Abstract

Long wavelength quantum well lasers with ungraded confinement barriers have not performed as well as expected in high-speed applications. This has prompted considerable interest in the carrier transport, heating, and capture mechanisms, which limit the modulation response. It has been argued that poor transport of the lower mobility holes across the optical confinement barriers is the main factor, but electron capture may also be important. Largely because of the lower density of states in the conduction band well compared to the valence band, electrons are less readily captured than holes. Rate equation analysis has been widely used to demonstrate the effect of transport and other mechanisms upon the modulation response of semiconductor lasers. Although this approach is very useful in producing a macroscopic picture of the device operation, it cannot take full account of ambipolar effects or spatial inhomogeneities.

© 1996 Optical Society of America