THz modulation bandwidth prediction for intersubband semiconductor lasers

Summary form only given. Intersubband lasers have become a topic of active research particularly following the development of mid-infrared quantum cascade lasers. Subsequent research has given rise to significant developments in the performance of these lasers. In this context it is of considerable interest to consider in detail the achievable direct current modulation characteristics of unipolar lasers. It is noted that the picosecond carrier lifetimes which are characteristic of the operation of intersubband lasers may be anticipated to offer opportunities for THz bandwidth modulation in such lasers. Previous studies indicated that modulation bandwidths of order 150 GHz would be obtainable in the chosen structure. In the present work attention is concentrated on demonstrating that unipolar lasers have the potential for achieving THz modulation bandwidths.