Quantum cascade lasers: Ultrahigh-speed operation, optical wireless communication, narrow linewidth, and far-infrared emission

Federico Capasso, Roberto Paiella, Rainer Martini, Raffaele Colombelli, Claire Gmachl, Tanya L. Myers, Matthew S. Taubman, Richard M. Williams, Clyde G. Bethea, Karl Unterrainer, Harold Y. Hwang, Deborah L. Sivco, Alfred Y. Cho, A. Michael Sergent, H. C. Liu, Edward A. Whittaker