Tapered Fibre Fabry-Pérot Cavities for the Generation of Near-Visible, Phase-locked, and Broadband Kerr Frequency Combs

By incorporating micron-diameter tapered silica fibre into a pulsed-driven Fabry-Pérot configuration, we exploit geometric dispersion engineering to overcome the strong normal dispersion intrinsic to silica (and nearly all materials) at short wavelengths, achieving net anomalous dispersion in the near-visible regime.

The strong mode confinement of the tapered fibre simultaneously enhances the Kerr nonlinearity by over an order of magnitude relative to standard fibre, substantially reducing the threshold drive power for nonlinear structure formation. Through precise control of the cavity fabrication, we experimentally demonstrate and numerically confirm a rich suite of coherent, phase-locked nonlinear structures, including conventional anomalous dispersion cavity solitons, zero dispersion solitons with spectral bandwidths exceeding 16 THz between 750 nm and 800 nm, as well as switching wave combs and broadband Raman solitons, the latter also reported here for the first time in the near-visible regime.