Recent Advances in Infrared Nonlinear Optical Crystal

The search and growth of nonlinear optical (NLO) crystals in the infrared (IR) area are significant and of high importance in the fields of NLO, signal communication, solid-state chemistry, and laser frequency conversion. Infrared NLO crystals have a wide IR transparent range, high laser damage threshold (LDT) value, and large NLO coefficients. This chapter presents the recent advances in IR-NLO crystals and especially emphasizes their crystal growth method, crystal structures, band gap value, LDT, and NLO properties. Based on its structural variety, it is categorized into chalcogenides, chalcohalides, oxides, halides, and oxyhalides. This chapter describes several kinds of IR-NLO crystals and their structural, band gap value, thermal, optical, LDT, and NLO properties and also describes the significance of these crystals in laser frequency conversion, optical parameter oscillator, and other optical applications.