Wang Beichen, Morgan Jesse S, Sun Keye, Jahanbozorgi Mandana, Yang Zijiao, Woodson Madison, Estrella Steven, Beling Andreas, Yi Xu
Department of Electrical and Computer Engineering, University of Virginia, Charlottesville, VA, 22904, USA.
Department of Physics, University of Virginia, Charlottesville, VA, 22904, USA.
Light Sci Appl. 2021 Jan 1;10(1):4. doi: 10.1038/s41377-020-00445-x.
Millimetre-wave (mmWave) technology continues to draw great interest due to its broad applications in wireless communications, radar, and spectroscopy. Compared to pure electronic solutions, photonic-based mmWave generation provides wide bandwidth, low power dissipation, and remoting through low-loss fibres. However, at high frequencies, two major challenges exist for the photonic system: the power roll-off of the photodiode, and the large signal linewidth derived directly from the lasers. Here, we demonstrate a new photonic mmWave platform combining integrated microresonator solitons and high-speed photodiodes to address the challenges in both power and coherence. The solitons, being inherently mode-locked, are measured to provide 5.8 dB additional gain through constructive interference among mmWave beatnotes, and the absolute mmWave power approaches the theoretical limit of conventional heterodyne detection at 100 GHz. In our free-running system, the soliton is capable of reducing the mmWave linewidth by two orders of magnitude from that of the pump laser. Our work leverages microresonator solitons and high-speed modified uni-traveling carrier photodiodes to provide a viable path to chip-scale, high-power, low-noise, high-frequency sources for mmWave applications.
毫米波（mmWave）技术因其在无线通信、雷达和光谱学中的广泛应用而持续引发极大关注。与纯电子解决方案相比，基于光子的毫米波产生具有宽带宽、低功耗以及可通过低损耗光纤进行远程传输的特点。然而，在高频情况下，光子系统存在两个主要挑战：光电二极管的功率滚降，以及直接源自激光器的大信号线宽。在此，我们展示了一种新型光子毫米波平台，该平台将集成微谐振器孤子与高速光电二极管相结合，以应对功率和相干性方面的挑战。孤子本质上是锁模的，经测量，通过毫米波拍频信号之间的相长干涉可提供5.8 dB的额外增益，并且绝对毫米波功率接近100 GHz常规外差检测的理论极限。在我们的自由运行系统中，孤子能够将毫米波线宽相对于泵浦激光器的线宽降低两个数量级。我们的工作利用微谐振器孤子和高速改进型单载流子光电二极管，为毫米波应用提供了一条通向芯片级、高功率、低噪声、高频源的可行途径。
