Perfectly phase-matched third-order distributed feedback terahertz quantum-cascade lasers.
We report a novel laser cavity design in third-order distributed feedback (DFB) terahertz quantum-cascade lasers based on a perfectly phase-matching technique. This approach substantially increases the usable length of the third-order DFB laser and leads to narrow beam patterns. Single frequency emissions from 151 apertures (5.6 mm long device) are coherently added up to form a narrow beam with (FWHM≈6×11°) divergence. A similar device with 40 apertures shows more than 5 mW of optical power with slope efficiency ∼140 mW/A at 10 K pulsed operation.
Department of Electrical Engineering and Computer Science & Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA. wilt_kao@mit.edu
Tsung-Yu
TY
Kao
Qing
Q
Hu
John L
JL
Reno