Narrow Ridge $\lambda \approx 3$ - $\mu \text{m}$ Cascade Diode Lasers With Output Power Above 100 mW at Room Temperature

Abstract

Shallow narrow ridge two-stage cascade GaSb-based type-I quantum well diode lasers emitting at $\lambda \approx 3~\mu \text{m}$ were designed and fabricated. Efficient carrier recycling improved the device power conversion and slope efficiencies as compared with the standard multiple quantum well diode lasers. Devices generated more than 100 mW of continuous-wave output power in nearly diffraction limited beam at room temperature. Studies of the current dependence of the modal gain spectra confirmed increased tendency to lateral current spreading in cascade laser heterostructures as compared with the regular diode lasers.