Experimental and numerical investigations of switching wave dynamics in a normally dispersive fibre ring resonator*
1 The Dodd-Walls Centre for Photonic and Quantum Technologies, Department of Physics, The University of Auckland, 1142 Auckland, New Zealand
2 SUPA and Department of Physics, University of Strathclyde, Glasgow G4 0NG, UK
Received: 28 February 2017
Received in final form: 12 July 2017
Published online: 19 September 2017
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.
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag 2017