Dual-band terahertz wave generation device and method

Abstract

The invention relates to a dual-band terahertz wave generation device and method. The device comprises an emission cathode, a collector and a metal grating, wherein the emission cathode and the collector are arranged above the metal grating, the emission cathode can emit electron beams, and the collector can receive the electron beams; one side, close to the emission cathode and the collector, of the metal grating is provided with N first rectangular grooves and N second rectangular grooves, the depths of the first rectangular grooves and the depths of the second rectangular grooves are different, and the first rectangular grooves and the second rectangular grooves are periodically arranged on the metal grating. When the working voltage of the electron beam is greater than the maximum cut-off working voltage in the metal grating, dual-band surface plasmons can be excited, so that terahertz waves are generated by utilizing the interaction of the electron beam and the surface plasmons. The scheme provided by the invention can realize high-efficiency excitation of dual-band terahertz waves, and also has the advantage of wide-band working.

Description

technical field [0001] The present invention relates to the technical field of terahertz waves, in particular to a dual-band terahertz wave generating device and method. Background technique [0002] Surface plasmon polaritons (SPP) is a special optical mode that exists on the interface between metal and medium, but as the frequency moves down to the terahertz and microwave bands, due to the ideal conductor-like properties of metals, Surface plasmons become poorly localized on homogeneous metal surfaces. By periodically slotting or punching holes on the metal surface, the local adhesion of surface plasmons becomes stronger, and its equivalent asymptotic frequency can be adjusted arbitrarily through periodic structural parameters, so it is also called artificial surface, etc. excitons. [0003] In recent years, artificial surface plasmons with periodic metal structures have been used in terahertz integrated waveguides, couplers, and power splitters due to their excellent el...

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Problems solved by technology

[0005] However, the conversion efficiency of the above-mentioned terahertz generating device through infrared laser injection is low, and the electron beam threshold required to generate terahertz radiation through the free laser excited by the electron beam is relatively large, and the periodic metal structure adopted is a single The depth of surface plasmons can only work in a single frequency band, so the generated terahertz radiation also works in a single frequency band, and the bandwidth is relatively narrow

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