A novel discrete cosine transform (DCT) based automated phase measurement method is proposed and verified by a simulation and experiments.

A kind of high performance tilt mirror have been designed and made, and two kinds of correction system have been experimentally realized. One is "try and error" hill-climbing system controlled by micro-computer, the other is a dithering hill-climbing system. Experimental results show that both systems can correct intracavity tilt aberration successfully. The merits of these two correction systems are compared with each other.

This paper reports on the technique and results for the measurement of lifetimes of highly-excited atomic uranium levels with the three-wavelength/three-step photoionizat ion process.

Picosecond photoconduetive sampling system is constructed, which consists of a mode-locked dye laser synchronously pumped by a mode-locked argon ion laser and the photoconduetive switch using SOS as substrate, and the response time of ultra-high-speed photodiodes and the dispersive broadening effect of coaxial connectors have been measured.

A careful analysis about the angle between the optical surface and the optical axis of the crystal birefringent filters used in CW dye lasers tells us that when the angle is about 30-35°, the tuning sensitivity of the filter gets to its maximum.

Though the absorption method for measuring transition probability is an effective one, it is insensitive because of lower absorptivity. Here we introduce a new absorption method by using modulated HCD with higher sensitivity, and with this method we measured the relative transition probabilities of the six transitions from the ground state of uranium 238 to the excited states including the 16900 cm-1, 17361 cm-1 levels.

Cytotoxic effect of the new photosensitizer hypocerllin plus light exposure on PTK2 and heLa cells in vitro was studied by means of He-Ne laser microirradiation. The absorption spectrum and HPLC of hypocrellin were also investigated. It showed that hypocrellin might be an effective photosensitizer in photodynamic reaction.

A new method to computetion of HOE by direct solving coherent equations is discussed in depth. The parameters of CGHOE can be obtained directly if the method is used in the computation.

Holographic lens arrays and elliptical zone plates are fabricated on holographic plate and photoresist by using interference of the 1st order diffraction and the 2nd order diffraction beams from ion etching Fresnel zone plate obtained by electronic beam scanning and deep ultraviolet lithography techniques. The experimental results of focusing and images produced are given.

A method is put forward for controling the contrast of optical images in real-time by using two phase conjugate mirrors. The theoretical analysis is made, an experi-mental scheme is proposed and the simulation results are given.

A method of optical matrix multiplication using Modified Signed-Digit (MSD) arithmetic and multi-window decoding optical symbolic substitution rule is proposed and realized. It opereates at high speed and high accuracy, and multiplies experimentally two 22MSD matrix in 32 bits one second.

This article presents our experimental procedure of carbon-tungsten alloys cladding treatment on No. 60 steel surf ace by means of a high power CW CO2 laser. The experimental results indicate that a carbon-tunsten alloy cladding on a poor quality steel surface greatly improves its mechanical properties, the cladding thickness are inversely propotional to the square of laser scanning speeds.

A low threshold three-segmented composite cavity GaAlAs/GaAg laser is reported with a lowest CW threshold current of about 18 mA. It operates in stable single-mode, external differential quantum efficiency is 50-80% and the best linear relationship between light output and current remains up to 30 mW. Single frequency oscillation locking is achieved over the temperature range of around 5°C and the highest temperature for CW lasing is 117 ℃.

Through numerical solution of the Schrodinger equation we illustrate the effects of frequency modulation laser upon the excitation of a four-level system irradiated by simultaneous laser pulse. When the laser power is sufficiently great and the frequency modulation parameters are suitable, it shows that the frequency modulation excitation applied to a Gatlssin statistical distribution of detunings can obtain more effictive three-step photoionizatioa than monochromatic or amplitude modulation excitation does.

According to principle of the angle of laser incidence relation to jet of laser-produced plasma, we designed a novel target which can make laser-produced plasma convergent. At the above condition, we found enhencement of LPX radiation. The experimental and the theoreticaly results show that enhencement phenomena are caused mainly by strong plasma convergence.

Some new interesting experimetal results are reported about the characteristies of ion emission produced from targets with different sizes and forms by line-focused laser. Temporally resolved ion singnals have been diagnosed by Faraday charge collector. It was found that the anisotropic angular distribution of ion emission under line-focused condition was weakened when laser irradiated the targets with cold pit.

A discussion is given on the major process of CPM that two pulses collide in the saturable absorber and presents a physical picture to describe this process, and a new brief and clear explanation is given to the physical machanism of CPM.

Studied here are eollisional broadenidg of Raman energy levels of atomic barium by buffer-gas molecules, its effects on the Raman gain coefficient and Eaman conversion effiency.

This paper reports a N2 laser filled with 95% N2 and 5% SF6. Using the intracavity structure the output pulse energy and power are increased by a factor of over 50%. Its output energy per pulse is up to 24.3mJ, pulse width >15ns, energy fluctuation 2.8%, efficiency 0.05%.

We have made comprehensive investigations over the optogalvanic effect of neon with RF discharge, and revealed the general characters of the polarities and spatial behavior of the signal with the variation of discharge intensity. Qualitative explanations are given. We also measured the high lying states by detecting the optogalvanic signal of two-step excitation of two pulsed dye laser, and recognized states as high as 46d' at the lowest discharge intensity. In addition, we observed the signal of two-photon transition of neon at 592.3 nm by focusing the single pulsed dye laser beam.

Luminescence properties of Zn WO4:Cr3+ laser crystals were investigated. 4T2 energy level of Cr3+ splitted to three levels, 13550, 14205 and 14706cm-1, and the Stokes-shift of luminescence spectra is 236nm. The best intensity peak of emission is at 912nm. If the excitation wavelength was selected as 608nm and doping concentration was 0.01 wt%, a broad emission band would be observed at 532nm excitation.