title: Third order nonlinear optical property of Bi₂Se₃.
abstract: The third order nonlinear optical property of Bi₂Se₃, a kind of topological insulator (TI), has been investigated under femto-second laser excitation. The open and closed aperture Z-scan measurements were used to unambiguously distinguish the real and imaginary part of the third order optical nonlinearity of the TI. When excited at 800 nm, the TI exhibits saturable absorption with a saturation intensity of 10.12 GW/cm² and a modulation depth of 61.2%, and a giant nonlinear refractive index of 10⁻¹⁴ m²/W, almost six orders of magnitude larger than that of bulk dielectrics. This finding suggests that the TI:Bi₂Se₃ is indeed a promising nonlinear optical material and thus can find potential applications from passive laser mode locker to optical Kerr effect based photonic devices.
authors: Key Laboratory for Micro-/Nano-Optoelectronic Devices of Ministry of Education, College of Physics and Microelectronic Science, Hunan University, Changsha 410082, China.
authors: Shunbin
authors: S
authors: Lu
authors: Chujun
authors: C
authors: Zhao
authors: Yanhong
authors: Y
authors: Zou
authors: Shuqing
authors: S
authors: Chen
authors: Yu
authors: Y
authors: Chen
authors: Ying
authors: Y
authors: Li
authors: Han
authors: H
authors: Zhang
authors: Shuangchun
authors: S
authors: Wen
authors: Dingyuan
authors: D
authors: Tang
mesh_terms: D001729:Bismuth / Q000737:chemistry*; D007834:Lasers; D008422:Materials Testing; D017711:Nonlinear Dynamics; D012542:Scattering, Radiation; D012643:Selenium / Q000737:chemistry*
chemical_list: D012643:Selenium; D001729:Bismuth