Multi-W, 100-Khz, Few-Cycle Mid-Infrared Source With Sub-100-Mrad Single-Shot Carrier-Envelope Phase Noise

Extension of High order Harmonics Generation (HHG) towards XUV and up to soft-x-rays relies on the development of driving sources with specific properties: mid-infrared wavelength, few-cycle pulse duration, high peak intensity, carrier-envelope phase stability and control, high energy and/or high-repetition rate. While longer wavelengths of the driving source extend the HHG cutoff energy through the λ 2 dependency of the ponderomotive energy, shorter pulses lead to the higher peak intensities enhancing the HHG conversion yield and extending HHG cutoff energy even further. Additionally, few-cycle driving pulses reduce the number of produced attosecond bursts up to, ideally, a single isolated attosecond pulse. In this case, CEP stability and control is paramount for ensuring optimization and shot-to-shot reproducibility of the HHG yield and spectra.