Thermo-Optical Studies of Laser Ceramics.

A cycle of works on manufacturing and studying laser and magnetooptical ceramics with a focus on their thermo-optical characteristics performed by the research team is analyzed. Original results that have not been published before such as measurements of the Verdet constant in the Zr:TAG, Re:MgAlO, and ZnAlO ceramics are also presented.

High-purity CVD-ZnSe polycrystal as a magneto-active medium for a multikilowatt Faraday isolator.

Prospects for using ZnSe polycrystals synthesized by the chemical vapor deposition (CVD) method for the development of Faraday isolators for high-power radiation at a wavelength of 1076 nm are investigated. A Faraday isolator was built by a conventional scheme for room temperature operation. No thermally induced depolarization was observed in the device for the laser power range up to 1270 W, which is the main limiting factor for powerful isolators.

Matrix multi-pass scheme disk amplifier.

Two multi-pass optical schemes of a disk laser amplifier have been proposed. Different variants of both the schemes with the smallest amount of optical elements and a lens in the active element taken into account have been calculated. For 64 passes of radiation through the active element, the average power of ∼50  W with ∼10% optical-to-optical efficiency in a pulse-periodic regime with a repetition rate of 10 kHz and a pulse duration of 2 ns was obtained at the amplifier output.

Effect of full compensation of thermally induced depolarization in two nonidentical laser elements.

Thermally induced depolarization of radiation introduced by a system of two optical elements separated by a quartz rotator has been analyzed. The conditions of full compensation of thermally induced depolarization for two nonidentical optical elements have been found. The model experiment has demonstrated that full compensation in two optical elements of different materials is possible without a quartz rotator between them.

Self-compensation of thermally induced depolarization in CaF₂ and definite cubic single crystals.

Compensation of thermally induced depolarization in laser active elements at small birefringence without additional phase elements was proposed and observed experimentally. Requirements to the crystals were formulated. An order of magnitude reduction of depolarization degree was obtained experimentally.

Synchronization of two Q-switched lasers with 150 ps jitter.

Two Nd:YLF lasers with a pulse duration of about 2 ns have been synchronized. The duration and synchronization of two laser pulses are provided by two pairs of Pockels cells with synchronized voltage pulses. One of the Pockels cells in the first pair ensures Q switching, and the other cuts out a 2 ns pulse from the giant 20 ns pulse.

Interferometry based technique for intensity profile measurements of far IR beams.

We present a novel, to the best of our knowledge, method for measuring the intensity profile of far-IR beams. The method is based on the measurements of nonstationary variation in optical thickness of a fused-silica plate heated by the studied radiation. The optical thickness is observed by means of a reflecting interferometer.

High-precision methods and devices for in situ measurements of thermally induced aberrations in optical elements.

An optical system that comprises two devices for remote measurements, a broadband optical interferometer and a scanning Hartmann sensor, is described. The results of simultaneous measurements with both devices and the results of numerical modeling of sample surface heating are presented.