This invention relates to a
germanium-based chiral
perovskite second-order
nonlinear optical crystalline material, its preparation and application, wherein the
chemical formula of the material is ( R -C7H 10 NO)GeI3 and ( S -C7H 10 NO)GeI3, where R -C7H 10 NO is a (R)-2-(1-hydroxyethyl)
pyridine cation. S -C7H 10 NO is a (S)-2-(1-hydroxyethyl)
pyridine cation. This
crystal belongs to the
hexagonal crystal system,
space group [
space group number missing]. P 63,
cell parameters a =17.0~18.0 Å, b =17.0~18.0 Å, c =7.0~8.0 Å, unit
cell volume V =2000~2200 Å 3 , α = β =90°, gamma =120° Z= 2. Under 1200 nm
laser irradiation, the
nonlinear optical crystal of the present invention ( R -C7H 10 NO)GeI3 and ( S -C7H 10 The frequency doubling effect of GeI3
powder is 15 times that of KH2PO4; under 2000 nm
laser irradiation, the frequency doubling effect of the crystalline material
powder is 1.0 times that of KTiOPO4, and both can achieve
phase matching. The crystalline material also has a large
birefringence, wherein ( R -C7H 10 NO)GeI3 is 0.518 @ 546 nm, ( S -C7H 10 The NO)GeI3 has a
wavelength of 0.529 nm at 546 nm and a moderate optical
band gap (2.68 eV). The crystalline material of this invention shows significant
engineering application value in
nonlinear optical applications such as near-
infrared laser frequency conversion, optical parametric amplification, and electro-optic
signal processing.