Toward far- and mid-IR intraband lasers based on hot carrier intervalley/real-space transfer in multiple quantum well systems

Discussion of ways to achieve mid and far IR intraband lasing just by lateral electric field carrier (electron or hole) heating in multiple quantum well (MQW) structures is given. It is argued that the Gunn diodes are low frequency indirect transition lasers based on hot electron population inversion arising under electron intervalley transfer. In the MQW structures direct optical transitions exist while hot carrier population inversion can be achieved due to inter-valley/real space transfer. The two MQW structures are considered in this work: GaAs/AlAs and GaAs/InGaAs systems. In the first the hot electron (Gamma) -X intervalley/real space transfer from GaAs layers to AlAs layers provides population inversion while in the second the inversion can arise due to interlevel/interlayer transfer. Evaluations via the Monte-Carlo simulation of the hot electron phenomena in some of the structures are given and observation of the hot carrier phenomena of the type (including far and mid IR emission and absorption) are presented. Consideration of the appropriate laser design which provides also a way to cope with the low frequency (Gunn type) current oscillations is given.© (2001) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.