THz-FIR grating coupled radiation source

Summary form only given. The operation of a new coherent tunable FIR-THz source has been demonstrated. The device makes use of the electron beam in a scanning electron microscope (SEM) and a diffraction grating mounted in the e-beam focal region to produce the radiation. Distributed feedback is provided by the grating itself. A variation on the basic Smith-Purcell radiation theme, the source is described as a grating coupled oscillator (GCO).