Recent advances in mid infrared (3-5μm) Quantum Cascade Lasers

Quantum cascade laser (QCL) is an important source of electromagnetic radiation in mid infrared region. Recent research in mid-IR QCLs has resulted in record high wallplug efficiency (WPE), high continuous wave (CW) output power, single mode operation and wide tunability. CW output power of 5.1 W with 21% WPE has been achieved at room temperature (RT). A record high WPE of 53% at 40K has been demonstrated. Operation wavelength of QCL in CW at RT has been extended to as short as 3 mu m. Very high peak power of 190 W has been obtained from a broad area QCL of ridge width 400 mu m. 2.4W RT, CW power output has been achieved from a distributed feedback (DFB) QCL. Wide tuning based on dual section sample grating DFB QCLs has resulted in individual tuning of 50cm(-1) and 24 dB side mode suppression ratio with continuous wave power greater than 100mW. (C) 2013 Optical Society of America