Design Considerations for Compact High-Average Power Free-Electron Lasers/Masers at Terahertz Frequencies

Interest is increasing in high-power terahertz (THz) sources of radiation. The terminology is fluid, but researchers in the field typically refer to frequencies ranging from about 300 GHz to 10 THz as THz radiation. In this article, we present a description of design considerations for a compact, high-average power free-electron laser. At present, THz radiation is generated by a variety of mechanisms, including laser-based sources and electron-beam-based sources. We provide a short description of current THz source technology to give background against which to compare the present concept; however, this should not be considered a comprehensive discussion of such technologies.

I. Introduction

This article focuses on electron-beam-based terahertz (THz) sources capable of high peak and average powers, particularly a compact high-power free-electron laser (FEL). In the literature, “THz” is often used to describe sources ranging in frequency from full THz down to approximately 100 GHz.