Tunable terahertz quantum cascade lasers with external gratings

• Main Authors: Lee, Alan (Contributor), Williams, Benjamin S. (Contributor), Kumar, Sushil (Contributor), Hu, Qing (Contributor), Reno, John L. (Author)
• Other Authors: Massachusetts Institute of Technology. Department of Electrical Engineering and Computer Science (Contributor), Massachusetts Institute of Technology. Research Laboratory of Electronics (Contributor)
• Format: Article
• Language: English
• Published: Optical Society of America, 2014-05-02T14:40:21Z.
• Subjects: Article
• Online Access: Get fulltext

We demonstrate a frequency tunable external cavity terahertz quantum cascade laser using an abutted antireflection-coated silicon lens to reduce facet reflection and as a beam-forming element, with an external grating providing frequency selective optical feedback. Angle tuning of the grating allows a single longitudinal mode of the laser ridge to be selected, resulting in discontinuous tuning over a 165 GHz range around a center frequency of 4.4 THz. Another device exhibited 145 GHz of total tuning with 9 GHz of continuous tuning near the longitudinal modes of the laser.
United States. Air Force Office of Scientific Research
United States. National Aeronautics and Space Administration
National Science Foundation (U.S.)