Cherenkov Source Based on Oversized Two-Dimensional Surface Structure

Cherenkov oscillators based on intricate two-dimensional periodic surface lattice (2D-PSl) interaction cavities have the potential to produce powerful sub-terahertz radiation. To generate powerful radiation, whilst at the same time bridging the THz-gap, the transverse size
$D$
of the interaction cavity is designed to be several times the operating wavelength, A. In this vastly overmoded system, single frequency excitation can be achieved through the formation of a high-order cavity eigenmode, comprised of volume and surface fields. Numerical particle-in-cell simulations show megawatts of pulsed power, with excellent spectral purity. Theoretical and simulation results are presented for a pulsed Cherenkov oscillator based on a 2D-PSL with D/λ~5.5.