Mode and gain analysis for symmetric and staggered grating-waveguide free-electron laser

Abstract

A grating-waveguide free-electron laser is driven by an axial electron beam that propagates between two planar gratings. This investigation addresses the mode analysis, gain calculation, and frequency tuning for such a device with arbitrary longitudinal and transverse displacements between the two gratings. It demonstrates that a grating waveguide free-electron laser is a promising coherent THz emitter when it is adopted as a backward-wave oscillator or a distributed-feedback oscillator.