From order to chaos in a chip-scale Kerr parametric oscillator
Luca O. Trinchão,
Juan Diego Mazo-Vásquez,
Miguel Nienstedt,
Luiz Peres,
Julius Gohsrich,
Eduardo S. Gonçalves,
Alekhya Ghosh,
Arghadeep Pal,
Laís Fujii dos Santos, et al.
Integrated photonics has enabled a wide class of chip-scale light sources and quantum technologies. Within this field, microresonator-based degenerate optical parametric oscillators (DOPOs) have gained prominence. Above a critical power threshold, these systems undergo spontaneous symmetry breaking to settle into one of two stable, π-phase-shifted states -- a mechanism successfully used for quantum random number generation and photonic Ising machines. Here, we show that DOPOs based on the Kerr nonlinearity host a significantly broader range of nonlinear dynamics than previously explored. Using a silicon nitride microring resonator, we experimentally identify Hopf bifurcations that trigger a transition from stationary operation to self-sustained oscillations at MHz frequencies. By adjusting pump detunings and powers, we achieve turnkey control over these oscillatory regimes, navigating the system between stable binary states and periodic limit cycles. Furthermore, we report the experimental observation of period-doubling bifurcations, which numerical simulations reveal as the precursor to a cascading instability culminating in chaos at elevated pump powers. Our results establish a framework for controlling nonlinear instabilities in chip-scale parametric oscillators, with applications in programmable photonic hardware and dynamical optical computing.
Vectorial light in Fabry-Pérot resonators in the normal-dispersion regime
Graeme N. Campbell,
Lewis Hill,
Pascal Del'Haye,
Gian-Luca Oppo
Physical Review A
113
043505
(2026)
| Journal
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The ranges of existence and stability of dark cavity-soliton stationary states in a Fabry-Pérot resonator with a Kerr nonlinear medium, vectorial polarization components, and normal dispersion are determined. The Fabry-Pérot configuration introduces nonlocal coupling that shifts the cavity detuning by the round-trip average power of the intracavity field. When compared with ring resonators, nonlocal coupling leads to strongly detuned dark cavity solitons that exist over a wide range of detunings. We study symmetry breaking between fields of opposite circular polarization characterized by a codimension-2 bifurcation point unique to the regime of normal group velocity dispersion. We show the spontaneous formation of regular dark soliton crystals separated by Turing patterns of alternating polarization via ‘‘self-crystallization’’ due to long-range interactions. Frequency combs of dark soliton crystals of two orthogonal polarizations in Fabry-Pérot resonators display three separate components corresponding to the cavity repetition rate, the wavelength of the periodic pattern, and the soliton lattice spacing. The system also displays the formation of stationary and dynamical vectorial dark-bright solitons. These solutions are different from previous realizations with bichromatic driving in ring resonators, are composed of locked switching fronts, and can undergo Hopf bifurcations when scanning the detuning. Interacting oscillating dark-bright solitons display antiphase dynamics that changes first into quasiperiodic oscillations and then into in-phase dynamics when increasing the cavity length.
Octave-spanning frequency comb from a single-diode-pumped 1 GHz Ti:sapphire laser
Ewan Allan,
Abdullah Alabbadi,
Pablo Castro-Marín,
Hanna Ostapenko,
Pascal Del'Haye,
Derryck T. Reid
Broadband frequency combs with mode spacings of 1 GHz provide a valuable resource for optical frequency metrology and astrophotonics. Significant average powers are often needed to reach the pulse energies required for supercontinuum generation at 1 GHz repetition rates, putting this beyond the reach of most simple ultrafast lasers. Here, by using dispersion-engineered Si₃N₄ waveguides, we report octave-spanning comb generation from 539 to 1078 nm (−20 dB bandwidth) pumped with a three-element 1 GHz Ti:sapphire laser powered by a single laser diode. Laser repetition-rate stability of 790 mHz is achieved over a 1-hour duration, and carrier-envelope-offset control and stabilization to a single-frequency cw laser is presented. The system offers a simple route to a coherent, broadband supercontinuum spanning the visible to the near-infrared, with potential as an enabling technology for optical frequency metrology, quantum timekeeping, and astrophysical spectrograph calibration.
Color symmetry breaking in a nonlinear optical microcavity
Luca O. Trinchão,
Alekhya Ghosh,
Arghadeep Pal,
Haochen Yan,
Toby Bi,
Shuangyou Zhang,
Nathalia B. Tomazio,
Flore K. Kunst,
Lewis Hill, et al.
Spontaneous symmetry breaking leads to diverse phenomena across the natural sciences, from the Higgs mechanism in particle physics to superconductors and collective animal behavior. In photonic systems, the symmetry of light states can be broken when two optical fields interact through the Kerr nonlinearity, as shown in early demonstrations with counterpropagating and cross-polarized modes. Here, we report the first observation of color symmetry breaking in an integrated silicon nitride microring, where spontaneous power imbalance arises between optical mode at different wavelengths, mediated by the Kerr effect. The threshold power for this effect is as low as 19 mW. By examining the system's homogeneous states, we further demonstrate a Kerr-based nonlinear activation-function generator that produces sigmoid-, quadratic-, and leaky-ReLU-like responses. These findings reveal previously unexplored nonlinear dynamics in dual-pumped Kerr resonators and establish new pathways towards compact, all-optical neuromorphic circuits.
