Kerr soliton microcombs have recently emerged as a prominent topic in integrated photonics and have enabled new horizons for optical frequency metrology. Kerr soliton microcombs, as the name suggests, are based on high-order cubic optical nonlinearity. It is desirable to exploit quadratic photonic materials, namely Pockels materials, for soliton generation and on-chip implementation of 1f–2f comb self-referencing. Such quadratically driven solitons have been proposed theoretically, but have not yet been observed in a nanophotonic platform, despite recent progress in quadratic comb generation in free-space and crystalline resonators. Here, we report photonic-chip-based Pockels microcomb solitons driven by three-wave mixing in an aluminium nitride microring resonator. In contrast to typical Kerr solitons, the Pockels soliton features unity soliton generation fidelity, two-by-two evolution of multi-soliton states, favourable tuning dynamics and high pump-to-soliton conversion efficiency.

Kerr孤子微梳最近已成为集成光子学中的一个突出主题，并为光频率计量学开辟了新的领域。顾名思义，克尔孤子微梳基于高阶三次光学非线性。最好利用二次光子材料，即普克尔斯材料，来产生孤子并在芯片上实现1 f – 2 f梳状自我参照。尽管已经在自由空间和晶体谐振器中产生二次梳状结构方面取得了新进展，但从理论上已经提出了这种二次驱动孤子，但尚未在纳米光子平台中观察到。在这里，我们报告由光波芯片的Pockels微梳孤子，它们由氮化铝微环谐振器中的三波混合驱动。与典型的Kerr孤子相比，Pockels孤子具有统一的孤子生成保真度，多孤子状态的2比2演化，良好的调谐动力学和高的泵到孤子转换效率。