Optical gain analysis of strain-compensated InGaN–AlGaN quantum well active regions for lasers emitting at 420–500 nm

Abstract

Strain-compensated InGaN quantum wells with tensile AlGaN barriers are analyzed as improved gain media for laser diodes emitting at 420–500 nm. The band structure is calculated using the 6-band k ·p formalism, taking into account valence band mixing, strain effect, and spontaneous and piezoelectric polarizations. The optical gain analysis exhibits significant improvement in the peak optical gain and differential gain for the strain-compensated structures. The calculation also shows a significant reduction of threshold carrier density and current density for diode lasers employing the strain-compensated InGaN–AlGaN QW active regions.