THz time domain spectroscopy of coupled cavity THz quantum cascade lasers with metal-metal waveguide

In this contribution this concept is presented to be suitable for launching mode matched THz pulses on the subwavelength facet of a metal-metal THz QCL. For gain and loss studies of the THz QCL a coupled cavity scheme is introduced. The first (short) cavity is acting as a THz emitter while the second (longer) cavity acts as a device under test, i.e. an amplifier for the transmitted THz pulses.