1Key Lab of Semiconductor Materials Science, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083 2Beijing Key Laboratory of Low Dimensional Semiconductor Materials and Devices, Beijing 100083 3College of Materials Science and OptoElectronic Technology, University of Chinese Academy of Sciences, Beijing 100049
Abstract：An external cavity quantum cascade laser (QCL) array with a wide tuning range and high output power is presented. The coherent QCL array combined with a diffraction grating and gold mirror is tuned in the Littrow configuration. Taking advantage of the single-lobed fundamental supermode far-field pattern, the tuning capability of 30.6 cm$^{-1}$ is achieved with a fixed injected current of 3.5 A at room temperature. Single-mode emission can be observed in the entire process. The maximum single-mode output power of the external cavity setup is as high as 25 mW and is essential in real applications.
Young C, Cendejas R, Howard S S, Sanchez-Vaynshteyn W, Hoffman A J, Franz K J, Yao Y, Mizaikoff B, Wang X J, Fan J and Gmachl C F 2009 Appl. Phys. Lett.94 091109
2017, Vol. 34 
