In this paper we present a new model for interpreting Lau effect on the basis of partial coherent transfer function in free-space propagation. The generalized formula for description of intensity distribution of Lau fringe is deduced. It is suitable for arbitrary periodical amplitude or phase objects. The condition of producing Lau fringe and output intensity for some typical periodical objects is analysed. The experimental results of Lau fringe produced by line gratings with different periods are given.

In this paper, the fundamental principles of stroboseopic speckle photographic method is discussed.For a specklegram of harmonic or non-harmonic periodic vibrations in whole fieldanalysis, the analytic formulae of the distribution of the mean intensity of light and visibility of the fringes are given. Both theory and experiments show that stroboseopic speckle method is obviously superior to time-average method.

The loss in an injection Febry-Perot spherical cavity is very sensitive to the output intensity of optical beam. This behavior can be used for absolute measuroments of the cavity loss, even if the loss is very weak. The method has high contrast, high sensitivity and precision. The measurement system and its potential applications are presented.

The properties and distribution of defects in Nd:YAG crystals are successfully obtained by means of X-ray transmission topography with AgKa radiation. It is shown that there are several kinds of defects, such as growth striations. precipitated particles. edge dislocations, screw dislocations and mixed dislocations formed by dislocation motions in 2Sd:YAG crystals grown by CZ and Temperature Gradient Techniques (TGT). Some experimental results are consistent with the results obtained by optical methods, however，X-ray method bad its special advantage in discriminating the properties of dislocations.

A way to reduce the cut-off thicknesses of the fundamental modes in slab waveguides with prism couplers was presented. The MgO film parameters (refractive index and thickness) were measured by use of the quasi-symmetric waveguide method described in the paper, and the measurement results were given.

In this paper we extend the theory of synchronously pumped mode-locking and obtain the precise solution, i.e. supermodes solution. The physical meaning of the supermodes solution is given. Under the condition of the lowest supermodes, the analytic expressions for pulsewidth, intensity and peak position are deduced. The effect of noise on supermodes solution of the synchronously pumped mode-locking dye laser is studied. The expressions for the spectrum of noise, the method of evaluating the noise source and the ratio of noise to signal are also obtained.

The anisotrop of ion emission was observed when laser irradiation of the aluminum or gold targets at 1.06μm wavelength with laser intensity of 1012 to 1014 W/cm2 and configurations of spot-focused and line-focused. The scaling law of ion velocity and the mass ablation have been studied with the analysis of ion emission, the ani-sotropic angular distributions of ion velocity and momentum.

The resolution of Darkfield and Phase Contrast Microscopy is up to 10-500A. The fine structure of point defect clusters, small size dislocation loops and helical dislocations in Nd:YAG crystals can been observed very clearly by these techniques, especialy, the image of the undecorated edge dislocations and mixed dislocations in crystals have also been got from them. The observation of undecorated dislocations was confarmed by chemical etching. optical birefringence and X-ray topography.

The evolution operator of state for degenerate parametric down-conversion has been obtained. By means of state function we have studied the statistical properties of light field at degenerate parametric down-conversion.

The Doppler-free saturated spectroscopy of the CO2 and SF6 molecules is investigated experimentally by using optoacoustic detection with a resonant multipass cell. The width of the absorption dip for CO2 is measured to be about 2.5 MHz, five absorption dips for SF6 are observed in the experiments, and the dip width is about 1.9MHz. In both oases the spectral resolving power is greater than 107.

Diffraction integral formula for general nonsymmetric optical systems is clearly derived by means of vector analysis. Based on the concept of tonsor complex curvature of radious, the ABCD law for nonsymmetric optical systems is presented. Also, an applying example is illustrated.

The present paper has discussed some characters of appraximate Talbot self-imaging phenomena for incident spherical Gaussian beams. Upon using Talboi self-imaging a convenient way for measuring divergence angle of Gaussian beams and ultra-high amplification of the self-imaging in some condition are also proposed.

We have constructed Fresnel rhombs used as a λ/4 or λ/2 wavelength plate. This design was based on Fresnel s principle in a total internal reflection. We have made a transformation from a linear to a circular polarization or a rotation of a linear polarization vector in ultraviolet spectral legion.

Interference fringes with a tilted wavefront are spatially scanned perpendicularly to the carrier fringes and analyzed using FFT algorithm. It is not necessary to use any device in order to modulate interference fringes temporally. Itis also not necessary to locate fring centers and to assign interger order number. In this paper. we propose these techniques for determining the topography of a wavefront from an interferogram. The accuracy is higher then standard deviation of 1/50 wavelength.

The (2+2) four-photon ionization spectra of NO via A2∑+ (v=0) and A2∑+ (v = 1) states are assigned and (3+1) MPI spectrum via F2A (v=0), H2∑(v=0) and H 2(v=0) states is discussed. Some intensity-anomalous lines of (2+2) MPI have been observed. Based on the signal-power dependence measurement for the normal and anomalous lines, a double resonance and collision Ionization model is suggested to elucidate the intensity anomaly.

We have observed 682.8 nm collisional induced fluorescence emission and it s relaxational oscillations in optically pumped Ba/He mixtures. Theoretical analysis and numerical calculations are presented and the results coincide with experimental observations.

The fluorescence spectrum of BeAl6O10:Cr crystal consists of seven narrow lines and a broad b and. The difference between the lifetimes of the broad band and the lines is very big even at room temperature. There is less relationship between the band emission and the line emissions in BeAlGO10:Cr, unlike in BeAl2O4:Cr. To identify the Cr centers, experimental study has been carried out. Based on the temperature-and the concentration dependence of the line intensities, we suggest that three mainlines result from two types of single or oeniers, and other two linee oome from Cr pairs centers.

Considering the absorption taking place during the back and forth passages inside of the opticl films, and the optical films being "thermally thin" in photoacoustics, a photoacoustic expression for optical thin films is deduced according to the one-dimensional heat-flow piston model. The amplitude of photoacoustic signal is proportional to the absorptivity of the film. Some photoaooustio absorption spectra of films on glass are measured, which is in agreement with the theoretical expressoin. This photoaconstic spectral meiihod shows high sensitivity and precision, particularly Hi table for measuring tlie alosorpiiion spectra of weakly absorbing films.