Buried heterostructure lasers for metropolitan area networks: anomalous low temperature behaviour

Buried heterostructure (BH) lasers are key sources for optical fibre communication systems and integrated optoelectronics. We have initiated a study of the low-temperature behaviour of these lasers with a view to gaining insight into the mechanisms which limit their performance as directly modulated sources for optical communications systems. In particular, we have focussed on the effect of quantum transport bottlenecking during ambipolar injection across quantum wells, a mechanism widely viewed as responsible for limiting these lasers to operating below their ultimate modulation bandwidth.