Microwave Quantum Photonics

Juan José García‐Ripoll

Tengfei Hao, Ye Yang, Yaqing Jin +5 more

By combing photonics and radiofrequency (RF) engineering, microwave photonics has been widely studied in the past few decades for the generation, processing, control and distribution of microwave and RF signals using photonic techniques. In parallel with the continuous hot research on classic microwave photonic systems, cross research between microwave photonics and other disciplines is also a promising research spot for scientists in this area. Here we review emerging advances in recent years in cross research between microwave photonics and quantum technology, i.e., quantum microwave photonics that harnessing quantum technology to achieve features or functions that are very complex or even not possible using traditional microwave photonic technology and vice versa. Key motivations of quantum microwave photonics are discussed. The basic operation principle of the quantum single-photon detection scheme, which is the main building block of current quantum microwave photonic systems, is provided. Selected recent advances, including weak microwave signal detection, microwave photonic phase shifting and filtering, nonlocal frequency-to-time mapping, RF compressed sensing, and quantum key distribution, are summarized. Challenges and future prospects of quantum microwave photonics are also discussed.

Xinghua Li, Yifan Guo, Xiao Xiang +6 more

As one of the most fundamental functionalities of microwave photonics, microwave frequency mixing plays an essential role in modern radars and wireless communication systems. However, the commonly utilized intensity modulation in the systems often leads to inadequate spurious-free dynamic range (SFDR) for many sought-after applications. Quantum microwave photonics technique offers a promising solution for improving SFDR in terms of higher-order harmonic distortion. In this paper, we demonstrate two types of quantum microwave photonic mixers based on the configuration of the intensity modulators: cascade-type and parallel-type. Leveraging the nonlocal RF signal encoding capability, both types of quantum microwave photonic mixers not only exhibit the advantage of dual-channel output but also present significant improvement in SFDR. Specifically, the parallel-type quantum microwave photonic mixer achieves a remarkable SFDR value of 113.6 dB.Hz1/2, which is 30 dB better than that of the cascade-type quantum microwave photonic mixer. When compared to the classical microwave photonic mixer, this enhancement reaches a notable 53.6 dB at the expense of 8 dB conversion loss. These results highlight the superiority of quantum microwave photonic mixers in the fields of microwave and millimeter-wave systems. Further applying multi-photon frequency entangled sources as optical carriers, the dual-channel microwave frequency conversion capability endowed by the quantum microwave photonic mixer can be extended to enhance the performance of multiple-paths microwave mixing which is essential for radar net systems.

Thomas P. Pearsall

Xinghua Li, Yifan Guo, Xiao Xiang +7 more

Microwave frequency mixing is a fundamental functionality in microwave photonics, playing a crucial role in modern radar and wireless communication systems. Classical microwave photonic mixers require both the radio frequency (rf) signal and the local oscillator to be loaded onto the same optical light source, thereby impeding their capability in the context of distributed microwave systems. Using time-energy--entangled biphotons as the optical carrier, the quantum microwave photonic (QMWP) mixer offers a promising solution for attaining nonlocal mixing and surmounting such limitations. In this paper, we explore two types of QMWP mixer based on the configuration of the intensity modulators: cascade type and parallel type. Both QMWP mixers feature the properties of high linearity and dual outputs, with their spurious-free dynamic ranges being identical to that of the equivalent classical microwave photonic mixer. Specifically, the parallel-type QMWP mixer can nonlocally mix two physically separated rf signals, demonstrating its superiority in distributed microwave and millimeter-wave radar systems. Further, by application of multiphoton frequency-entangled sources as optical carriers, the nonlocal microwave frequency conversion capability endowed by the QMWP mixer can be extended to enhance the performance of multiple-path microwave mixing, which is essential for radar net systems.

Thomas P. Pearsall