Growth and Properties of TSAG Crystal

doi:10.16553/j.cnki.issn1000-985x.2026.0114

Abstract

Abstract: Terbium scandium aluminum garnet （Tb₃Sc₂Al₃O₁₂， TSAG） crystal is a novel magneto-optic crystal with outstanding magneto-optical properties， which holds great promise for wide applications in high-power lasers. However， the high stress and susceptibility of TSAG crystal to cracking restrict the processing and practical utilization of corresponding optical components. To improve the crystal quality， this paper focused on the high stress problem in TSAG crystal and systematically investigated the composition distribution along the crystal growth direction and radial direction. By optimizing the crystal growth process， the composition uniformity of TSAG crystal was effectively enhanced， and ?45 mm×100 mm low-stress TSAG crystal was successfully grown. The fabricated TSAG crystal component exhibits an absorption loss coefficient of 0.19%/cm， and the developed isolator with a 3 mm clear aperture achieves a minimum isolation of 36.19 dB. The magneto-optical properties of TSAG crystals in different directions are further studied in detail. The crystal in the ［100］ direction possesses the maximum Verdet constant （51.38 rad·m^-1·T^-1）， which is beneficial for the miniaturization of isolators. The research results demonstrate that the successful development of low-stress TSAG crystal is expected to realize the application of TSAG crystal in high-power laser system.

Key words: magneto-optical crystal; TSAG crystal; crystal growth; composition distribution; isolation device; magneto-optical property

CLC Number:

DOU Renqin, YANG Mingliang, WANG Xiaofei, WANG Xinyu, LIU Wenpeng, GAO Jinyun, LUO Jianqiao, ZHANG Qingli. Growth and Properties of TSAG Crystal[J]. Journal of Synthetic Crystals, 2026, 55(9): 1357-1362.

Figures/Tables 7

Fig.1 Photograph of as-grown TSAG crystal

Fig.2 Schematic diagram of sample positions for component testing

Fig.3 Composition distribution along growth direction of cracked TSAG crystal

Fig.4 Composition distribution along radial direction of cracked TSAG crystal

Fig.5 Stress distribution of TSAG crystal. （a） After optimization of growth process；（b） before optimization of growth process

Table 1 Verdet constants in different directions of TSAG and TGG crystals at 1 064 nm wavelength

Crystal	Verdet constant/（rad·m^-1·T^-1）
Crystal	［111］	［110］	［100］
TSAG	48.79	48.32	51.38
TGG	37.66	37.18	40.49
TSAG^［17］	49.8
TGG^［23］	40.5

Fig.6 Schematic diagram of TSAG isolator

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