Thermo-optical properties of cryogenically cooled (Tb0.9Y0.1)2O3 ceramics

• DOI: 10.1016/j.optcom.2021.127508
• Publication Date: 2021-09-30T17:15:27Z
• Authors: A. Yakovlev; I. Snetkov; O. Palashov
• Keywords: Optical Isolator; Verdet constant; Atmospheric temperature range; Terbium

Abstract Due to a high Verdet constant and paramagnetic properties, the ceramics based on terbium oxide is a promising candidate as a magneto-optical medium for developing cryogenic Faraday isolators. Cryogenic cooling suppresses thermal effects and leads to an increase in the maximum power of the laser radiation passing through the Faraday isolator at the same isolation ratio. We have measured the thermally-induced depolarization and the thermal lens within the 81–297 K temperature range and the linear absorption coefficient α 0 within the 83–297 K temperature range in (Tb 0.9 Y 0.1 )2O3. The ratio of the effective thermo-optical constants P e f f / Q e f f was ∼ 6.44 in the studied temperature region. On cooling to LN2 temperature, the parameters α 0 Q e f f / κ and α 0 P e f f / κ ( κ is the thermal conductivity coefficient) decreased by a factor of ∼ 5.2. The α 0 was temperature independent. The results of the study demonstrate great prospects for the use of terbium oxide based ceramics in cryogenic Faraday isolators.