Mid-infrared high-peak power quantum cascade lasers are highly useful in many applications such as gas sensing and free-space communication. However, practical application scenarios place further demands on the wavelength tunability and integration of the devices. Here, we proposed an on-chip wide tuning scheme for high-peak power quantum cascade lasers based on a vertically integrated heater. The device exhibits a high peak output power of 12.6 W at λ ～ 8.9 μm with a stable single-mode operation and a high side-mode-suppression ratio of 30 dB. The wavelength tuning range is extended to 16.1 cm^?1 using the designed on-chip heater, over one-order of magnitude wider than that of pure electrical tuning to the device. A wider continuous tuning range of 45.2 cm^?1 was further realized by incorporating a multi-wavelength distributed-feedback design. The demonstrated tuning scheme is simple in fabrication without any epitaxy regrowth and provides a favorable approach to the on-chip widely tunable quantum cascade lasers and their applications in fields such as multi-gas sensing and environmental monitoring. 

Paper link: https://pubs.aip.org/aip/app/article/10/9/096105/3361844/On-chip-wide-tuning-of-high-power-quantum-cascade