A simple method to determine the lifetimes of excited saltes of atoms by two-step excitation with long laser pulses is presented. Based on a four-level model, the lifetimes are obtained by computer-aided analog between experimental results and theoretically calculated curves, and in agreement with those obtained by other methods.

The diffraction-free beam produced by an axicon has constant size and intensity distributions. Therefore it could be exploited for practical use in many areas. The diffraction-free beam and its properties were introduced in this paper. Finally, the designing method of a binary axicon and computer based simulation results are presented.

It is reported that a double-solenoid pulsed valve with pulse width less than 200 μs has operated successfully. The peak intensity of the produced gas pulse is about 2×1022 molecules/sr.s without Skimmer. The main features of the valve are comparable with those used in foreign representative laboratories for the generation of cluster beams with laser vaporization/molecular beam technique.

Request for laser characteristics of keratoplastic surgery is described. It is reported that RK and PRK experimental studies of animals eyes using an ArF excimer laser manufactured on our own are performed.

Influence of He-Ne laser analgesia on physiological function of horses was estimated by analysing the parameters such as cardiac function, blood gas and electroencephalogram. The results provided new basis for choosing analgesic method in veterinary practice and studying the mechanism of He-Ne laser analgesia.

This paper presents experimental studies in which the drying corn seeds are irradiatedby He-Ne laser at power densities of 2.8 mW/mm2,3.8 mW/mm2 and 5.4 mW/mm2, respectively, and the corresponding irradiating times last 5 s, 50 s and 500 s. As a result, the POD and CAT activities of corn seedling are enhenced while their AsAPOD activity is reduced and their GSH contents are increased. Consequently, the improvement of the active oxygen metabolism for plants the seeds of which have been irradiated can be expected.

Studies of formation of titanium nitride layer with laser gas alloying by multipulse laser irradiation of 5-ns duration are described. The nitridation process was observed by detecting the light emitted above the surface while it is irradiated. The nitrided surface was morphology-examined by an optical microscope and a scanning electron microscopy (SEM) and characterized by time of light mass spectrum (TOFMS) during laser ablation of the surface as well as by X-ray diffraction (XRD). The laser pulses melt the titanium surface and activate N2, which leads to nitridation of titanium in liquid phase. It is also found that the nitride layer grown is rich in Ti and consists of δ-TiN and α—Ti.

Shlomo Pinhas proposed a wiggler in which magnetic field is independent of axial coordinate. The angular spectrum of spontaneous emission in this kind of wiggler is calculated by means of Madey's theorem in this paper. By comparing the result with that of the ordinary linearly polarized FEL, we find that they have identical forms. It is shown that a FEL operation is possible in this wiggler by using higher harmonics.

A phase-locking approach of CO2 waveguide laser array is proposed. As a result, a new type CO2 waveguide array laser is developed. The near-field laser intensity distribution and far-field symmetrical and unsymmetrical mode field distributions are observed.

Over a frequency range of 200 MHz～1500 MHz～2000 MHz, the side-light spectrum of helium microwave discharge and the dependence of small signal gain at 632.8 nm on excited frequency were measured. The microwave excited frequency characteristics of a He-Ne laser has been investigated.

The properties of Nd:YVO4 solid-state laser pumped with a Ti:sapphire laser have been investigated. The output power of 190 mW and the pump threshold of 13 mW have been obtained where the optical slope efficiency was 51%. The output power of 10 mW for the second-harmonic light was observed using an intracavity KTP crystal, and the total optical efficiency was 2.3%. The dependence of the output power on the pump wavelength ranging from 740 nm to 830 nm is given.

Passive Q-switched laser has been achieved in Nd:YAG transversely pumped by a Q-CW 60 W laser-diode-array. While the laser diode was working on a repetition rate of 10 Hz at power as high as 60 W and pulse width of 400 μs, a free running stable oscillation with output energy of 3 mJ was obtained. Making use of a LiF:F2-crystal as a saturable absorber, Q-switching operation was succeeded. There were three multiple-transverse-mode pulses with energy of 400 μJ and width of 11.5 ns for every individual pulse within per period. Some suggestions are presented here in order to obtain highly efficient single pulse with single-transverse-mode.

A high efficiency Ti:Sapphire laser system consisted of a Littman configuration oscillator and one stage single pass amplifier is presented. While the pumping source (532 nm Nd:YAG) energy is 140 mJ/pulse, the SLM (single longitudinal mode) output of the system reaches 22.5 mJ in the vicinity of 800 nm. The conversion efficiency is about 16%. In addition, the amplification characteristics of the Ti:Sapphire and the focusing positions of the pump laser are discussed.

Codoped Nd3+ ion improved the quality of Cr:ZnWO4 single crystal and raised its lasing efficiency. Laser pulse at wavelength 0.95 μm was generated with a 6 mm diameter, 19 mm long rod, which was pumped with a ruby laser The maximum output energy is 1.62 mJ and the slop efficiency is 0.79%.

An analysis is given of the propagation characteristics of Gaussian beams for solid-state slab geometry lasers with astigmatism compensated or not. A method of compensating the astigmatism of the solid-state slab geometry laser is described.

A co-pumped Erbium-Doped Fiber Amplifier (EDFA) which consists of home-made 1480 nm pigitaled LD's and erbium doped fiber (EDF) has been developed. A small-signal gain of 32 dB of the EDFA has been obtained (fiber to fiber net gain is 27 dB). The saturation power and maximum power of fiber are 2.5 dBm and 10 dBm, respectively, while the gain bandwidth is greater than 25 nm.The gain and bandwidth characteristics of the EDFA are studied. Effects of Amplified Spontenous Emission (ASE) on measurement are discussed.

In this paper, the Er3+-doped optical fiber amplifiers (EDFA's) have been investigated experimentally, which are pumped by LDs at wavelengths of 1.45 μm and 1.47 μm. The results show that the signal light can also be amplified by the EDFA pumped at wavelength of 1.45 μm. A gain of 27 dB has been obtained for the EDFA's forwards and backwards pumped at wavelengths of 1.45 μm and 1.47 μm.

The accumulation effect of repeat-rate-laser induced damage in optical coatings is experimently investigeted. The mechanism of accumulation damage is discussed. Steps to enhance damage threshold of the optical coatings are taken and some experimental results are shown.