The normalized point-spread function is applied to calculate the strehl intensity at the optimal focus and the theory of image formation in partially coherent light is applied to calculate the luminance distribution for the image of the opaque edge and a pair of line. This paper concludes that, except objective aberrations, the limit resolution of image in partially coherent light is a function of coherent parameter.

Control of temporal shape from a Q-switched Nd: YAG laser has been aohiened by an optical pulse shaper. A 1 ns main optical pulse, with less than 400 ps rise and fall time has been generated. The jitter time between the main pulse and the diagnosis pulse is less than 100 ps, close to the transmission-limited value of measure.

The positive feedback loop Composed of a GaAs switch and a pockels Cell is applied for mode-selecting and Q-switching in the Nd:YAG laser. Stable and reliable single longitudinal mode Q-switched pulses have been generated by using this technique.

A group of new equations about the field distribution and the dispersion relation as well as the propagation power is presented. The optical bistability is discussed for the nonlinear TE waves guided by a thin linear dielectric film bounded by nonlinear media.

We hare developed a Q-switoh using stimulated Brillouin scattering (SBS). The principle is described and the effect of variable factors on output characteristics is studied experimentally. The comparison between SBS and dye Q-switoh is also given.

The fifth-order nonlinear effects of medium must be included when the incident laser intensity is higher (-1013 W/cm2). By using plane-wave theory and considering both the third-nonlinearity and the fifth-order nonlinearity, the asymmetric Stokes-anti-Stokes broadening of output pulse is obtained through solving Maxwell equation directly. The theoretical result agrees well with the experimental data reported by Fork. et al..

Three-order perturbation theory is used for the study of monocrystalline GaAs. Under an assumption of a simplified but more realistic band structure of GaAs crystal, formulas of three-photon absorption coefficient are obtained. And further more, after the escape process of an excited electron being considered, formulas of thr ee-photon photoemission coefficient on a NEA GaAs photocathode are derived. The comparisons of theoretical calculated values with experimental ones are given. The experimental values are obtained by using a 2.06 μm ns pulse Q-switched laser. The theoretical values fit the experimental ones satisfactorily.

The design and implementation of an all-fiber tunable optical filter have been discussed in this paper. In order to enhance its stability, a feedback-control technique has been used here. Using propagation matrix, the characteristics of the filter are analysed. The experimental results, presented in the paper, coincide with theo retical analysis. Some possible applications of this device have been discussed.

The temporal diffraction integration in terms of temparal ABCD matrix element is introduced in an optical system. This integration is used to discuss the Gaussian pulse propagation in dispersive medium, and to show the time-imaging in a linear dispersive medium and square pulse shaping for optical fiber.

By using the 1-D projection correlation theory of 2-D correlation, the fingerprint and character field are identified repidly and effectively. The experiment, results are in good agreement with theory. Finally, the projection technique for idntifioation are discussed in detail.

A new type of fiber-optic interferometer is proposed and analysised. Based on Maoh-Zehnder interferometer, this novel fiber-optic interferometer offers higher sensitivity, together with the unique capability of compensation for optic source's wavelength and enviromental fluctuations by appropriate adjustment of its two phase.

Coherent radiation near 125 nm is generated by 61S0-71S0 two-photon resonant four-wave sum mixing (ω4= 2ω1+ω3) in Hg vapor. The two-photon resonant enhancement and two-photon resonant Kerr effect have been investigated. The optimum phase-matching conditions of plane wave and focusing beam have been analysed. The signals of four-wave parametric oscillation and four-wave difference frequency mixing have also been observed.

We have investigeted the emission spectra, absorption spectra and time resolved spectra of the K3[Re(CN)4O2] ctystal, and two lowest excited states are observed. The temperation dependence of emission intensity of the crystal is studied.

By multi-step excitation of K with any pumping wavelength between 690.0-715.0nm, oollision-energy-transfer from potassium dimer to atomic potassium, hybrid excitation, and the other processes in K2-K system, the radiation at 404.4, 404.7nm and in 470.0-590.0 nm region from high-lying states of atomic potassium was generated. The excitation and population mechanisms were discussed.

A new Inorganic material of photon-gated spectral hole burning, crystal is reported for the first time. Using the -624nm output from a CW dye laser and a 514.5 nm output of Ar+ laser (the gating light), we observed the persis-tant hole burning, which involves two-step photoionization of Sm+ in the 7F0-5D1 inhomogeneaus brodened absorption line at 6K. The experimentalts results of relevant spectral properties are given.

A flat-field grating spectrograph with one demension spatial resolution was developed. The speotrograph, consisted of a grazing incidence collecting optics combined with a cylindrical mirror and a spherical mirror, and a variable line-spacing concave grating, has not only the advantages of easy adjustment, higher efficiency and higher spectral resolution, but also the capability to provide one demensional spatially resolved spectrum simutaneously over 4.4-30nm wavelength range. The spatially resolved on-axis spectra of Si, Cu and other element plasmas produced by line-focused laser were successfully obtained. Such a spectrograph is suitable for coupling with the detectors having flat receiving surface, such as soft X-ray streak camera, to achieve the time-resolved XUV spectra.

Using a ceramic-sealed and water cooled hollow cathode D. C. discharge setup, vacuum ultraviolet (VUV) spectral radiations in range of 120-200nm for the He H2 and N2 gases have been investigated. The relative radiation intensity as a function of the discharge current (100-600mA) and the influence of the gas pressure on it have been shown. This experiment shows that the VUV line radiation belongs to the helium ion and nitrogen atom. It was found that there is only one maximum value in the hydrogen line radiation with the variation of the He gas pressure, but in the He II line radiation there are two maximum values with the variation of the Helium gas pressure. An obvious decrease of the radiation output for H2 band spectrum has appeared with an addition of He in H2 gas.

A new compound 1, 4-Bis (5', 7'-Bis-ipr-1', 3'-benzoxazolyl-2') benzene to be used as ultraviolet laser dye and named as IBOP, is introduced. Compared with the oorrespounding laser dye DPS, the IBOP has shown its better lasing properties including high conversion efficiency, photochemical stability and good solubility. In the experiments, the new dye was pumped by XeCl exoimer laser (308 nm), N2 laser (337 nm) and YAG laser with 3 rd harmonic frequency (355 nm). It is found that the compound IBOP is working in the spectral region of 388 nm to 428 nm and the laser peak wavelengths are around 400 nm in different solvents with nitrogen laser excitation. The experimental data of fluorescence spectra, UV absorption spectra, fluorescence lifetime and quantum yields of IBOP, as well as the effects of concentration and solvents, are also reported. A brief discussion is given.

A novel spectral spatial distribution measuring optical system is presented, which, is based on the principle of gateable dispersion and imaging recombination. Image quality, light condensing power and bandwidth of image are studied theoretically and experimentally. Applications in fluorescent and absorption spectral distribution measurements are discussed.