Abstract

Since the early days of nonlinear integrated optics, there has been a lot of interest in studying the propagation of light in media with nonuniform nonlinearities. In these early papers, the cladding, substrate, and waveguide layers were either linear or nonlinear. These highly nonlinear waveguides work because of the change in the shape of the held caused by the nonlinearity By contrast, most of ultrafast alloptical switching devices rely on an accumulated nonlinear phase shift for their operation rather than on abrupt variation in nonlinearity. Recent work on disordering of multiple quantum wells (MQW) has shown that the nonlinearity of the MQW layer can be reduced by as much as 60%.¹ This novel impurity free vacancy disordering technique can be discretely applied by use of a mask, in a process similar to photolithography, so the nonlinearity of the MQW layer can he locally suppressed. This result makes the observation of highly nonlinear waveguide phenomena possible in AlGaAs with photon energies below half the band gap.

© 1997 Optical Society of America