1 results about "Tunnel injection" patented technology

Quantum cascade lasers (QCLs) are provided, which in embodiments comprise a plurality of stages, each stage comprising alternating quantum well layers and barrier layers, wherein each stage is configured, upon application of an electric field F across the plurality of stages, to inject carriers from a low energy state of an adjacent, upstream stage of the plurality of stages into a high energy state of a lasing stage of the plurality of stages, via tunneling injection through multiple barrier layers comprising barrier layers of the adjacent, upstream stage and barrier layers of the lasing stage, wherein carriers in the lasing stage undergo intraband transitions from an upper laser level of the lasing stage to at least one lower laser level of the lasing stage with the emission of laser light and without carrier leakage.