Metal-to-metal waveguide for radiation in the THz range and quantum cascade laser with such a waveguide

摘要

Metal-metal waveguide for a quantum cascade laser (1) for generating an electromagnetic radiation in the THz range, in which waveguide (2) the height of the active medium (7) is bounded by in each case a metal layer (5, 8), which waveguide ( 2) has an outcoupling surface (9) for decoupling generated THz radiation at its end pointing in the direction of radiation propagation, the end section of the waveguide (2) having the outcoupling surface (9) by providing at least one expansion region (11) in which radiation transversely for the longitudinal extension of the active medium (7) expands therefrom into the outer dielectric, a reduced refractive index relative to the remaining portions of the waveguide (2), characterized in that the at least one expansion region (11) of the waveguide (2) in the radiation propagation direction in one tuned to the wavelength of the electromagnetic radiation is such manner t, so that in the at least one expansion area (11) takes place constructive interference.