Coherent High-Harmonic Generation with Laser-Plasma Beams

Active energy compression scheme is presently being investigated for future laser-plasma accelerators. This method enables generating laser-plasma accelerator electron beams with a small, ~ 10⁻⁵, relative slice energy spread. When modulated by a laser pulse, such beams can produce coherent radiation at very high, ~ 100-th harmonics of the modulation laser wavelength, which are hard to access by conventional techniques. The scheme has a potential of providing additional capabilities for future plasma-based facilities by generating stable, tunable, narrow-band radiation.