Laser-induced damage of garnet films grown by LPE

Abstract

Laser-induced damage of magneto-optical (MO) materials is a key factor that limits the application of optical isolators in high-power laser systems. In order to investigate parameters that affecting laser-induced damage thresholds (LIDT) of MO garnet films grown by liquid-phase epitaxial (LPE) method, YIG, (LuBi)3Fe5O12 and (BiTm)3(GaFe)5O12 single crystal films with small lattice mismatch were prepared in this study. The transmittance, optical absorption coefficient, crystal structures, surface quality and laser-induced damage thresholds (LIDT) of the prepared three kinds of MO films were investigated. Microstructure analysis shows that single crystal garnet films grown by LPE method have high surface and crystal quality. Laser-induced damage tests (@1064 nm, 11 ns) pointed out that LIDT of YIG, (LuBi)3Fe5O12 and (BiTm)3(GaFe)5O12 films are 6.41 ± 0.18 J/cm2, 6.32 ± 0.25 J/cm2 and 4.11 ± 0.27 J/cm2, respectively, and intrinsic optical absorption coefficient of single crystal garnet films plays a decisive role in their laser-induced damage.