We have investigated experimentally the linear and cubic nonlinear properties of multimode waveguides fabricated on AlGaAs wafers. By varying the input beam position or angle of incidence, the multipeak intensity profiles observed at the waveguide output unveil clearly the multimode nature of the waveguide. Because of the large Kerr nonlinearity of the semiconductor, the field evolution inside the waveguides depends on the launched intensity. Numerical simulations have confirmed the experimental findings and an analytical model, based on the nonlinear interaction between the modes of the dielectric structure, explains the device behavior and clarifies the role of the injected beam parameters.
© 2005 Optical Society of America
Daniele Modotto, Costantino De Angelis, Marco A. Magaña-Cervantes, Richard M. De La Rue, Roberto Morandotti, Stefan Linden, Henry M. van Driel, and J. Stewart Aitchison, "From linear to cubic nonlinear imaging effects in multimode waveguides," J. Opt. Soc. Am. B 22, 870-877 (2005)