Cascaded nonlinear pulse compression: impact on temporal contrast

With the advent of novel high-energy, high-repetition-rate, commercially available sub-ps laser sources, there is a growing demand for reliable pulse compression systems that match pulse durations to those of the old “workhorse” of ultrafast science — Ti:Sapphire lasers. However, large compression factors (>20) compromise temporal pulse quality and result in the formation of a low-intensity pedestal, lowering the effective peak power and leading to unwanted effects such as pre-ionization and material heating. Splitting the nonlinear post-compression into multiple stages helps mitigate pedestal formation and improves pulse quality on the picosecond timescale. Moreover, manipulating the pulse spectrum and polarization during nonlinear broadening enhances temporal contrast on the hundreds of picoseconds to nanosecond timescales. In this contribution, we explore the parameter space of cascaded pulse compression systems to achieve optimal performance for internal confinement laser-driven fusion, Coulomb explosion, material processing, and medical applications.