Zinc Germanium Phosphide (ZnGeP2) is a highly regarded mid-infrared nonlinear crystal known for its exceptional properties. With a tetragonal crystal structure and a chemical formula of ZnGeP2, this crystal exhibits a significant nonlinear susceptibility, approximately 160 times larger than that of KDP (Potassium Dihydrogen Phosphate), with a d36 value of around 75 pm/V. This makes it an ideal choice for applications requiring efficient frequency conversion.

ZnGeP2 is celebrated for its broad optical transparency range, spanning from 0.74 to 12 micrometers. This wide range, combined with a high laser damage threshold, makes it particularly suited for producing near-infrared tunable lasers. The crystal's high thermal conductivity further enhances its performance, ensuring stability and efficiency in various optical applications.

The material's high nonlinear coefficient and phase-matching capabilities over a broad spectral region make it a promising candidate for mid-infrared devices, including second-harmonic generation (SHG), optical parametric oscillators (OPO), and optical parametric amplification (OPA). Its ability to maintain high performance under different conditions solidifies its role as a critical component in advanced optical systems.