title: Measurement of nonlinear refractive index coefficient using emission spectrum of filament induced by gigawatt-femtosecond pulse in BK7 glass.
abstract: A beam of 33 fs laser pulse with peak power of 15-40 GW was employed to explore a convenient method to determine the nonlinear refractive index coefficient of an optical glass. It is rare to investigate nonlinearities of optical glass with such an extreme ultrashort and powerful laser pulse. According to our method, only a single beam and a few experimental apparatuses are necessary to measure the nonlinear refractive index coefficient. The results from our method are in reasonable agreement with the others, which demonstrates that this new method works well, and the nonlinear refractive index coefficient is independent of measuring technology. Meanwhile, according to our results and those obtained by others in different laser power ranges, it seems that the nonlinear refractive index coefficient has a weak dependence on the laser peak power.
authors.affiliation: School of Nuclear Science and Technology, Lanzhou University, Lanzhou, Gansu, China.
authors.forename: Xing
authors.initials: X
authors.lastname: Lu
authors.forename: Qingcao
authors.initials: Q
authors.lastname: Liu
authors.forename: Zuoye
authors.initials: Z
authors.lastname: Liu
authors.forename: Shaohua
authors.initials: S
authors.lastname: Sun
authors.forename: Pengji
authors.initials: P
authors.lastname: Ding
authors.forename: Baowei
authors.initials: B
authors.lastname: Ding
authors.forename: Bitao
authors.initials: B
authors.lastname: Hu