Resonant and Nonresonant All-Optical Switching Devices in GaAs/GaAlAs

[摘要] The resonant refractive and absorptive optical nonlinearity of a GaAs/GaAlAs single quantum well waveguide are characterised; hh and Ih excitons are well resolved at room temperature. The unsaturated resonant nonlinear refractive index coefficient n2 was 1.4x10e-8 cm2/W, measured using the external Mach-Zehnder interferometric technique. It has been shown that the recovery time of the resonant nonlinearity is reduced to 125 ps (1/e recovery time), by placing the single quantum well close to the top surface. All-optical switching of an integrated asymmetric Mach-Zehnder interferometer is demonstrated and it was shown experimentally and theoretically that due to the absorption saturation, a complete switching is not possible. The nonresonant nonlinear optical properties of GaAlAs waveguide were characterised at photon energy below half the band gap.

[发布机构] University:University of Glasgow

[关键词] Electrical engineering, Condensed matter physics, Optics