects in materials have manifested as microelectronics and micro electro mechanical system (MEMS) rapidly develops. But at the same time, although many high precision non destructive defects detection methods exist now, they still can′t meet the requirements at all. In this paper, after having established a mathematical modeling of detecting micro bulk defects by Rayleigh & Mie theory, a novel way, which collects scattered light in the direction vertical to the incident laser and can detect micro-bulk defects in materials, is proposed. In order to prove the rightness of the modeling and technique, simulation experiments on microsize diamond particles are implemented and the scattered graph collected in the direction vertical to the incident light is processed. Satisfactory result is achieved which demonstrates that the scattering modeling and technique are correct and that the LST non-destructive detection of micro-bulk defects is feasible.

The 2D5/2 metastable level population densities in the early afterglow of a magnetically confined copper vapor discharge were measured with the self absorption method. The relaxation of the metastable atoms was investigated in comparison with that in conventional copper vapor laser discharges. Analyses of the relaxation mechanism in the magnetically confined discharge were given.

A simple photoelectric system is described in this paper. We choose the optimum diaphragm through measuring the optical transfer function with different dimensional double ringed diaphragms.

The view angle of the rainbow holograms recorded by using the method of a pre existent slit is analyzed, which shows that the rise of the energy efficiency in this method will result in a reduction of the view angle. A single method of making rainbow hologram with high efficiency and a reduced view angle loss is presented and experimentally demonstrated.

In this paper, we report that a cured acrylate based film is selected as the record layer of CDs. Its absorption coefficient at 633 nm and 780 nm and the glass transition temperature are measured, which is a characterization of stability. With the theory of heat absorption, the temperature field distribution is computed based on the typical CD ROM structure. The results show that the temperature rise around an aluminia reflector has a significant influence upon the stability of the record layer.

The behaviors of the writing and readout of the real time hologram in a bacteriorhopsin film are investigated. Due to the saturation absorption, there is a most suitable writing intensity. Two readout modes are discussed, and the results show that high diffraction intensity can be obtained for the pulse readout mode.

The nonlinear distortions of the erbium doped fiber amplifier (EDFA) in the AM CATV optical transmission system is analyzed and calculated. A new scheme compensating the nonlinearities of EDFA——optical compensation is proposed and the other two compensation methods are introduced. The results of the computer simulation and experiment indicate the distinct improvements for the nonlinear distortions of the EDFA using the optical compensation. At last, the three compensation methods are compared.

The nonlinear distortions of the erbium-doped fiber amplifier (EDFA) in the AM-CATV optical transmission system is analyzed and calculated. A new scheme compensating the nonlinearities of EDFA——optical compensation is proposed and the other two compensation methods are introduced. The results of the computer simulation and experiment indicate the distinct improvements for the nonlinear distortions of the EDFA using the optical compensation. At last, the three compensation methods are compared.

Influence of the incident polarization state drifting off TE mode on composite second order distortion (CSO) and composite triple beat distortion (CTB) of an optical fiber AM CATV externally modulated transmitter is analysed theoretically. The conclusion is that if the insertion losses of the TE mode and TM mode are same and 59 PAL D channels are transmitted, the deviation angle from the TE mode should be less than 6 degrees with CSO=-70 dBc. The result of a single channel transmission experiment is consisistent with the theoretical analysis.

A 2 kW CO 2 laser has been used to deposit single tracks of Ni based WC alloy onto a steel A3 substrate. Effects of laser processing conditions and weight fractions of WC particles on the cracking tendency of coatings are studied. Results show that WC particles are the weak points of cracking in the laser cladding composite coatings, but when WC proposition is higher, the cracking numbers in composite coatings will decrease. Effects of laser traveling speed on the cracking tendency of coatings will be altered at various WC weight fractions.

Based on the experimental data of flashlamp radiation and Nd:glass absorption spectra, a numerical simulation model for the multisegment amplifier (MSA) has been proposed by using the ray tracing and Monte Carlo methods. Numerical calculations have been performed to illustrate the dependence of transfer efficiency and the stored energy density distribution on the geometrical dimension and configurations of the MSA.

An average power of 50 mW was experimentally obtained in a Ca + recombination laser. The properities of the Ca + recombination laser were studied with varying operation parameters, such as buffer gas pressure, pulse repetition rate and input electrical power. The parametric relation has been measured and the operation characteristic was analysed briefly.

Amplified spontaneous emission (ASE) can strongly affect the operation and efficiency of high power laser devices. In this paper, starting from the laser rate equations and in consideration of the temporal and spatial pump rate distributions, the ASE in a multisegment amplifier (MSA) has been studied in detail by using two dimensional ray tracing and Monte Carlo methods. Numerical calculations have shown that gain distributions at the horizontal section of the middle slab are dependent on the time and pump

By using the pulse sequence model and the successive iteration method, the inverse problem of multistage and multipass pulsed laser amplifiers, namely, to find the incident pulse shape and fluence from the given output pulse and multistage/multipass amplifier parameters, is studied and simulated numerically in detail.

A proposal of the improvement of high voltage pulse of pseudospark discharge is given. The experimental device is presented and its possibility is analyzed theoretically. Thus the outline dimension of the traditional free electron laser (FEL) will be reduced greatly, which makes the compact FEL practical.

In this paper, we have discussed the design and the making methods of the series resonance power supply for the He Ne Laser.

This paper gives a brief introduction of the theory about dark spatial optical soliton, and analyses the effect of boundary condition on dark spatial optical soliton in a Gaussian light beam by means of numerical computation.

In this paper, the experimental results of the electroinduced second order nonlinear optical effect of several kinds of semiconductor microcrystal doped glasses are reported. The mechanism of the effect is also discussed.