Terahertz Planar Diode Oscillator with Field Emitter Arrays as Cathode

The terahertz wave generator is a key component for various applications of terahertz technology. Here we propose a terahertz planar diode oscillator with field emitter arrays (FEA) as cathode. Electrons emitted from FEA cathode are pre-modulated by the self-excited terahertz oscillation field and then amplify this field. Field distribution with space charge effect is first investigated. Then we derive the equations governing the beam-wave interaction by using small-signal theory and obtain the operation frequency that determined by inter-electrode voltage and distance. For a planar diode with DC bias of 0.5-2.5 kV, cathode-anode distance of 10–50 micron, the operating frequency covers the range of 0.1-1THz. This terahertz oscillator possesses simple configuration, as well as tunable operating frequency, making it promising candidate for micro-scale tunable terahertz source.