Villeneuve ACHIH-CHUNG YANGStegeman G.IIronside C.N.2023-06-092023-06-09199400189197https://www.scopus.com/inward/record.uri?eid=2-s2.0-0028426445&doi=10.1109%2f3.303676&partnerID=40&md5=7555fdd48ea6cd5e72346e3757e317e0https://scholars.lib.ntu.edu.tw/handle/123456789/632158Nonlinear absorption in a GaAs waveguide is measured with photon energies near half the band-gap energy by employing single-beam and pump-probe attenuation techniques. Two-photon absorption followed by free-carrier absorption are the dominant nonlinear absorption mechanisms that are included in a model that fits the experimental data. © 1994 IEEEAttenuation; Charge carriers; Color centers; Electric losses; Electron absorption; Electron transitions; Energy gap; Photons; Refractive index; Semiconducting gallium arsenide; Solid state lasers; Ultrafast phenomena; Free carrier absorption; Gallium arsenide waveguide; Nonlinear photon absorption; Pump probe attenuation techniques; Single beam attenuation techniques; Optical waveguidesjournal article10.1109/3.3036762-s2.0-0028426445