High-power, narrow-ridge, mid-infrared interband cascade lasers

Two ten-stage interband cascade laser structures were grown by solid-source molecular beam epitaxy. The wafers were processed into both broad-area ridges for threshold characterization and Au-electroplated narrow ridges for high-temperature cw operation. Pulsed threshold current densities in the broad-area devices were as low as 3.8 A/cm2 at 78 K and 590 A/cm2 at 300 K. An 11-μm-wide ridge exhibited a new maximum cw operating temperature of 288 K at λ=4.1 μm. An even longer-wavelength device emitted at 5.1 μm with a maximum cw operating temperature of 229 K.