Abstract

The ability to generate low-noise cavity soliton (CS) frequency combs in coherently-driven Kerr nonlinear resonators has enabled a host of applications over the past decade [1]. Some of the characteristics of such combs are governed by the innate nonlinear dynamics of the solitons that underpin them, which may hinder some applications. For instance, CSs originate from direct external driving, and are therefore spectrally centred around the driving laser (ω_p) and temporally sit atop a non-negligible continuous wave background; moreover, CSs correspond to unique attractors, prohibiting applications that may require two (or more) distinct entities. Recently, a new class of temporal CSs has been demonstrated that does not exhibit these characteristics, and could find use in a new range of applications: parametric down-conversion in a resonator with simultaneous χ⁽²⁾ and χ⁽³⁾ (Kerr) non-linearities was shown to allow for the generation of parametrically-driven cavity solitons (PDCSs) centred at half the driving frequency (ω_p/2) and that come in two distinguishable forms with opposite phase [2]. Unfortunately, this scheme cannot be translated to common (foundry-ready) materials that lack a χ⁽²⁾ nonlinearity.

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