Photonic Chip‐Based High‐Efficiency Soliton Microcombs via Electro‐Optic‐Kerr Synergy

Abstract

Temporal soliton mode‐locking in coherently pumped microcavities provides a promising platform for miniaturized frequency comb systems. While significant progress has been made, achieving high conversion efficiency in such microcombs remains a critical challenge. Soliton generation through pulse pumping has emerged as an effective strategy to improve conversion efficiency. However, the on‐chip integration of pulse generation with dissipative Kerr soliton (DKS) formation within the photonic chip has not yet been realized. Here, we demonstrate a high‐efficiency soliton microcomb by leveraging a synergistic electro‐optic (EO) and Kerr interaction on a hybrid chip‐scale platform. We fabricate an EO comb on a lithium niobate‐on‐insulator (LNOI) platform, delivering a 35.5 GHz repetition rate with broadly tunable center frequencies, which serves as a high‐quality pulse pump. By injecting these pulses into a silicon nitride (SiN) microresonator, their strong, periodic driving field directly initiates and stabilizes a DKS. This EO‐Kerr synergy rigidly phase‐locks the soliton repetition rate to the microwave‐driven EO comb. This deterministic generation process enables a stable, steady‐state optical pump‐to‐soliton conversion efficiency of . This hybrid LNOI‐SiN system establishes a viable pathway toward chip‐scale soliton microcombs with high efficiency, opening up new possibilities for optical communications, precision spectroscopy, and photonic sensing.