Injection cascade lasers with graded gap barriers

Abstract

We propose cascade structures based on type-II heterostructures with graded barriers separating electron and hole layers. The electron–hole separation is controlled by an external bias due to modification of the barrier shape. This principle can be used for fabrication of a class of devices. In particular, bipolar interband cascade lasers are considered in which an external bias changes the rate of electron–hole radiative recombination by several orders of magnitude. Theoretical calculations predict the feasibility of these lasers.