Interband Cascade Lasers with Wavelengths Spanning 3.2–4.2 μm

Abstract

We report a detailed experimental investigation of five interband cascade lasers with five active stages each and emitting at wavelengths between 3.2 μm and 4.2 μm at room temperature. Pulsed threshold current densities as low as 394 A/cm2 and voltage efficiencies as high as 76% are obtained at 300 K. The low pulsed threshold power densities (0.9–1.6 kW/cm2 at 300 K) imply that ambient-temperature cw operation should be possible over the entire spectral band once optimized narrow ridges can be fabricated.