Selective oxidation in heterostructures improves VCSEL efficiency

Selective oxidation in heterostructures improves VCSEL efficiency

The electrical-to-optical power conversion efficiency in 980-nm InGaAs vertical-cavity surface-emitting-lasers (VCSELs) has been increased to 53% in devices targeted for optical data link applications. Developers at Sandia National Laboratories (Albuquerque, NM) said that this efficiency represents an improvement of 2.5 times over their previous record reported last year. The differential quantum efficiency at the 1-mW level was also significantly improved to 78%. The scientific team, including Kent Choquette, Kevin Lear, and Richard Schneider, used a series of advances in the design and growth of a very complex multilayered heterostructure device, combined with "selective oxidation" technology, to fabricate the low electrical resistance and high optical and electrical confinement needed to improve the efficiencies.