Carrier capture competition between two different quantum wells in dual-wavelength semiconductor lasers

Based on a three-level model, we have numerically shown that a semiconductor gain medium with a structure consisting of two different quantum wells may lead to dual-wavelength laser operation if the balance of carrier capture competition between the two wells can be reached. The major controlling parameters for the operation are the ratio of the carrier quantum capture times of the two wells and the absorption constant of the short-wavelength photons by the long-wavelength quantum well. It is shown that there exists a large parameter space for dual-wavelength operation.