This paper presents the experimental results on the generation of continuously tunable UV laser radiation in the range of 2800 A to 4100 A. The laser output at 0.3m~0.4m is generated with frequency-summing of the fundamental wave (NdlYAG laser, 1.06 pun) and the output radiation of OPA (continuously tunable from 0.42m~0.7m) pumped by the fourth harmonic wave (0.26m) of Nd:YAG radiation at 1.06m in KDP crystal. Continuously tunable UV laser output at 0.28m~0.3m is generated by frequency doubling the output of Nd:YAG laser SHG (0.53m) pumped rhodamine 6G dye laser pumped by the second harmonic of Nd: YAG laser in an ADP crystal.

The characteristics of active and active-passive mode-locked phosphate glass oscillators are reported. Active mode- locked pulse duration was about 200 ps with relatively stable output. For an active-passive mode-locked laser with a pulse duration of 7 ps, the probability for occurring satellite pulses was related to the. modulation index of the modulator. Using various intracavity etalons, the pulse duration of 30 ps and 70 ps were generated without satellite pulses. The performances of the active-passive mode-locked laser are better than that of the passive one.

The experiment of the three-photon resonance ionization for detection of atomic potassium is described. The dependence of photo-ionization signal on light intensity was measured. The expected saturation effect of ionization was obtained and the number of atoms detected with each light pulse was determined as 6X108.

The transition intensity parameters and the transition probabilities of the Nd3+ ions in LNP crystals have been calculated.

With 20 ps ultrashort pulses as the gating pulses and the nitrobenzene as Kerr medium, an optical gate which stays open for 60 ps has been made. The effects of various factors on transmissivity and switching time of the optical gate are discussed. A new scheme for collinear optical gate is suggested and the experiments have been carried out successfully.

This paper describes an ultra-high frequency electro-optic crystal modulator for laser mode-locking and other cases. Modulation depth of the modulator and- the design calculation of its match electronic circuit are discussed in particular, and experimental results at the modulation frequencies of 100 MHz, 200 MHz and 400 MHz, are given respectively. These results coincide with the theoretical expectations.

A new method to detect laser mode by using half-tone processing technique is presented. Using this method, two-dimensional equi-intensity contours of laser mode were obtained. It is not only applicable for the CW lasers, but also for the pulse lasers.

The potassium-mercury lamps and potassium-rubidium lamps made by PGA tubes used to pump Nd3+:YAG lasers were studied experimentally in repetitive frequency operation and were compared with similar xenon flashlamps. In certain range of electrical input power, the overall laser pumping efficiency of a K-Hg lamp is 60% higher than that of the xenon lamp. Some special technological problems were investigated and the orientation for further study of alkali-metal vapor lamps are presented.

This paper discusses the principles on the illumination of speckle effect and maintenance of resolution by holographic microscope using image plane holography, as well as the conditions for keeping the resolution of the image. Experimental results in eliminating the speckle effect and the reconstruction with white light are also presented.

According to Lohmann’s general theory on computer-holography, the principle of the computer-generated holopram of interference-fringe type is explained. An improvment upon the calculation procedure of Sirohi et al. has been made. It raises the accuracy and reduces the required time a little. A prototype hologram that reconstructs the required wavefront with an accuracy of 1/20 wavelength (rms.error) has been produced for testing a parabolic mirror (f=1021 mm, 2r0=214 mm), which shows the defects of the tested element.

The phase conjugation characteristics of backward stimulated Brillouin scattering (SBS) are experimentally investigated. The intense backscattered radiation is observed in GS2 using a giant ruby pumping beam. The conversion efficiency is about 80%. When the pumping beam is distorted by passing through an aberrant plate, the distorted wavefront is compensated.

Tunable coherent radiation in the infrared region of 2.78 to 3.25m has been obtained in Cs vapor by 6S~7S stimulated electronic Raman scattering (SEES) effect. The tunable infrared laser system developed is described, and the performances of the radiation are presented.

An inexpensive pulsed xenon ion laser with peak output power of about 10kW, pulse duration of 300 ns has been constructed and used as a pumping source for a tunable rhodamine 6G dye laser. 3-mirrors with astigmatism compensated cavity and grating-grazing incidence are used as the dye laser resonator and linewidth of less than 0.1 A is obtained. The dye laser is tunable from 5450~6200l with an total output of 1kW.

This paper describes a new technique in which a Nd3+: YAG laser is pumped by CW and pulsed light simultaneously. With compensation of thermal lensing effect, the laser can deliver laser light at low or high repetition rates with desirable stability and lifetime and the advantage of pumping by CW and pulsed light.

The construction features and performances of the dual-beam modlule (DBM) electron beam controlled laser are described. The specific output energy of 50m, efficiency of 10% and E/P of up to 8~9 kV/cm-atm have been achieved.

A totally sealed-off long-lifetime He-Ne laser made by metal glass is introduced. Its sturture is simple and reliable. The process can be mechanized, and can be put into large batch production with a qualified ratio of above 85%.

This paper describes the feature of higher energy conversion efficiency when a Nd:YAG laser medium is used for amplification. The energy conversion efficiency is higher. In general single rod Nd:YAG laser oscillators, the same laser rod is used both as oscillator and amplifier, thus the conversion efficiency is raised. It is especially obvious at low pumping energy. This is known as "the Composite technology.

An atmospheric pulsed N2 laser of eight channels is described and it generated a train of 8 VU light pulses. The duration of each pulse is whithin 1 ns and the time delay between pulses, 10~20ns.

Generation of synchronous ultra-short light pulses in a GaAs double heterostructurg laser excited by electrical pulses formed by a passively mode-locked and frequency-doubled Nd:YAG laser controlled opto-electronic switch is reported.

Experimental results on the movevements of an object surface and the speckle shift in the observation plane parallel to a direction normal to the object surface are reported.

Laser photo-acoustic technique has been used to measure the absorption coefficients of IR window materials (for example NaCl, KCl, AR-coated Ge, BaF2, CaF2 and ZnS) on R20, PSO (00?-02? transitions and 001-100 transitions) lines of CO2 laser. In this paper the above materials and their usage conditions have also been assessed.

This is a brief description of a pulsed ruby laser photographic system. It has the characteristics which make it an excellent source in a front lighted technique for obtaining photographs of models in flight. It may be used to measure the contours of models and its surface erosion and ablation during the flight.Photographs have been obtained of several models in flight at the velocity of ~1400m/s. These photographs .ealed details of the condition of model surfaces after launching and provided information which is not available from schlieren or shadowgraph method. Initial results indicate that this technique provides an excellent method for examination of high speed models in flight.