Optical frequency combs generated in normally dispersive Kerr microresonators have been observed to correspond to dark temporal structures, and theoretically explained as interlocked switching waves (also known as domain walls or fronts). The time-domain dynamics that underpin the formation of this type of frequency combs has however so far eluded direct experimental observation. Here we use a closely related system – a synchronously driven optical fibre ring resonator – to experimentally study the dynamics of deterministically excited switching waves. We measure the switching wave velocities across broad parameter regions, and observe clear signatures of interlocking behaviour leading to the formation of persisting dark pulses. Our experimental findings are in good agreement with simulations of the mean-field Lugiato-Lefever equation, and strongly support the nature of normal-dispersion microresonator frequency combs suggested in the literature.
|Number of pages||8|
|Journal||European Physical Journal D: Atomic, Molecular, Optical and Plasma Physics|
|Publication status||Published - 19 Sept 2017|
- switching waeforms
- dark pulses
- Lugiato-Lefever equation