New semiconductor lasers based on intraband transitions of injected carriers in quantum wells

Summary form only. Mid infrared (MIR) semiconductor lasers (/spl lambda/=4-15 /spl mu/m) can find a wide applications in different fields. Two types of such lasers based on intersubband transitions of carriers in quantum well (QW) structures have been already realized. These are quantum cascade lasers (QCL) and fountain lasers with optical pumping. Two new types of MIR intersubband lasers are suggested in this paper. These lasers have both the simplicity of design and technology (growth) and convenient in practice. Inversion of population appears due to current injection or under interband optical pumping by compact semiconductor laser. Both designs contain asymmetrical funnel-shape QWs for electrons with three levels of size quantization.