Very sensitive two-photon absorption GaAs/AlGaAs waveguide detector for an autocorrelator

Abstract
Two-photon-induced conductivity (TPC) in a reverse biased pin GaAs/AlGaAs optical waveguide is observed, and the intensity-dependence of the photocurrent characterised. When this waveguide was used as the nonlinear detection element of an autocorrelator, an autocorrelation trace of a CW mode-locked Nd3+: YAG laser at 1.06 μm was successfully obtained.