Spectral analysis of self-pulsating laser diodes with absorbing epitaxial layers

Summary form only given. Repetitively Q-switched or self-pulsating semiconductor lasers are key components in high density optical storage systems such as digital versatile disc (DVD) where low intensity-noise sources are required. The saturable absorption required to produce the Q-switched action can be provided by an epitaxial layer placed within the cladding regions of the laser. This provides a mechanism by which the absorption characteristics can be engineered via the position, thickness and material composition of the layer. Thus the gain and dispersion characteristics can be controlled to optimise the self pulsation characteristics. We have fabricated laser diodes with such epitaxial absorbers operating at 650 nm which exhibit self-pulsating behaviour over a wide range of injection currents and temperatures.