title: Nonlinear absorption and nonlinear refraction in a chemical vapor deposition-grown, ultrathin hexagonal boron nitride film.
abstract: An ultrathin hexagonal boron nitride film is synthesized by a method of chemical vapor deposition. Irradiated by femtosecond laser pulses in the visible spectrum of 400-800 nm, it exhibits multiphoton absorption and positive nonlinear refraction properties. The two-photon and three-photon absorption coefficients are of the order of 10-5cm W-1and 10-14cm3W-2, respectively. The nonlinear refraction coefficient is as large as ∼10-8cm2W-1. These nonlinear coefficients lead to figures of merit that meet the material requirements for all-optical switching devices.
authors.forename: Qiuyun
authors.initials: Q
authors.lastname: Ouyang
authors.forename: Kai
authors.initials: K
authors.lastname: Zhang
authors.forename: Weiqiang
authors.initials: W
authors.lastname: Chen
authors.forename: Feng
authors.initials: F
authors.lastname: Zhou
authors.forename: Wei
authors.initials: W
authors.lastname: Ji