Improve growth rate of Smith–Purcell free-electron laser by Bragg reflector

Abstract

Grating with Bragg reflectors for the Smith–Purcell free-electron laser is proposed to improve the reflection coefficient, resulting in enhancing the interaction of the surface wave with the electron beam and, consequently, relax the requirements to the electron beam. With the help of particle-in-cell simulations, it has been shown that the usage of Bragg reflectors may improve the growth rate, shorten the time for the device to reach saturation, and lower the start current for the operation of a Smith–Purcell free-electron laser.