TUNNEL INJECTION LASERS

Abstract

Carrier heating in conventional quantum well lasers can lead to several deleterious effects and are related to the transport and thermalization characteristics of injected carriers. The properties of a quantum well laser in which the electrons are directly transported to the lasing subband by tunneling is described here. The resulting device — a tunnel injection laser — is shown to have negligible gain compression, superior high-temperature performance, lower Auger recombination and wavelength chirp, and better high frequency modulation characteristics when compared to conventional lasers. All these improvements are attributed to the reduction of hot-carrier population in the active region of the laser. Results are presented here for lasers made with GaAs — and InP — based heterostructure systems.