Anisotropy of nonlinear optical properties in monoclinic Sm^sub x^Y^sub 1-x^Ca^sub 4^O(BO^sub 3^)^sub 3^ crystals

• Published in: Journal of alloys and compounds Vol. 762; p. 431
• Main Authors: Liu, Yanqing, Yu, Fapeng, Wang, Zhengping, Yang, Xiuqin, Han, Shuo, Xu, Xinguang, Zhao, Xian
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier BV 25.09.2018
• Subjects: Anisotropy; Crystallography; Crystals; Nonlinear optics; Optical properties; Phase matching; Phase transitions; Rare earth elements; Samarium; Sapphire; Yttrium
• ISSN: 0925-8388; 1873-4669

The angular noncritical phase matching (A-NCPM) second-harmonic-generation (SHG) properties of SmxY1-xCOB (x = 0, 0.44, 0.55 and 1) nonlinear optical (NLO) crystals were investigated. The type-I A-NCPM SHG wavelengths along the Y and Z axes were found to be tunable in the ranges of 725–900 nm and 826–1116 nm, respectively, by adjusting the ratio of the rare-earth elements Sm and Y in SmxY1-xCOB crystals. Taking advantages of the fundamental laser pulses generated from a mode-locked Ti:Sapphire laser and a long Y-cut Sm0.44Y0.55COB crystal sample, the single-pass SHG average output power of ∼436 mW at 397 nm was obtained with a conversion efficiency of 41.5%. In addition, the SHG phase-matching (PM) curve and the effective NLO coefficients (deff) of SmCOB crystal for 1064 nm laser were studied, where the optimal type-I SHG PM direction in principal planes was determined to exist in the XY principal plane i.e. (90°, 52.4°), rather than the ZX plane i.e. (θº, 180°), which was different with those of TmCOB (32.5°, 180°), YCOB (30.7°, 180°), TbCOB (22.6°, 180°), GdCOB (19.7°, 180°) and LaCOB (15.1°, 180°) crystals in the same crystal family.