Enhanced super-radiant emission of FEM near waveguide-cutoff and near zero-slippage conditions

We report on super-radiance obtained from the TAU FEM just above waveguide cutoff and near grazing intersection. g intersection (or “Zero Slippage”) is defined as the point at which the two synchronous frequencies merge to one frequency. In this case, the radiated power frequency can be tuned over a very wide band by change of the pre-modulation frequency. he lower synchronous frequency, the super-radiance power is much greater and the spectral width is much narrower than those at the higher synchronous frequency. per-radiance emission near cutoff (lower synchronous frequency) and near to the upper synchronous frequency was measured and compared to those predicted by an analytical model for a wide range of frequencies.