Single TSAG Faraday Crystals Terbium Scandium Aluminum Garnet Iso9001

TSAG Faraday crystals

Terbium-scandium-aluminum garnet (TSAG) single crystal grown by the Czochralski method was annealed in a reducing or an oxidizing atmosphere. The oxidation state of terbium cations was studied using transmission spectra and magnetic susceptibility. By annealing in the reducing atmosphere, Tb4+ was reduced to Tb3+. In the case of annealing in the oxidizing atmosphere, some of Tb3+ ions were oxidized to Tb4+. Verdet constant and extinction ratios were measured after annealing in both atmospheres. The highest Verdet constant was obtained for the TSAG annealed in the reducing atmosphere (for λ = 649.1 nm V = 8.580 x 10-3 deg.Oe-1.cm-1). The extinction ratio of the sample annealed in the oxidizing atmosphere showed the highest value of 40.35 dB.

Features

• Verdet constant 20% higher than TGG

• Absorption 30% lower than TGG

Parameter

Application

Faraday isolator
Lasers with high average output power find application in different fields of activity: medicine, industry, space. They are actively used in numerous scientific projects such as ultrabright sources of radiation construction (ELI), inertial confinement fusion facilities (NIF, HiPER, Genbu), gravitational wave detection (LIGO, Virgo, Einstein Telescope) etc. The average output power of continuous wave and repetitively pulsed lasers is steadily growing, making it increasingly important to reduce thermal effects arising in various optical elements due to radiation absorption. Faraday isolators are essential parts of such laser systems as they prevent unwanted feedback and ensure safe operation of system.TSAG (terbium scandium aluminum garnet) crystal is interesting medium with effective Faraday rotation. Its advantage over the TGG crystal is a ~20% higher Verdet constant (the precise value depends on the content of scandium) and over the TAG crystal is the possibility of growing large-aperture single crystals of good optical quality.
Faraday isolator based on TSAG crystal for high power lasers
Imaging applications
Optical and scintillation properties of TSAG (Tb3Sc2Al3O12) crystal was investigated, and capabilities to be used as a scintillator screen was demonstrated. In photoluminescence (PL) spectra, some emission lines due to Tb3+ 4f-4f transitions appeared from 500 to 700 nm. PL quantum yields of TGG and TSAG were 6.5 and 50.9%, respectively. When irradiated by X-rays, these crystals showed intense scintillation, and the emission wavelengths were the same as those in PL spectra. The scintillation decay times of TSAG was 678 μs, respectively.Scintillation properties of TSAG crystal for imaging applications