Bridging Coherent Octave-Spanning Supercontinuum Generation and Integrated Laser Sources

Integrated octave-spanning frequency combs are crucial for portable precision metrology, yet existing methods face major hurdles<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1</sup>. Integrated Kerr combs in microresonators struggle with bandwidth and repetition rates incompatible standard RF electronics<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup>. While supercontinuum generation (SCG) in waveguides achieve octave spans, it demands high-peak-power (up to kW) femtosecond pulses, far exceeding capabilities of chip-scale sources (~W, ps)<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sup>. This pump mismatch blocks progress towards fully integrated systems. Here, we introduce a new SCG paradigm in highly nonlinear aluminum-gallium-arsenide-on-insulator (AlGaAsOI) waveguides using cascaded four-wave mixing (CFWM) mediated by parametrical amplification. This enables coherent octave-spanning combs driven by watt-level picosecond pulses, drastically reducing requirements and bridging the gap to integrated laser compatibility.