Optical Nonlinearity in Cu2CdSnS4 and α/β-Cu2ZnSiS4: Diamond-like Semiconductors with High Laser-Damage Thresholds
journal contributionposted on 04.08.2014, 00:00 by Kimberly A. Rosmus, Jacilynn A. Brant, Stephen D. Wisneski, Daniel J. Clark, Yong Soo Kim, Joon I. Jang, Carl D. Brunetta, Jian-Han Zhang, Matthew N. Srnec, Jennifer A. Aitken
Cu2CdSnS4 and α/β-Cu2ZnSiS4 meet several criteria for promising nonlinear optical materials for use in the infrared (IR) region. Both are air-stable, crystallize in noncentrosymmetric space groups, and possess high thermal stabilities. Cu2CdSnS4 and α/β-Cu2ZnSiS4 display wide ranges of optical transparency, 1.4–25 and 0.7–25 μm, respectively, and have relatively large second-order nonlinearity as well as phase matchability for wide regions in the IR. The laser-damage threshold (LDT) for Cu2CdSnS4 is 0.2 GW/cm2, whereas α/β-Cu2ZnSiS4 has a LDT of 2.0 GW/cm2 for picosecond near-IR excitation. Both compounds also exhibit efficient third-order nonlinearity. Electronic structure calculations provide insight into the variation in properties.