Distributed feedback quantum cascade lasers at $13.8μm$ on indium phosphide

We report on the growth, processing, and characterization of distributed feedback quantum cascade lasers emitting in single mode at $13.8μm$⁠. Lasers were grown in the indium phosphide material system with a bound-to-continuum active region and processed as double channel ridges with metalized top grating. Electro-optic characteristics as well as current and temperature tuning are investigated. Maximum single mode peak powers exceeding 800 mW at room temperature and intrapulse-tuning covering $3cm−1$ for a gas absorption experiment are demonstrated. Furthermore data on the far field are presented showing a slow-axis divergence angle of 28.3° (full width at half maximum).