单光子微波光子学

Single-photon microwave photonics

伴随着微波光子学技术的迅速发展,超低功率下的高速微波光子信号检测、处理是一个限制微波光子应用领域的主要难点.考虑到单光子探测器具有超微弱光信号检测能力的同时还具有极低的时间抖动特性,将单光子检测与经典微波光子处理技术相结合是一种突破上述难点的潜在解决方案.基于此,本文提出了一种单光子微波光子系统.该系统使用单光子信号作为载波,通过微波强度改变光子探测几率,再通过单光子探测器得到光子探测几率复原微波信号.该系统成功实现了对单光子强度的微波光子信号进行滤波、移相的操作,而且系统的处理速度仅由单光子探测器时间抖动决定.此外,得益于系统所使用的信号恢复技术,该系统具有的优秀的抗干扰能力能够有效滤除噪声.该系统展示了一个微波光子学和量子光学学科交叉的范例,为之后量子微波光子学的发展奠定基础.

With the rapid development of microwave photonics technology, high-speed processing and ultra-weak signal detection capability have become the main bottlenecks in many applications. Thanks to the ultraweak signal detection capability and the extremely low timing jitter properties of single-photon detectors, the combination of single-photon detection and classical microwave photonics technology may provide a solution to break the above bottlenecks. In this paper, we first report a novel concept of singlephoton microwave photonics(SP-MWP), a SP-MWP signal processing system with phase shifting and frequency filtering functionalities is demonstrated based on a superconducting nanowire single photon detector(SNSPD) and a successive time-correlated single photon counting(TCSPC) module.Experimental results show that an ultrahigh optical sensitivity down to-100 d Bm has been achieved,and the signal processing bandwidth is only limited by the timing jitter of single-photon detectors. In the meantime, the proposed system demonstrates an ultrahigh anti-interference capability, only the signal which is phase locked by the trigger signal in TCSPC can be extracted from the detected signals combining with noise and strong interference. The proposed SP-MWP concept paves a way to a novel interdisciplinary field of microwave photonics and quantum mechanism, named by quantum microwave photonics.