Abstract-Two-Color TeraHertz Radiation by a Multi-Pass FEL Oscillator

 

Michele Opromolla,  Vittoria Petrillo,

https://www.mdpi.com/2076-3417/11/14/6495

In this paper, we show that an electron beam produced by a super-conducting linac, driven in a sequence of two undulator modules of different periods, can generate two-color Terahertz radiation with wavelengths ranging from 100 μ$$m to 2 μ$$m. The generated pulses are synchronized, both MW-class, and highly coherent. Their specific properties and generation will be discussed in detail. Besides the single-spike pulse structure, usually observed in oscillators, we show that both the THz pump and probe can be modulated in a coherent comb of pulses, enabling periodic excitation and stroboscopic measurements.