Large nonlinear optical properties of an InGaAs/InAlAs multiple quantum well waveguide for 1.55 µm

Much attention has been paid to an enhanced third-order optical nonlinearity in semiconductors by the quantum size effect.1 Their large nonlinearities can be applied to all-optical signal processing, such as self-routing in optical communication networks. However, much less work has been reported on the MQWs in the 1.5– 1.6-μm wavelength region.2 Here, we demonstrate for the first time a drastic phase shift > 4π in a 1.55-μm InGaAs/InAlAs MQW waveguide with as much as 25 mW of a pulsed pump light.