Generation of Intense Femtosecond Pulses Beyond 3000 nm Using OPCPA Combined with Transient Rotational SRS in Hydrogen

Intense femtosecond pulse laser sources in the wavelengths range ~1. 8–3 μm are in demand for the generation of THz and attosecond X-ray pulses [1], particle acceleration and remote sensing, X-ray spectroscopy, biological or nanoscale imaging, laser medicine, and material processing by direct excitation of phonon modes. Several approaches to delivering intense ultrashort laser pulses in the wavelength range greater than ~2 μm have been explored. The most advanced sources have been shown to be primarily based on optical parametric chirped pulse amplification (OPCPA), operating in the degeneracy range when pumped by a single-picosecond lasers near ~1 μm.