Hyun Minji, Ahn Changmin, Na Yongjin, Chung Hayun, Kim Jungwon
School of Mechanical and Aerospace Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, Korea.
Department of Electronics and Information Engineering, Korea University, Sejong, 30019, Korea.
Nat Commun. 2020 Jul 22;11(1):3667. doi: 10.1038/s41467-020-17460-6.
There has been remarkable progress in generating ultralow-noise microwaves from optical frequency combs in the last decade. While a combination of techniques has enabled tens to hundreds of attoseconds residual jitter in microwave extraction, so far most of research efforts have been focused on extracting single-tone microwaves from combs; there has been no study on the noise properties of photocurrent pulses directly extracted from the photodiode. Here, we reveal that the residual jitter between optical pulses and rising edges of photocurrent pulses can be in the tens of attoseconds regime. The rising-edge jitter is much lower than the falling-edge jitter, and further, this ultralow rising-edge jitter could be obtained by both p-i-n and (modified-)uni-travelling-carrier photodiodes. This finding can be directly used for various edge-sensitive timing applications, and further shows the potential for ultrahigh-precision timing using silicon-photonic-integrable on-chip p-i-n photodiodes.
在过去十年中，利用光学频率梳产生超低噪声微波取得了显著进展。虽然多种技术的结合已使微波提取中的残余抖动达到数十至数百阿秒，但到目前为止，大多数研究工作都集中在从频率梳中提取单音微波；尚未有关于直接从光电二极管提取的光电流脉冲噪声特性的研究。在此，我们揭示了光脉冲与光电流脉冲上升沿之间的残余抖动可处于数十阿秒的范围。上升沿抖动远低于下降沿抖动，而且，p-i-n和（改进型）单载流子光电二极管均可实现这种超低上升沿抖动。这一发现可直接用于各种对边缘敏感的定时应用，并进一步显示了使用硅光子集成片上p-i-n光电二极管实现超高精度定时的潜力。
