Solitons,the distinct balance between nonlinearity and dispersion,provide a route toward ultrafast electromagnetic pulse shaping,high-harmonic generation,real-time image processing,and RF photonic communications.Here ...Solitons,the distinct balance between nonlinearity and dispersion,provide a route toward ultrafast electromagnetic pulse shaping,high-harmonic generation,real-time image processing,and RF photonic communications.Here we uniquely explore and observe the spatio-temporal breather dynamics of optical soliton crystals in frequency microcombs,examining spatial breathers,chaos transitions,and dynamical deterministic switching–in nonlinear measurements and theory.To understand the breather solitons,we describe their dynamical routes and two example transitional maps of the ensemble spatial breathers,with and without chaos initiation.We elucidate the physical mechanisms of the breather dynamics in the soliton crystal microcombs,in the interaction plane limit cycles and in the domain-wall understanding with parity symmetry breaking from third-order dispersion.We present maps of the accessible nonlinear regions,the breather frequency dependences on third-order dispersion and avoided-mode crossing strengths,and the transition between the collective breather spatio-temporal states.Our range of measurements matches well with our first-principles theory and nonlinear modeling.To image these soliton ensembles and their breathers,we further constructed panoramic temporal imaging for simultaneous fast-and slow-axis two-dimensional mapping of the breathers.In the phasedifferential sampling,we present two-dimensional evolution maps of soliton crystal breathers,including with defects,in both stable breathers and breathers with drift.Our fundamental studies contribute to the understanding of nonlinear dynamics in soliton crystal complexes,their spatio-temporal dependences,and their stability-existence zones.展开更多
Frequency microcombs with microwave and millimeter-wave repetition rates provide a compact solution for coherent communication and information processing.The implementation of these microcombs using a CMOS-compatible ...Frequency microcombs with microwave and millimeter-wave repetition rates provide a compact solution for coherent communication and information processing.The implementation of these microcombs using a CMOS-compatible platform further paves the way for large-scale photonic integration and modularity.Here,we demonstrate free-running soliton microcombs with K-band repetition rates with very low phase noise over a 4 GHz pump detuning range reaching−117(−123)dBc/Hz at 10 kHz offset for a 19.7(10)GHz carrier without active pump stabilization,exceeding commercial electronic microwave oscillators at frequency offsets above 40 kHz.The minimum laser noise to soliton microwave signal transduction factor observed is−73dB.This noise performance is achieved using a hybridized dual-mode for soliton generation to achieve passive thermal stabilization and minimal soliton spectrum shift from prior Raman scattering and dispersive wave formation.We further examine the locking of the repetition rate to an external ultrastable photonic oscillator to illustrate the feasibility of phase noise suppression below the thermorefractive noise limits of microresonator frequency combs.展开更多
基金supported by the Office of Naval Research and the Office of Naval Research MURI program,DARPA,National Science Foundation,and Lawrence-Livermore National Laboratory.
文摘Solitons,the distinct balance between nonlinearity and dispersion,provide a route toward ultrafast electromagnetic pulse shaping,high-harmonic generation,real-time image processing,and RF photonic communications.Here we uniquely explore and observe the spatio-temporal breather dynamics of optical soliton crystals in frequency microcombs,examining spatial breathers,chaos transitions,and dynamical deterministic switching–in nonlinear measurements and theory.To understand the breather solitons,we describe their dynamical routes and two example transitional maps of the ensemble spatial breathers,with and without chaos initiation.We elucidate the physical mechanisms of the breather dynamics in the soliton crystal microcombs,in the interaction plane limit cycles and in the domain-wall understanding with parity symmetry breaking from third-order dispersion.We present maps of the accessible nonlinear regions,the breather frequency dependences on third-order dispersion and avoided-mode crossing strengths,and the transition between the collective breather spatio-temporal states.Our range of measurements matches well with our first-principles theory and nonlinear modeling.To image these soliton ensembles and their breathers,we further constructed panoramic temporal imaging for simultaneous fast-and slow-axis two-dimensional mapping of the breathers.In the phasedifferential sampling,we present two-dimensional evolution maps of soliton crystal breathers,including with defects,in both stable breathers and breathers with drift.Our fundamental studies contribute to the understanding of nonlinear dynamics in soliton crystal complexes,their spatio-temporal dependences,and their stability-existence zones.
基金Defense Advanced Research Projects Agency(HR001122C0017).
文摘Frequency microcombs with microwave and millimeter-wave repetition rates provide a compact solution for coherent communication and information processing.The implementation of these microcombs using a CMOS-compatible platform further paves the way for large-scale photonic integration and modularity.Here,we demonstrate free-running soliton microcombs with K-band repetition rates with very low phase noise over a 4 GHz pump detuning range reaching−117(−123)dBc/Hz at 10 kHz offset for a 19.7(10)GHz carrier without active pump stabilization,exceeding commercial electronic microwave oscillators at frequency offsets above 40 kHz.The minimum laser noise to soliton microwave signal transduction factor observed is−73dB.This noise performance is achieved using a hybridized dual-mode for soliton generation to achieve passive thermal stabilization and minimal soliton spectrum shift from prior Raman scattering and dispersive wave formation.We further examine the locking of the repetition rate to an external ultrastable photonic oscillator to illustrate the feasibility of phase noise suppression below the thermorefractive noise limits of microresonator frequency combs.
