The Gaussian beam divergence for optical resonators (external divergence angle) is not equal to that in free space (internal divergence angle, as a definition) when the change of beam parameter through a dielectric interface has been considered. In this paper, using ABCD-matrix, g-and g*-parameterg, the formulae for external and internal divergence angles in fundamental mode operation and multimode operation have been derived analytically. Four typical examples have been compared and discussed: (l)optical resonators of solid-state lasers; (2) resonators with one plane mirror; (3) directly coated laser rods; (4) resonators with a thermal lens.

The damping of channeling radiation and the periodicity of crystal lattice field were considered. The motion equation of particles is simplified to the pendulum equation with weak damping and weak excitation. The chaotic behaviour of the system is discussed, Melnikov function in various cases is calculated, the threshold and possible approach to chaotic condition are derived.

A photoinitiated O2(1/1)-EI-N2 mixture has been made to lase with an output energy of over 160mJ. The utilization efficiency of the stored Oa(1) energy attains 12%. A comparison between O2C(1)-CHsI-Nj mixture and Oa(1)-CFal-N2 mixture suggests that the former exceeds the latter in many respects. It is also shown that Na is as good a buffer gas as AT in the oxygen-iodine laser with respect to the laser output.

Investigation of statical aberration in the phosphate glass disk amplifier with 100mm aperture by coaxial holographic method is reported. By COD, the reconstructed focus spot d is measured, from which, the effect of statical aberration on the divergence of laser beam is obtained.

Based on the diffiraction theory and Gaussian beam characters, the author derived an expression of beam magnification J1 of an afocal cylindrical lens. This expression modifies and expands Koichi Maseqi’s expression.

The construction, glow discharge stability and operation characteristics of high pressure long life-time sealed-off kW level transverse-flow COg lasers are reported. The effects of putting silica gel into the vacuum chamber, cooling the cavity region effectively and increasing pressure on the long-term sealed-off operation have been discussed.With gas flow velocity of 45m/s, gas mixture pressure of 82mmHg, active region length of 80cm, an output power of 1350W is obtained, with an electro-optic efficiency of 15.6% and CW operation time of over 30 hours.

By pumping an adjustable length ultrashort cavity Bh6G dye laser with a XeCl laser of a duration of 15-20ns, pulse compression of a factor of at least 15-20 ware achieved. Different [results on pulse width varing with the spot size and pumping laser energy were obtained.

The fluorescence spectra of Cr3+:YGG- crystals were studied at the temperatures ranging-from 10K to 300K with laser induced fluorescence method. The splitting of relevant fluorescence lines were measured, and the temperature dependance of the energy spacing between2T1, and2B, and 4Ta and 2E are derived.

The UV photodissociation of the C4H4N2, C4H4N2 and C6N4 molecules have been investigated. Laser-induced fluorescence (LIF) was used to study the nascent internal energy distribution of the ON radicals produced by photolysis of the above molecules at 193 nm. Tha 0-0 band rotational distributions of the X32+ state of CN radical can be described by a Boltzmann distribution foi all of these molecules. The rotational temperatures for v"=0 level of ON(X) are 1680+40, 2000+50 and 1470+30K for G4H4N2, C4H2N2 and G6N4, respectively. The rotational temperature of the 1-1 band is 1150+160K for C4H2N2 molecule. The gas phase UV absorption spectra of these molecules were measured.

This paper repots the thermostress birefringence induced by ps laser pulses in the glass plate, and the cause for this phenomena is discussed.

In this paper, we propose a speckle model for the diffusing object, considering the statistical nature of speckle phenomena, and the object illuminated with coherent light, the receding process of a specklegram is discussed and the formulae of specklegram are obtained. The formulae indicate that the frequency content ralates not only to the transform function of the imaging system, but also to the original frequency content of the diffusing object. Conclusions are confirmed by experiments. Then the formulae oftthe diffraction halo have been Seduced, which agree with the experiments well and can explain the speckle structure in the halo.

We demonstrated direct image transmission through a single multimode fiber by using the wavefront reversal properties of degenerate four-wave mixing in a photo-refractive crystal of 3Te:LiNb03 to compensate the image distortion caused by model dispersion in a fiber. The effect of phase conjugation on the state of polarization of the transmission image field ia discussed.

This paper describes the requirements for standard glass contact plank (SGCP) matched index liguid and the selection of SGCP glass material in precise measurement of glass blank homogeneity by means of holographic interferometry with SGCP.

This paper reports the synthesis of a negative photoresist, polypropanediol-(1, 3)-2-furylacroleinlidenemalonate (PPFM) and the change of photosensitization of PPFM to visible light when dye is appled. Experiments demonstrate that after photosensitivity is enhanced by methylenc blue and Wright’ s stain, PPF Mean be used aa relief phase holographic recording medium with He-Ne laser light.

The influences of fixing manner of the internal-mirror He-Ne laser on the direction drift of laser beam were investigated. The scheme of fixing output plane mirror was proposed which improves the direction drift of laser beam. Our experimental results show that the direction stability of laser beam can be increased using this method.

Ontput energy increase of over 40% from a XeCl laser have been obtained by increasing the spark numbers of UV preionization.

This paper presents the mode selection characters of the resonator with an output -coupling aperature in alexandrite lasers The experimental results are analyzed and discussed.

This paper reports a new light climbing effect in a thin sheet of crystal. The relevant optical properties have also been investigated.