Towards High-Efficiency Mid-Infrared Diode Lasers Operating from 3-5 Microns

We have actively pursued GaSb-based dilute-nitride diode lasers to cover the 3-5 micron regime. We significantly advanced the growth understanding of GaSb-based dilute-nitride lasers, culminating in the first observation of room-temperature photoluminescence from a GaSb-based dilute-nitride quantum well. While the growth of these metastable alloys is challenging, we have identified a critical new issue governing the ultimate performance of these devices free-carrier absorption. Moreover, researchers already face this issue at shorter wavelengths 3 microns. We have invented a novel method for mitigating these losses, specifically GaSbErSbGaSb tunnel junctions, which we have developed through an Add-On Award. We have also developed a prototype GaInAsSbAlGaAsSb laser structure to serve as a testbed for examining dilute-nitride active regions, as well as the novel tunnel junction device structure.