Progress in the design and synthesis of mid- and far-infrared nonlinear optical materials

February 06, 2024

Mid-far infrared (2–20 μm) second-order nonlinear optics (NLO) materials have important applications in photoelectric countermeasures, resource detection, space anti-missile, and communications. At present, the commercial mid-far infrared second-order NLO materials are AgGaS2 and ZnGeP2, but these two materials have some fatal weaknesses, such as low damage threshold and two-photon absorption. Therefore, exploring new mid- and far-infrared NLO materials is a difficult and hot spot in the current research of NLO materials.

With the support of the National Natural Science Foundation of China, the Chinese Academy of Sciences important direction project and other projects, the research team of Chen Ling, the Key Laboratory of Optoelectronic Materials Chemistry and Physics, Chinese Academy of Sciences, Fujian Institute of Material Structure has made a series of researches on the design and synthesis of mid-infrared infrared second-order NLO materials breakthrough. Innovatively put forward the academic ideas of nonlinear functional group assembly, ionic group control, and asymmetric control design of nonlinear functional group, obtained a series of mid-infrared second-order NLO materials with excellent performance, and found the strongest to date Kleinman-Forbidden powder frequency-doubling effect novel structure La4InSbS9 material, the compound is type I phase matching mid-far infrared NLO material, its powder frequency-doubling effect intensity reaches 1.5 times of commercial AgGaS2 material, the research results are published in "Journal of the American Chemical Society" (J. Am. Chem. Soc., 2012, 134, 1993–1995); Ba3AGa5Se10Cl2 (A = Cs, Rb, K) series materials were obtained by asymmetric control of the metal center of the nonlinear functional group, of which Ba3CsGa5Se10Cl2 material is At the size of 30-46μm, the frequency-doubling effect intensity of the powder is up to 100 times that of the commercial material AgGaS2. The research results are published in the Journal of the American Chemical Society (J. Am. Chem. Soc., 2012, 134, 2227–2235).

The discovery of these materials and the proposal of design ideas provide new ideas and directions for finding new mid- and far-infrared NLO materials.

Previously, the research team also made a series of progress in the research of novel structure NLO crystal materials, and found NLO crystal materials with good application prospects, such as: Ln4GaSbS9 (Ln = Pr, Nd, Sm, Gd–Ho) (J. Am. Chem. Soc., 2011, 133, 4617–4624), Pb2B5O9I (J. Am. Chem. Soc., 2010, 132, 12788–12789), La2Ga2GeS8 and Eu2Ga2GeS7 (Inorg. Chem., 2011, 50, 12402 –12404) etc.