Research of Volume Free-Electron Laser with Photonic Crystal Structure for Operation in Sub-Terahertz Range

In this work, we present the results of the numerical optimization of volume free-electron laser based on the interaction between an electron beam and periodic structure of microwave photonic crystal. The optimization aims at the advancement of such device to the sub-terahertz frequency range. We show that the reduction of characteristic geometric dimensions allows increasing the working frequency of photonic crystal fundamental mode up to 12.5 GHz. Moreover, we observe the possibility to generate microwaves at the fifth harmonic of the fundamental frequency, namely f=62.5 GHz and obtain an output power level of about 3.6 kW.