In this paper we present a design of optical time-division multi/demulti plexing (OTDM) system. Experimental results obtained with ZnS interference filters are also presented. The system is expected to be used in the optical communications and the optical computing by replacing the ZnS switches with high speed ones.

A method of Moire topography testing with double computer-generated gratings is proposed. It is concluded from theoretical analysis that the lateral derivative of the kernel of the projection grating being a constant is the necessary condition for the uniform accuracy testing. Under the proper designation of grating kernels, the standard model can be characterized by equalinterval straight fringes. Therefor, the defect of the tested object can be found directly and quantitatively form the deviation of moire fringe from the background pattern. Finally, computer simulations and experimental verification on the test of a torid surface are presented.

In particle Image velocimetry, a thin laser beam is usually used to interrogate the double-exposure photographic image point by point in order to find out displacement of the particles. In this paper, the relation between the choice of interrogation region size and the displacement of the measured particles is daduced by analyzing the effect of Size of the region upon the speckle distribution and the influence of the speckle noise upon the disc-rimination of the Young's fringes. The problem that the size of the interrogation region places a restriction on the maximum displacement to be able to measure and the criteria for reasonablly choosing the interrogation region are discussed and analyzed.

A new technique of recording true-color rainbow hologram of 3D diffused object is presented. Based on the conventional one-step true-color rainbow holography, the hologram can be recorded in olny one kind of recording material with single exposure by means of conjugate reconstruction against the original optical geometry with one wavelength laser. This technique is particularly suitable for making photoresist relief master hologram of true color embossed holograms.

Using the well-known KMR equations and combined with BFEL's overall experimental parameters, this paper presents a study of Optical Klystron (OK) configuration for the Beijing Free Electron Laser (BFEL) which will start to operate recently. The effects of the laser input power, electron beam energy distribution and its current, dispersion magnetic field, drift region distance and its position in the wiggler, upon the Free Electron Laser gain, are analyzed in detail. Based on the oscillator configuration of BFEL, a group of practial optical klystron parameters with a suitable beam energy spread has been put forward and the analyses of its saturation power, power spectrum, and tapered wiggler also have been made.

A dye Q-switched laser with nonlinear active multi-functional crystal NYAB is realized by using xenon flash lamp pumping for the first time. A 0.53μm pulse of 3 ns pulse duration and 1.28mJ energy (6MW/cm2 peak power) are obtained when small signal transmission of dye T0=0.3 and laser resonator length L= 10cm. Meanwhile, the relations between energy, pulse duration, and peak power of 0.53μm the laser pulse and L, T0 are measured. Moreover, the equations describing the mechanism of NYAB dye Q-switched laser in the case of L longer than rod length are derived. The theoretical results obtained by solving the equations are in agrreement with experimental results. In addtion, the ways of increasing the peak power of NYAB Q-switched laser are discussed.

A pulsed Ti3+:Al2O3 laser has been operated by using a 10ns frequency-doubled Nd:YAG laser as pump source. The maximum output energy of 37mJ, energy-transformation efficiency of 40%, slope efficiency of 40%, quantum efficiency of 80%, and the pump threshold about 0.5-1.2J/cm2 are obtained from this system. The output wavelength can be tuned within the range of 662-938 nm.

The laser output power of the dimer of O2 (1Δg) was estimated theoretically. By means of microwave (2.450GHz) exciting high pure oxygen to generate the dimer of O2(1Δg) in experiments, the laser oscillation of the dimer of O2(1Δg) was realized at 656 nm for the first time with stable flat-concave resonator. When the pressure of oxygen was 133.3Pa, the power of microwave was 600W, the laser power was as high as 100 μW, this corresponded to theorectical estimation in order of magnitude. In addition, the diverge angle measured was about 37.3 mrad.

The far-field output characteristics of throe-channel hollow bore ridge (HBR) waveguide arrays CO2 laser are investigated theoretically and experimentally. The far-field patterns of three different output modes are observed. Since there is a difference between the experimentally measured values and the theoretical values at normal hypothesis, the normal hypothesis conditions are revised in this paper, and the theoretical expression is derived. It is in agreement with experimental vesults.

Zeeman coherences with Am = 1 and Am=2 are observed in the ground state of natural rubidum vapor optically pumped with a laser diode pulse train. The laser pulse of approximately 200ps at 780 nm are produced by gain-switching through direct modulation of the inject current of the laser. Δm=1 coherences are detected by a probe beam using the polarization speotrosoopy technique, while the forward scattering spectroscopy technique is used to detect the Δm=2 coherences.

A systematical study on pulsed Nd:YAG laser mode-locked by intracavity frequency-doubling crystal KTP is presented in this paper. The expression for the output pulse width and a comparison with the experimental results are given. It Shows that the theoretical calculations agree with the experimental results dramatically. The effects of varying each experimental parameters on the properties of laser output are also analyzed and discussed.

In this paper, according to the dynamic and steady state equations describing the magneto-optical bistable system with a delay in the feedback loop, some instability characteristics have been calculated and analysed. In particular, the effect of extinction ratio in the magneto-optical bistable system on the unstable region and the resonance have been investigated.

In this paper the factors which influence the isolation and the insertion loss of optical circulator are discussed. Theoretically and experimently ther is an optimum chioce between absorption and polarization characteristics of polarizing prism for a polarization-incependent optical circulator with low insertion loss and high isolation. Experiment shows that the insertion loss of our circulator was about-1dB and the isolation was between - 25.5dB and - 28dB.

This paper reports the research result of GaAg 2×2 asymmetric Mach-Zehnder waveguide switch/modulator. The mechanism of this device and the factors of crosstalk are analyzed. Instead of traditional Y-branches, two asymmetric X-junctions have used in the switch. An 3d B coupler with good performance is obtained. The device operating at λ=1.15 μm has a 12 V Switching voltage and a crosstalk ratio less than -22.4 dB. This kind of switch will find application in the switching arrays.

In this paper, the two-wave mixing properties of tetragonal phase Fe doped KTN crystal are repoted for the first time. A gain coefficient of 7.3cm-1 and diffraction efficiency of 42% were measured. The response time is 2.8 seconds. The Sign of the dominant oharge carriers is determined and some other parameters are calculated.

A laser Doppler velocineter system in which ordinary single-mode eptical fibre is used to form the all optical paths is described. The velocity direction sensing is performed by an acoustic-optic frequency shifter using ordinary single-mode fibre. Single-mode fibre polarisation controllers are used to provide adjustment of the polarisation State in fibre exits. This system is simple, miniature, flexible and easy to adjust because of the all fibre configuration.

Laser optogalvanic 'spectroscopy has been performed in three new odd-parity levels and two other previously reported ones of 139La I. The observed hyperfine structure spectra are analyzed and the magnetic-dipole hyperfine structure constants A of these levels are obtained by least-squares fits.

Temperature distribution of TiO2 single layer irradiated by 10ns, 1.06μm wavelength laser pulse was calculated with thermal transfer equation. Following conclusions were obtained; to improve thermal parameters of coating can reduce the peak temperature obviously, the thermal parameters of substrate have little effect on temperature response of coating, temperature distribution of thin film depends on the electrical field distribution. The peak temperature of coating with a quarter-wavelength optical thickness is lower than that of coating with a half-wavelength optical thickness.