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Tb3Al5O12 (TAG) ceramics with high optical quality were fabricated successfully by a solid‐state reaction method combined with hot isostatic pressing (HIP) post‐treatment. The microstructure, optical transmittance, Verdet constant, and thermo‐optical properties were investigated. The obtained TAG ceramics showed a dense microstructure, and the in‐line transmittance reached 82.8% at 1070 nm after laser‐grade polishing. The Verdet constant of TAG ceramics was measured to be 50.9 rad·T1·m−1 at 1070 nm, which is higher than that of commercial Tb3Ga5O12 crystals. The Faraday isolator based on TAG ceramics can provide an isolation ratio of 30 dB with a laser power of more than 1 kW. With excellent optical quality, high Verdet constant, and maximum working power, TAG transparent ceramics are promising for applications of kilowatt‐level Faraday isolators. [ABSTRACT FROM AUTHOR]

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. In the second pair, one of the cells, driven by a two-step voltage pulse, forms a giant pulse synchronized with the pulse of the first laser, and the other cell cuts a short pulse out of it. The proposed scheme allows a rather simple and reliable synchronization of two Q-switched lasers with a jitter of 150ps. OCIS codes: 140.3510, 140.3580.

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. Purpose-made experimental setup allows one to measure beams with an aperture of up to 60 mm with a spatial resolution of 1 mm. The accessibility of the utilized technologies and the possibility to easily increase the aperture are the major advantages of this approach. The probable area of application for the method is measurements of beams produced by powerful industrial far-IR lasers. OCIS codes: 040.3060, 140.6810, 120.3180.

The development and empirical analysis of Faraday rotators with short magneto-optical elements is given. It is found that the cooling the magneto-optical elements to nitrogen temperatures or by raising the magnetic field, elements can be reduced by three to four times which increases maximum average laser power passing through the Faraday isolators up to 50 kW.

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. OCIS codes: 120.5050, 120.3180, 120.6810.

A four-pass two-channel Nd:YAG laser having two amplifier rods in each channel was examined. Results showed that the laser configuration can compensate for aberrations and polarization distortions in Nd:YAG crystals of 15-mm diameter at a repetition rate of 25 Hz and can combine two channels of radiation into a single diffraction-limited beam. The energy of the laser output beam was found to be more than 5 joules.

Transparent ceramics based on ytterbium oxide have been successfully produced by vacuum sintering of self-propagating high-temperature synthesized powders with use of a La2O3 sintering aid. Phase composition and microstructure of the initial powders were studied by X-ray diffraction analysis and scanning electron microscopy. It was found that addition of 5 mol.% of La2O3 does not cause formation of secondary phases in the Yb2O3 powders. The 4% La:Yb2O3 ceramics showed the best in-line transmittance of 73% at a wavelength of 2 µm among the studied samples. Dependence of the Verdet constant on wavelength was investigated in the range of 0.4-2 µm. The most promising finding is use of the obtained material as Faraday isolators in the wavelength region of ~1.5 µm, where there are no absorption bands, and the Verdet constant is 8.6 rad/(T*m). [ABSTRACT FROM AUTHOR]

The magneto‐optical ceramics of terbium oxide doped with different rare earth elements (REE) REE:Tb2O3 (REE—Y3+, Lu3+, Sc3+, Ce3+, Dy3+, Ho3+, Yb3+, Nd3+) are successfully fabricated by hot pressing using powders obtained by the self‐propagating high‐temperature synthesis (SHS) method. The prepared REE:Tb2O3 ceramics have good optical quality and magneto‐optical properties. The in‐line transmittance of Tb2O3 ceramics doped with REE except Sc3+ is close to undoped terbium oxide, especially in the long‐wavelength region. The Verdet constant of the REE:Tb2O3 samples considered at 633 nm is about 3.3 and 2.6 times higher in absolute value than that of the commercial terbium–gallium garnet (TGG) single crystal and terbium–aluminum garnet (TAG) ceramics, respectively. It is noted that REE (except Yb3+ and Nd3+) doping only slightly increases the Verdet constant of pure Tb2O3 (when the content of terbium ions in the optical element is taken into consideration in the calculation). The dilution of the Tb2O3 matrix with REE in relatively high concentrations leads to a decrease in the absolute value of the Verdet constant. [ABSTRACT FROM AUTHOR]