# Lithium gallium sulfide, LiGaS2 (LGS)

Lithium gallium sulfide (LiGaS2, abbreviated as LGS) is a nonlinear optical crystal material often employed in frequency conversion applications, including second harmonic generation and optical parametric oscillation. Its broad transparency range in the infrared spectrum and high nonlinearity make it suitable for laser systems and other photonics applications. Like other nonlinear optical materials, LGS needs to be phase-matched for effective frequency conversion, and its optical properties can vary with temperature and orientation. Special care must be taken in handling and storing the crystal to prevent degradation of its optical qualities.