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

Al-Hemyari, Kadhair A (1992) Resonant and Nonresonant All-Optical Switching Devices in GaAs/GaAlAs. PhD thesis, University of Glasgow.

Abstract

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.

• Item Type: Thesis (PhD)
• Qualification Level: Doctoral
• Additional Information: Adviser: C N Ironside
• Keywords: Electrical engineering, Condensed matter physics, Optics
• Date of Award: 1992
• Depositing User: Enlighten Team
• Unique ID: glathesis:1992-74429
• Copyright: Copyright of this thesis is held by the author.
• Date Deposited: 13 Nov 2019 15:58
• Last Modified: 13 Nov 2019 15:58
• URI: https://theses.gla.ac.uk/id/eprint/74429