The operating characteristics of a colliding pulse mode-locked ring dye laser using DODCI and DQOCI dye as saturable absorbers are studied. Measurement results of the dependence of the pulse width of the mode-locked pulses, the stability range of laser for stationary single-pulse operation and the threshold pumping power on the concentration of the absorber dye are given. Stable pulses with duration of 0.12 psec and peak power of 1kW can routinely be obtained with this laser at a low pumping power (about 2 W). The results of the spectrum-resolved SHG correlation measurements of the mode-locked pulses also axe presented, which confirmed the presence of frequency chirping in the pulses. It has bean found that by using DQOGI dye as the saturable absorber the spectrum of tlie laser output consists of two separate parts located in the yellow and red regions respectively and when the oscillation in yellow is supressed the modelocking stability is improved and the output pulses exhibit clean pulse shapes with much reduced wings.

Laser-produced X-ray spectra of H-like, He-like and Li-like ions as well as K lines have been taken and identified with an X-ray crystal spectragraph in the range of 4～22A for Z = 8～14 elements. The o, p satellites which were theoretically predicted have been found experimentally at the redside of intensive resonant lines of He-like ions for the first time.

Using a classical single particle model of free electron laser, the effects of a uniform axial magnetic field on the gain of a free electron laser with linearly polarized wiggler were discussed. Gain enhancement near magnetic resonance was obtained.

Raman speotmm of the silicide "WSi2, which occurs at 333cm-1 and 456 cm-1, has been demonstrated. Formation of silicide from co-sputtered WSix was studied by Eaman speotroscopy.

The diffraction self-imaging phenomenon of the grating in the optical system-general Talbot effect, is studied with aid of the Fresnel-Kirchhoff integral in the Fresnel approximation. The geometrical imaging is considered as a special case of Talbot imaging. According to Talbot formula, the properties of the diffraction self-imaging of the grating illuminated by parallel and spherical wave are discussed respectively. Finally, Talbot effect is explained by the method of the interference.

A new type of optical modulator is described in this paper. The principal couple circuit, modulating characteristic of the modulator, the measuring method of the modulation parameters, its experimental results and applications are presented. The function of this modulator is significant for laser technology.

By using a simplified electrostatic sphere on core diode model (SOC) the relative spherical aberration coefficients Cr of the magnetic field superimposed field emission gun (MFFEG) were numerically calculated. Here Cr is the objective side spherical aberration coefficient nomalized with respect to the spherical aberration coefficient in the absence of magnetic field, it provides a measure of the additional factor by which the electron source size is degraded as a result of the superimposition of the magnetic focusing field. The position of the real Image (the electron probe) could be adjusted easily by changing the exciting strength of the magnetic field. The Cr of bell shaped magnetic field has the least value among these 6 theoretical fields. Calculation suggested that the spherical aberration of this MFFEG system could be less than a pure field emission gun followed by a separate magnetic condenser lens. As an illustration, the MFFEG system with 10 mm magnetic field width could produce a beam crossover of 1 μm diameter (limited by spherical abberation) at 200 mm from the cathode, leaving a large free space around the specimen, for surface current density of 1.0×10 10 A/m2, the current into the crossover would be approximately 8 μA.

Anomalous nonlinear increasing in transmissivity of aluminium foils in the wavelength range 8～11 A has been observed. These foils were irradiated with the monochromatic X-ray radiation at about 5×102 W/cm2 generated by a high-power neodymium-glass laser.

The design features of a large-aperture zoom lens tor 35 mm motion picture camera are presented. A structure of a fixed part between two moving parts in order to correct astigmatism is discussed. A new-type zoom lens is given as an example. It has a range of focal length of 25～85 mm, a relative aperture of 1/1.4 and maximum angular field 67°～18°.

A simple method for Zernike polynomial fitting in fringe analysis is given. Though the method is still based on a Gram-Schmidt orthogonalizing technique, it is not necessary to orthogonalize the polynomials during fitting. The linear transposition of the covariance matrix of the polynomiala can work out the Zernike coeflicinces directly. So it offers a better algorithm to Zernike polynomial fitting.

In this paper, mathematical relationship among parameters of lateral-rotation shearing interference and possible important applications of this type of interference are discussed. The basic relationship between lateral-rotation shearing interference and lateral parallel shearing interference is also established. It is proved that a simple single-flat-plate shearing interferometer used for parallel beam testing may be used to replace the prism shearing interferometer for convergent beam.

The laser self-ulsing modulation (LSPM) has been observed in He-Cd laser and the paramaters related to this phenomenon have been measured. The LSPM has been found to be intrinsically different from the laser noise caused by the moving striation. The suppresion of the LSPM is briefly discussed.

The expressions of optical and spectral properties of inhomogenous media consisted of ultrafine silver particles-transparent media have been derived using the effective Lorentz oscillator. The expressions have many advantages, such as simplicity, obvious physics significance, and direct determination of the position of the absorption band. Transmission spectra of ultrafine silver particles-transparent media calculated by effective Lorentz oscillator are in agreement with the measured transmission spectra.

The absorption, fluorescence and excitation spectra of titanium-contained fluoro-phosphate glass have been measured. The results show that Ti3+ ions in the glass are located at disordered octahedral sites. With UV 250～320nm excitation of the charge transfer band a visible 0.55μm luminescence has been observed. The band-width is 180nm. In the excitation spectrum the peak position is located at 290 nm. Furthermore, time-resolved fluorescence and relaxation spectra of Ti3+ ions in the glass have been measured at room temperature and 77 K, respectively. It is found that the fluorescent peak positions move from 510 nm to longer wavelength 610 nm at liquid nitrogen temperature and the spectra become diffused with the increase of delay time up to 30 fis, while a little change occurs in the spectra at room temperature. The fluorescence life-times of 5~12 at low temperature are dependent upon the emission wavelengths. On the contrary they are 13 μs and independent upon the emission wavelengths at room temperature. In addition, the condition and possibility of the emission of Ti3+ ions in inorganic glasses are discussed.

Site-selective spectra of Eu3+ ions in the La-phosphate glass were measured using laser-induced fluorescence linenarrowing technique. The excitation source was a flashlamp pumped Rhodamine tunable dye laser. In the experiment four main kinds of site-selective spectra with the remains of inhomogeneously broadening were obtained. These site-selective spectra fit to conventional spectrum measured at 77K for 5D0-7F1 transition of Eu3+, and favourable result has been obtained.

Two approaches for improving the method of extracting thin-film optical parameters from spectrophotometer measurements, developed by Case, have been presented: (1) The same unknown thin film was evoporated on two different substrates and the measured reflectances R of the two films at one wavelength were then used for determining the parameters; (2) The unknown thin film was evoporated on one Substrate and its measured reflectances E at different wavelengths were then used for determining the parameters. (2) The unknown, thin film was evoporated on one Substrate and its measured reflectances R at different wavelengths were then used for determining the parameters. These two approaches are not only easy, but also provide higher accuracy.