Improved mid-infrared interband cascade light-emitting devices

We report interband cascade light-emitting devices (ICLEDs) emitting at peak wavelengths of 3.1 to 3.2 μm that display higher maximum output powers, radiances, and efficiencies than any earlier midwave-infrared LEDs when operated at 10 to 105°C. To enhance the output power, we split the ICLED’s 22 active stages into four groups positioned at antinodes of the optical field so that the emission interferes constructively when reflected at near-normal incidence from the metal contact of the epitaxial-side-down mounted device. At an applied bias of 9.6 V and injection current of 0.6 A, an ICLED with mesa diameter of 400 μm produces 3.1 mW of continuous-wave output power at T=10°C, which corresponds to a radiance of 0.79 W/cm2/sr. The same device generates 1.7 mW at T=105°C.