Linewidth enhancement factors of short external cavity semiconductor lasers

Abstract

<p>This thesis describes the development of a method for measuring the tuning of the emission frequency of semiconductor lasers. This method employs a short external cavity (SXC) mirror, as an external optical feedback element, to alter the resonant condition of the lasers. The experimental system, which includes an SXC laser module constructed out of a flexure mount concept, was derived from this method. The system was used to make measurements of the frequency tuning of InGaAsP multi-quantum well lasers. Linewidth enhancement factors of these lasers were calculated from the experimental data. It was found that the linewidth enhancement factors of these lasers depend on the wavelengths of emission and are fairly independent of the output powers. It was also found that the linewidth enhancement factors of these lasers decrease as the band gap of the barriers of the quantum wells increases.</p>