Two-photon absorption in In1−<i>x</i>−<i>y</i>Ga<i>x</i>Al<i>y</i>As/InP waveguides at communications wavelengths

Abstract

We have observed and measured two-photon absorption in In1−x−yGaxAlyAs/InP waveguides grown by molecular beam epitaxy over the wavelength range of 1.5–1.65 μm. The values of β2, the two-photon absorption coefficient, were 63 and 20 cm/GW for waveguides of compositions x=0.32, y=0.17 and x=0.15, y=0.31, respectively. These values are comparable with those predicted by scaling laws. We estimate the associated nonlinear refractive index coefficient n2 and discuss the implications for all-optical switching.