title: Multiphoton absorption and nonlinear refraction of GaAs in the mid-infrared.
abstract: We report the wavelength dependencies of the two- and three-photon absorption coefficients of undoped GaAs in the spectral range 1.3-3.5 microm, as well as nonlinear refractive index n2 in the range 1.7-3.25 microm. The data were obtained by using the single-beam Z-scan method with 100-fs-long optical pulses. Anisotropy of the three-photon absorption coefficient was observed and found to be consistent with the crystal symmetry of GaAs.
authors.affiliation: Department of Physics, Oregon State University, Corvallis 97331-6507, USA.
authors.forename: W C
authors.initials: WC
authors.lastname: Hurlbut
authors.forename: Yun-Shik
authors.initials: YS
authors.lastname: Lee
authors.forename: K L
authors.initials: KL
authors.lastname: Vodopyanov
authors.forename: P S
authors.initials: PS
authors.lastname: Kuo
authors.forename: M M
authors.initials: MM
authors.lastname: Fejer