On non-uniform pumping effects in semiconductor lasers

Abstract

<p>We present a study of non-uniform pumping effects in semiconductor lasers. The first portion of this work is a theoretical undertaking, in which a physical model of a split-electrode, ridge-waveguide, InGaAsP/InP laser is developed. This model is based on the time-dependent solution of the carrier and photon rate equations, and is capable of describing such device features as multiple electrical contacts, illumination of the facets via an external light source, multiple optical cavity modes, and continuous variations in the carrier and photon concentrations. The simulations generated from this model demonstrate: (1) output power vs. bias characteristics that include threshold control, discontinuities, and bistability, (2) wavelength tuning via gain peak shifts and varying refractive index, (3) self-sustained pulsations caused by repetitive Q-switching, (4) external injection effects such as injection locking, all-optical switching, and optical self-pulsation control, and (5) current modulation characteristics. The effects of varying the device bias and geometric parameters on these phenomena are presented. The second part of the thesis consists of an experimental investigation of a series of multi-quantum well InGaAsP/InP split-contact lasers. By varying the bias currents and contact lengths, we have studied their effects on the output power and spectra of these devices. The experimental results we present are in good agreement with the simulations based on our theoretical model.</p>