Abstract

We report a novel laser cavity design in third-order distributed feedback terahertz quantum-cascade lasers based on true phase-matching technique. This approach dramatically increases the usable length of third-order DFB lasers and leads to even narrower beam patterns and likely higher output power. Single frequency emissions from 150 apertures (5.6-mm long device) are coherently added up to form a narrow beam with ∼ 6° divergence. Similar device with 40 apertures shows more than 5mW optical power with slope efficiency∼ 140mW/A at 10K pulsed operation.

© 2011 Optical Society of America