Faraday Rotation of Dy2O3, CeF3 and Y3Fe5O12 at the Mid-Infrared Wavelengths

Faraday isolator based on crystalline silicon for 2-µm laser radiation

The magneto-optical properties of single-crystal silicon were investigated as a function of wavelength and temperature. A bulk free-space traditional Faraday isolator for the radiation with a wavelength of 1940 nm (magnetic field ∼2.8 Т) was implemented. The negative value of the piezo-optical anisotropy ratio of the used material allowed for the development of a Faraday isolator with compensation of thermally induced depolarization without a reciprocal rotator. The potential of single-crystal silicon as a magneto-optical material for Faraday isolators operating at room as well as at cryogenic temperatures in high-power laser radiation was considered. It was shown that single-crystal silicon is highly promising for the development of Faraday devices, including ones for next-generation laser interferometers aimed at detecting gravitational waves.

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. It was demonstrated experimentally that thermally induced depolarization is not expected at powers up to 2.5 kW.

Pressureless Sintering of YIG Ceramics from Coprecipitated Nanopowders

Nanoparticles prepared by the coprecipitation method were used as raw materials to fabricate Y3Fe5O12 (YIG) ceramics by air pressureless sintering. The synthesized YIG precursor was calcinated at 900–1100 °C for 4 h in air. The influences of the calcination temperature on the phase and morphology of the nanopowders were investigated in detail. The powders calcined at 1000–1100 °C retained the pure YIG phase. YIG ceramics were fabricated by sintering at 1200–1400 °C for 10 h, and its densification behavior was studied. YIG ceramics prepared by air sintering at 1250 °C from powders calcinated at 1000 °C have the highest in-line transmittance in the range of 1000-3000 nm. When the sintering temperature exceeds 1300 °C, the secondary phase appears in the YIG ceramics, which may be due to the loss of oxygen during the high-temperature sintering process, resulting in the conversion of Fe3+ into Fe2+.