Optically pumped submillimeter wave semiconductor lasers

An optically pumped multiple quantum well (MQW) submillimeter wave (SMMW) laser is proposed and designed. The laser can potentially generate significant power in the far-infrared regime. It is based on pumping of a series of InGaAs-GaAs quantum wells with a CO₂ laser. The excited electrons created by the pumping process tunnel into the upper of two subband states in an AlGaAs-GaAs quantum well grown in series with the absorption wells, and thereby give rise to a population inversion between these two states which are tuned to the SMMW frequency desired. The authors present the key concepts of the new device and some designed device structures