Tunable megawatt-scale sub-20 fs visible pulses from a fiber laser source

Tunable ultrashort laser pulses across the near-ultraviolet to near-infrared with high peak power are crucial for wide-ranging applications in science and industry. Resonant dispersive-wave emission in gas-filled hollow-core fibers is a well-established technique for generating tunable ultrashort pulses from the vacuum ultraviolet to the near-infrared. However, previous demonstrations have relied on complex and expensive laser systems to provide the necessary energetic ultrashort pump pulses. Recent advances in fiber laser technology, particularly gain-managed nonlinear amplification, offer a promising alternative pump source. In this work, we combine gain-managed nonlinear amplification with resonant dispersive-wave emission to demonstrate a compact and tunable source of sub-20 fs pulses at 4.8 MHz. We achieve a tunable output spanning from 400 nm to beyond 700 nm, with energy up to 39 nJ, pulse duration down to 13 fs, and peak power exceeding 2 MW. This compact and efficient laser source opens new avenues for deploying resonant dispersive-wave-based technologies for broader scientific and industrial applications.