With optical spectral marks equally spaced by a frequency in the microwave or the radio frequency domain, optical frequency combs have been used not only to synthesize optical frequencies from microwave references but also to generate ultralow-noise microwaves via optical frequency division. Here, we combine two compact frequency combs, namely, a soliton microcomb and a semiconductor gain-switched comb, to demonstrate low-noise microwave generation based on a novel frequency division technique. Using a semiconductor laser that is driven by a sinusoidal current and injection-locked to microresonator solitons, our scheme transfers the spectral purity of a dissipative soliton oscillator into the subharmonic frequencies of the microcomb repetition rate. In addition, the gain-switched comb provides dense optical spectral emissions that divide the line spacing of the soliton microcomb. With the potential to be fully integrated, the merger of the two chipscale devices may profoundly facilitate the wide application of frequency comb technology.

借助在微波或射频域中的频率均等间隔的光谱标记，光学频率梳不仅用于合成微波参考的光学频率，还用于通过光学频分产生超低噪声的微波。在这里，我们结合了两个紧凑的频率梳，即孤子微梳和半导体增益切换梳，以展示基于新型分频技术的低噪声微波产生。我们的方案使用正弦电流驱动并注入锁定到微谐振器孤子的半导体激光器，将耗散孤子振荡器的光谱纯度转换为微梳重复频率的次谐波频率。此外，增益切换梳提供密集的光谱发射，该光谱发射将孤子微梳的行间距分开。具有完全集成的潜力，两个芯片级器件的合并可以极大地促进频率梳技术的广泛应用。