Cavity solitons are localised nonlinear structures that exist in passive Kerr cavities pumped by an external coherent driving field. Temporal cavity solitons are the temporal analogue of the better known spatial cavity soliton and exist as temporally localised pulses in passive Kerr rings. Possible applications of temporal cavity solitons include all-optical signal processing and optical buffers. Our experimental temporal cavity soliton setup consists of a 100m ring of conventional telecommunications fiber. A CW holding beam is locked at a set detuning from a longitudinal mode of the cavity. Cavity solitons are excited in the ring either via the cross-phase modulation of an external writing pulse, or by direct phase modulation of the holding beam. In Fig. 1 we plot an experimental FROG trace of an isolated cavity soliton sitting on top of the CW background of the holding beam. Once written into the ring the cavity solitons will circulate around the ring indefinitely as long as the holding beam is maintained at the correct detuning. Experimentally we have been able to observe cavity solitons circulating for up to one hour. This very long interaction time has allowed us to observe ultra-weak interactions between adjacent solitons. These interactions are mediated by sound waves generated in the fiber by electrostriction and represent the weakest interactions ever observed between solitons.
Fig 1: FROG trace of a temporal cavity soliton circulating in a 100m ring of standard single-mode fiber. The temporal cavity soliton exists on the finite CW background of the holding beam.
For more details on this work please see:
K. Luo, J. K. Jang, S. Coen, S. G. Murdoch and M. Erkintalo Spontaneous creation and annihilation of temporal cavity solitons in a coherently-driven passive fiber resonator,” Opt. Lett. 40, 3735-3737 (2015)
J. K. Jang, M. Erkintalo, S. Coen, and S. G. Murdoch. “Temporal tweezing of light through the trapping and manipulation of temporal cavity solitons.” Nature communications 6 7370 (2015)
J. K. Jang, M. Erkintalo, S. G. Murdoch, and S. Coen, “Observation of dispersive wave emission by temporal cavity solitons,” Opt. Lett. 39, 5503-5506 (2014)
J. K. Jang, M. Erkintalo, S. G. Murdoch and S. Coen, “Ultraweak long-range interactions of solitons observed over astronomical distances”, Nature Photonics 7, 657 (2013)