The importance, fundamental principles and methods of tuning optical cavity for free-electron lases are described. An adjustable mechanical device controlled by a microcomputer is used for adjusting with a fine resolution., and an electro-strictive device iontrolled by the same microcomputer is used for adjusting with superfine resolution. The fine adjusting range is 6cm, and the resolution is better than 0.5μm. The superfine adjusting range is 10μm, and the resolution is better than 0.1μm.

Optical holographic interferometry has shown remarkable advantages in the vibration analysis of loudspeakers. Taking the vabration testing of the loudspeakers as an example, this paper describes the principle and the method of testing, introduces a portable holographic camera used for the testing. Some experimental results are presented.

This paper presents the principle and the method of vibration measurements by means of laser-CCD microdisplacomcnt sensors.This measurement technique can be applied for larger amplitudes (>60 μm). In 60~800 μm range, the absolute maximum error is <10 μm, and the relative error <6%.

Some formulas of phase retardation of any light passing through a Wollaston prism are given and the distribution of retardation in a special convergent beam is analysed.

In this paper, we pressnt the results of colliding pulse mode-looking of (Ce3+, Nd3+):YAG lasar using an antiresonant ring in the unstable resonator. Using a(Ce3+, Nd3+): YAG laser crystal of 3×40 mm insizs and the pentanethine oyanine in 1, 2-dichloethane, 3.2 mJ output energy with 9ps pulse width has been obtained.

A comparative experimental study results are reported in this paper in 125 wisiar rats to small artery and carotid common veins anastomoses between low power CO2 laser welding and traditional hand suture.

The study of irradiation in streptomyces aureof aciens with copper yapor lasar is reported. High yield strain with laser breeding of S. aureofaeiens is also obtained, which increases the unit of fermentation by about 12% than that of control group.

He-Ne laser (35mW) irradiation on Syrian hamster embryo flbroblast cells in Titro cultures directly induced malignant transformation. He-Ne laser transformed cells elicited fibrosarcomas ia BALB/c-nu/nu mice and have aneuploid karyotypes.

CO2 laser beam was used to sinter green compacts made of alloy powder. Elements were analyzed using EDS and X-ray diffractometer. It was found that the element diffusion occourred during the laser sintering, forming refined Fe3G and CuMO2S5-a phases. Green compaets with a diameter of 10 mm can be fully sintered within omin.

An experimental research on dye oscillator-amplifier configuration pumped by CVL is described. The characteristics of the dye laser, such as bandwidth, output power, efficiency, pulse duration, tuning range, spectral purity and frequency stability etc, are measured in details. 6.7 W output power has been obtained from the Eh6G dye laser.

Laser gain(λ=632.8 nm, transition 3S2-2P4)of 3He-Ne laser system (PHe:PNe=5:1,Ptotal=4×104 Pa) radiated by thermal neutron from steady operation reactor is measured. The measured gain coefficient is 1.7×10-2/em at thermal nuetron flux of 2×1012 n/cm2-s-Gain curve vs flux of thermal neutron is investigated. The influence of temperature on gain is discussed. The test shows the possibility of lasing from nuclear-pumped 3He- Ne laser system.

Laser output curves and a threshold curve of a fast-axial-flow CO2 laser excited by RP were measured at different dimensions of laser discharge tubes, different parameters of the optical cavity, different prr ssures of CO2 mixture gases and different volume pumping velocities of the blower, respectively. The optimal ratio of CO2 mixture gase was obtained. The experimental results were compared with laser output of the same experimental apparatus excited by DC.

We reported hero in the experimental results of pulse repetitive and CW laser of La1-xMgNdxAl11O19 crystals at 300 K.

The formulas of the forces applied by a TEM00 Gaussian laser beam on the transparent spheres are derived under the apporximation of geometric optics with regard for the contraction of a strongly focussed Gaussian optical beam. The numerical results show the condition of the laser trapping of a single lassr beam. The effects of the absorption of light on the trapping are also discussed.

The calculation method 01 angle phaae-matching for optical parametric generation (OPG) in biaxial crystals was presented. The angle phase-matching curves and their characteristics of OPG in KTP crystal pumped by 355nm, 532nm, and 1064nm radiation were calculated and analyzed. Our experimenis have confirmed the optical parametric generation pumped by 532nm laser output, which is in agreement with the calculated curves for angle phase-matching of type II in X-Z plane.

By means of extended average level model of relativistio multieonfiguration Dirac-Fock (MCDF-EAL) code, we have calculated fine-structure energy levels of 2s22p5,232p6, 2s22p43s, 2s22p43p configurations and some transition wavelengths of 3s-3p for F-like ions of 21≤Z≤26, which may be the condidates for lasing action. Some energy levels of 3p configuration and transition wavelengths of 3s-3p are predicted.

The paper reports the measurement of 78 high-lying levels in samarium atoms by two-colour three-photon resonant ionization. These newly measured levels of even parity belong to 4/66s7S configuration and located in the energy range between 33477 and 37758 cm-1.

This paper firstly reports the operation and characteristics of a completely sealed BN waveguide CO2 laser with an operating time of over four hundred hours.

Thia paper presents a demountable double-pulse TEA CO2 laser. It has the advantages of stable function, lower price, compact construction, and it is convenient to demount and adjust.

A new nonlinear optical material ZnS·BaSO4 is first reported.It generates second-harmonic radiation with a powder efficiency of about one thousand times that of KDP. The structural properties of this material has been studied by electron diffraction.