Integrated Soliton Microcombs beyond the Turnkey Limit

Self-injection locking enables integrated soliton microcombs with turnkey initiation and improved coherence, but it also pins the pump close to resonance, limiting the access to large detuning for broader combs. Here, we use an auxiliary resonator to dynamically hybridize the pump mode, enabling adiabatic access to a far-detuned soliton regime while preserving linewidth narrowing. In a 25-GHz soliton microcomb, the 3-dB bandwidth increases from 17.1 to 26.8 nm, with an added control degree of freedom for near-orthogonal frequency tuning. These results reveal a pathway to broader integrated soliton microcombs beyond the turnkey limit.