Theory of asymmetric dual quantum well lasers

A basic theory of asymmetric dual quantum well lasers is presented. The lasers consist of two quantum wells of different energy gaps, which are separated by a high and/or thick barrier layer. The barrier layer blocks carrier transport between the wells so that the rate of the transport becomes comparable to the rate of the radiative recombination. It is shown that this leads to novel phenomena of dual-wavelength lasing and wavelength switching with increasing injection current, in agreement with recent experimental results.