Real-time transition dynamics and stability of chip-scale dispersion-managed frequency microcombs

Abstract

Femtosecond mode-locked laser frequency combs have served as the cornerstone in precision spectroscopy, alloptical atomic clocks, and measurements of ultrafast dynamics. Recently frequency microcombs based on nonlinear microresonators have been examined, exhibiting remarkable precision approaching that of laser frequency combs, on a solid-state chip-scale platform and from a fundamentally different physical origin. Despite recent successes, to date, the real-time dynamical origins and high-power stabilities of such frequency microcombs have not been fully addressed. Here, we unravel the transitional dynamics of frequency microcombs from chaotic background routes to femtosecond mode-locking in real time, enabled by our ultrafast temporal magnifier metrology and improved stability of dispersion-managed dissipative solitons. Through our dispersion-managed oscillator, we further report a stability zone that is more than an order-of-magnitude larger than its prior static homogeneous counterparts, providing a novel platform for understanding ultrafast dissipative dynamics and offering a new path towards high-power frequency microcombs.

Kerr nonlinearity-assisted quadratic microcomb

“…We first consider the case of pure χ (2) nonlinearity by setting γ 1 = γ 2 = γ 12 = γ 21 = 0 and the quasi-phase-matched condition Δk = 0. Our simulations, beginning from noise, are iterated for 0.5 million roundtrips and the results are obtained during a sweep of the laser frequency across the resonance, which is similar to the method commonly Frontiers in Physics frontiersin.org used for the excitation of cavity soliton states in Kerr resonators [26]. Figure 2A shows the temporal evolution and spectral dynamics of the signal field A during the pump frequency scanning process.…”

Integrated Optical Frequency Microcomb Applications

“…Since the different device architectures for generating optical microcombs have already been reviewed in previous literature [11,12,83], here we focus on recent progress after 2018, which has improved the microcomb performance in terms of spectral bandwidth, power consumption, conversion efficiency, and stability. Si3N4 [26,55,89,104,114,135,139,140,150,152], Hydex [56,68,83,112], Si [148], LiNbO3 [93,95,108], AlGaAs [33,88], AlN [98,113], Diamond [85], GaP [92], Ta2O5 [91] Multiple rings 10 5 -10 6 10 2 Yes Si3N4 [149][150][151] Waveguide dispersion in particular is an important parameter that determines the spectral bandwidth of optical microcombs. For optical resonators, their resonance frequencies can be expanded in a Taylor series around the pumped mode as follows [11,12] ( )…”

Applications for optical frequency microcomb chips

“…Since the different device architectures for generating optical microcombs have already been reviewed in previous literature [11,12,83], here we focus on recent progress after 2018, which has improved the microcomb performance in terms of spectral bandwidth, power consumption, conversion efficiency, and stability. No SiO2 [71,145,146], MgF2 [22][23][24]147] Single ring 10 5 -10 7 10 1 -10 3 Yes Si3N4 [26,55,89,104,114,135,139,140,150,152], Hydex [56,68,83,112], Si [148], LiNbO3 [93,95,108], AlGaAs [33,88], AlN [98,113], Diamond [85], GaP [92], Ta2O5 [91] Multiple rings 10 5 -10 6 10 2 Yes Si3N4 [149][150][151] Waveguide dispersion in particular is an important parameter that determines the spectral bandwidth of optical microcombs. For optical resonators, their resonance frequencies can be expanded in a Taylor series around the pumped mode as follows [11,12]  …”

“…[150] Engineering the waveguide dispersion can also improve comb stability. By tapering the waveguide width of a Si3N4 MRR (Figure 6(c)), thus creating group velocity dispersion (GVD) oscillation, the frequency detuning stability zone has been improved by over an order of magnitude relative to microcombs generated by comparable MRRs but with a uniform waveguide width [152].…”