Resonant-phonon terahertz quantum cascade lasers at long wavelengths

We report a resonant-phonon terahertz quantum cascade laser at a wavelength of /spl lambda/ /spl ap/ 141 /spl mu/m (2.1 THz) that uses a low-loss, high-confinement metal-metal waveguide. Continuous wave operation is obtained up to 40 K.