V. V. Lobachev

Regular and stochastic small-scale phase heterogeneities of gas lasers active medium and their influence on optical resonator efficiency

The specific features of the unstable optical resonator of a large gas laser with an active medium containing regular and stochastic phase inhomogeneities are considered. The output power of the laser, the Strehl number, the angular divergence and average far-field intensity are described as function of the spatial scale and structure of inhomogeneities of the refractive index of the active medium.

Optical beam quality of COIL

The questions of optical beam quality of COIL are considered. The classification and meanings of different type of optical aberrations in COIL is presented. The ways of compensation of amplitude aberration by structure-parametrical optimization of the unstable resonator are offered. The scheme of automatically resonator alignment for compensation of phase aberrations originated from misalignment is presented. The 3D numerical modeling and investigation of gas flow and chemical kinetic in COIL is fulfilled. The scales and magnitude phase aberrations coimected with gas flow non-homogeneities are analyzed. The optimization of the COIL nozzle bank length from point of view of maximal beam brightness is fulfilled.

Compensating for birefringence in cylindrical active elements of solid-body lasers

We discuss a new method of compensation of thermally induced birefringence in cylindrical active elements of solid-body lasers; the method is based on the simultaneous use of two active elements with sign-opposite temperature gradients in the transverse direction. Basic features of the method are shown and schemes of its practical implementation are considered.

Depolarization loss of interference-pattern contrast when probing radially loaded cylindrical glass laser matrices

Results of an investigation of the depolarization loss of interference-field contrast are presented. The loss of contrast was found experimentally and simulated numerically for different interferometric schemes: with lateral and radial shifts and with a reference beam. It is found that the original polarization of the probing radiation affects substantially the integral contrast of the interference field.

SPECIAL FEATURES OF THE INTERFEROMETRY OF RADIALLY LOADED LARGE GLASS LASER MATRICES

We present the results of computational investigation of the loss in contrast of interference patterns of lateral shear with a reference beam. We consider the behavior of the degree of coherence over the active element cross-section and in time after starting the laser pumping system in operation, as well as the behavior of the integral degree of probing-radiation depolarization.

PECULIARITIES OF LINEAR SCALING OF CYLINDRICAL GLASS ACTIVE ELEMENTS OF SOLID-STATE LASERS

Optimization of the glass cylindrical active element (AE) of a solid-state laser is carried out. Dependences of the optical quality of a laser medium on scale-geometry parameters of the AE with different-intensity optical pumping are obtained. The possibility of considerable increasing of the laser efficiency by using an aperture diaphragm is shown.