High-temperature and low-threshold midinfrared interband cascade lasers

摘要

A broad-area midinfrared interband cascade (IC) laser has been demonstrated with a threshold current as low as ～630 A/cm~2 at 300 K. Despite exhibiting a large specific thermal resistance (～56 K cm~2/kW at 172 K), the device delivered cw power near 200 mW/facet at 500 mA and at 83 K and lased in cw mode up to 172 K. A 0.5-mm-long laser delivered cw power of ～253 mW/facet at 400 mA and at 82 K, and had power efficiency as high as 26% at ～80 K. Narrow mesa stripe IC lasers had relatively higher threshold current density, yet lased at temperatures up to 237 and 350 K in cw and pulsed modes, respectively. The feasibility of cw operation at higher temperatures and directions for improving IC laser performance are discussed based on the experimental data.