Femtosecond dissipative quadratic soliton mode-locking of cavity-enhanced second-harmonic generation Journal Article uri icon

Overview

abstract

  • Abstract; Nonlinear frequency conversion underpins numerous classical and quantum photonics applications but conventionally relies on synchronized femtosecond mode-locked lasers and dispersion-engineered enhancement cavities—an approach that imposes substantial system complexity. To address the challenges, here we report a fundamentally different paradigm: mode-locking of nonlinear frequency conversion enabled by the physics of dissipative quadratic soliton (DQS). We present the operating principle of femtosecond DQS mode-locking and experimentally validate it for the first time in a continuous-wave-pumped doubly resonant second-harmonic generator in free space, yielding bichromatic frequency combs spanning the visible and near-infrared. The observed DQSs exhibit 3 dB optical bandwidths and transform-limited pulse durations of 1.15 THz and 274 fs for the pump and 1.13 THz and 279 fs for the second harmonic. By harnessing phase-matched group-velocity-matched cascaded quadratic nonlinearities, we demonstrate an in-situ tunable effective Kerr nonlinearity that exceeds the intrinsic material response by over three orders of magnitude, enabling femtosecond DQS generation in both free-space and chip-scale cavities across normal and anomalous dispersion regimes. Our results establish a simple, flexible, and scalable approach to nonlinear frequency conversion without the need for synchronized femtosecond mode-locked lasers and expand the reach of soliton-based technologies across diverse cavity platforms and a wide range of challenging wavelengths that are otherwise inaccessible.

publication date

  • December 1, 2026

Date in CU Experts

  • April 22, 2026 3:25 AM

Full Author List

  • Musgrave J; Nie M; Huang S-W

author count

  • 3

published in

Other Profiles

International Standard Serial Number (ISSN)

  • 2097-1710

Electronic International Standard Serial Number (EISSN)

  • 2662-8643

Additional Document Info

volume

  • 6

issue

  • 1

number

  • 15