Characterization and properties of novel infrared nonlinear optical crystal CsGe...

Innovative infrared nonlinear optical crystals CsGe(BrxCl(1-x))3 were synthesized. Their powder X-ray diffraction patterns indicated that they had rhombohedral structures with (R3m, No. 160) space group symmetry. Their structural distortion increased with x. The Kurtz powder techniques revealed that the nonlinear optical efficiency of CsGeBr3 is about 9.64 times larger than that of rhombohedral CsGeCl3 and 28.29 times larger than that of KH2PO4 (KDP); most importantly, CsGe(BrxCl(1-x))3 is phase-matchable. The transparent infrared spectrum of rhombohedral CsGe(BrxCl(1-x))3 was extended to over 30 mum and demonstrated its potential in the field of nonlinear optics and applicability in the infrared region.