ABSTRACT Microresonator‐based Kerr frequency combs (microcombs) are key platforms for compact, low‐noise photonic microwave generation, especially at the quiet point (QP), where the repetition‐rate phase noise is suppressed by the balance of Raman self‐frequency shift and dispersive wave (DW) recoil. However, due to polarization‐dependent temperature sensitivities in most multimode microcavities, accurate prediction and stable access to the QP remain challenging. Here, a temperature‐dependent DW‐interaction mechanism governing the QP evolution and modulating the soliton phase noise is explored. By modeling DW interactions between orthogonally polarized mode families with different thermo‐optic coefficients, it is demonstrated that temperature‐induced DW shifts lead to an additional soliton recoil and generate a secondary DW. Based on a self‐developed crystalline microresonator, QP disturbance is experimentally analyzed, and a QP‐recovery strategy is proposed, achieving a low phase noise of −140.5 dBc Hz −1 at 10 kHz offset and sustaining this level across a wide temperature range. This work advances the active control of DW interactions that enhance QP accessibility in complex temperature environments, enabling the ultra‐low‐noise deployable soliton microwave generation method based on multimode microresonators.
Zhang et al. (Fri,) studied this question.