On the basis of one-dimensional Bragg diffraction analyzing method, a 2-D intensity distribution of diffraction field is derived. The experimental results are given. The factors which inflnenoe the intensity distribniion of diffracted light spot are discussed. A new idea for designing the shape of diffracted light spot is proposed,, in which the diffraction efficiency, rise time and light spot shape are all considered.

In this paper, a source encoding technique is presented for achiving superresolu-tion image. The experimental demons-tratbions show that the superresolution can easily be obtained by using this new technique. The method overcomes several drawbacks of the others and shous a new approach for further study of practical applications of the superresolution technology.

Using the phase plate calculated and designed by two-discrete FFT with dimeasionless parameters and computer simulation, the fundamental mode Gaussian beam can be converted in to rectangular shape and the elliptical wavefront can change oint circular symmetrical shape. The relation between theoretical simulation and experimental parameters were derived. Results of simulation show that the experimental equipment is simple by using the data obtained in our method and efficiency of energy transform is high.

By virtue of Fourier optics and statistical theory the amplitude and intensity space-time correlation of denamio spekle in image plane for optical imaging system have been developed. In the meantime, a novel method for extracting intensity correlation information by mixing up a coherent light field has been proposed.

It has been found that the field distribution of the particles located between the back and front positions of the front fooal plane of the 4 F system has conjugate relationship with the back fooal plane of the system through transformation of 4 F Fourier lens system. This relationship has unfavourable effect on depth of field and determination of the particle position. The fringe visibility and edge contrast of the particles are improved by the amplifying of the lens system. However, the quality of the particle recording and reconstruction will be reduced if the amplifying of the system is beyond 4 times.

A digital image restoration algobrithm is discussed which can eliminate the influence of non-uniform intensity distribution of diffraction halo and enhance the accuracy for computer to analyze speckle photography fringe pattern automatically. The comptlting program is also presented briefly. Test results using the algobrithm and the program to deal with analogous white light speckle photography fringe whthout noise are very satisfactory.

In this paper, a new method of speckle photography-radially scanning apertire method is proposed, and theoretical analysis and experimental results are presented. This method has the advantage of recording the whole dynamic process of an object on one speckle photogram. The information of deformation in the direction of x and y axis and of 45° at any moment can be obtained in the form of isothetio fringes by whole field filtering.

The dispersion produced by an ordinary single stack cavity mirror is analysed. This kind of mirror is difficult to compensate the upehirp of the pulses in the cavity. A kind of double ooated stack mirror, with the suitable amount of dispersion of φ(ω) =1.3 ×10~(-28) sec2 for upchirp compensation is designed and used as cavity mirrors, so that pulses as short as 30 fs are generated directly from a simple oolliding-pulse modo-locked (CPM) dye laser without additional dispersive elements in the cavity.

In this paper the deeply thermo-stable characteristics of telescopic resonators with G parameters satisfied the condition G1G2 = l/2 are theoretically discussed in detail. An exact expression for the telescope defocusing which can compensate thermal disturbance is derived analytically. It has been shown that the simplified approximation formulae of the defoousing in Refs. [4] [5] can be easily deduced from this exact formulation if the appropriate assumptions are adopted. Computer simulation and numerical calculation are carried out to confirm our theoretical results and the curves which describe the variation of beam sized with telescope-resonator parameters are given.

In this paper, we analysed the ablative process by which an UV exoimer laser can remove organic material. The etch depth per laser pulse as a function of incident energy density were explained by theoretical model. For polymethyl methacrylate, two photon processes play an important role at high incident energy density. The relationship between etoh depth per pulse and absorption coefficient of the organic material were also discussed. There is a maximum of etoh depth per pulse for a special absorption coefficient.

In this paper, a new grating-diffraction interferometry with partially coherent illumination is proposed. As a foundation, the partially coherent diffraction effect of gratings between the Talbot and the Lau effects is firstly treated. A new type of interferogram is resulted in such a new interferometer, that is characterized by two gratinglike carriers of doubled spatial frequency. Simply by the adjust-ment of the source slit the interferometer will become the Talbot interferometer and the Lan interferometer, respectively, at the two extremes of illuminatoin coherence. The performance of the system is analysed by the ambiguity function. Experiments are given too.

With the aid of computer simulation, we study energy spectrum erolntion of the fundamental solitons propagating in fibers, caused by Raman self-pumping. We find that the self-frequency shift effect will be accompanied with bandwidth change and energy spectrum distortion of the solitons whose durations are shorter than sub-picosecond.

According to the J. Upatinick s principle of elliptical equi-optioal path, we suggests a holographic method for in situ observing the effecting coherent length and TC periodicity of the multi-lengitudinal mode laser. It s basic principle is described and relative experimental results are given in this paper.

The two-photon resonant transitions of high electronic state (E) of IBr molecule have been observe using the technique of the multiphoton ionization spectra. Aooording to the vibrational spectra of IBr with the Franok-Condon principle, we have obtained for the first time the rotational constant Be of state (E) of IBr, which is (0.0653±0.0003)cm-1.

Photoionization spectra of the Sm atom near the ionization limit have been studied using stepwise laser excitation and ionization methods with two pulsed tunable dye lasers. More than seventy energy levels of Sm have been measured which were located in the 45821.8-45802.9 cm-1 energy interval.

Weak absorptions of optical coatings are measured by transverse photothermal deflection speotroscopy (TPDS) with a sensitivity of as high as 10~(-5). The experimental results are in good agreement with those measured by a laser calorimeter.