A semiconductor light source comprises a substrate, lower and upper claddings, a waveguide region with imbedded active area, and electrical contacts to provide voltage necessary for the wavelength tuning. The active region includes single or several heterojunction periods sandwiched between charge accumulation layers. Each of the active region periods comprises higher and lower affinity semiconductor layers with type-II band alignment. The charge carrier accumulation in the charge accumulation layers results in electric field build-up and leads to the formation of generally triangular electron and hole potential wells in the higher and lower affinity layers. Nonequillibrium carriers can be created in the active region by means of electrical injection or optical pumping. The ground state energy in the triangular wells and the radiation wavelength can be tuned by changing the voltage drop across the active region.
The present invention was supported by the United States Air Force Research Laboratory under Contract No. F19628-02-C-0032 and by the United States Department of Energy under Contract No. DE-FG02-02ER83492. The present invention was also supported by ARO Grant No. DAAD190310259 and AFOSR Grant No. F49620-00-1-0331. The United States Government has certain rights in this invention.