Interband Cascade Lasers with CW Wallplug Efficiency Higher than 40 at Low Temperatures

摘要

We report cw wallplug efficiencies (WPEs) for mid-infrared interband cascade lasers (ICLs) that are comparable to those of state-of-the-art quantum cascade lasers at temperatures ranging from the cryogenic regime to room temperature. The continuous wave (cw) WPE for 10-stage broad-area devices remains above 40% for temperatures up to 125 K, and is still ＞30% at T= 175 K. At 80 K the threshold current density for a 2-mm-long cavity is only 11 A/cm~2, and slope efficiencies are ＞ 2.2 W/A at all temperatures ≤ 200 K. A 32-μm-wide × 3-mm-long ridge with 7 active stages and high-reflection and anti-reflection coatings on the two facets displays a cw WPE of 24% at T= 200 K and 12% at T= 300 K. The cw WPE of another narrow-ridge ICL was 18% at room temperature.