An all-optical phase detector by amplitude modulation of the local field in a Rydberg atom-based mixer

• Published in: Chinese physics B Vol. 31; no. 9; pp. 90703 - 288
• Main Authors: Liu, Xiu-Bin, Jia, Feng-Dong, Zhang, Huai-Yu, Mei, Jiong, Liang, Wei-Chen, Zhou, Fei, Yu, Yong-Hong, Liu, Ya, Zhang, Jian, Xie, Feng, Zhong, Zhi-Ping
• Format: Journal Article
• Language: English
• Published: Chinese Physical Society and IOP Publishing Ltd 01.08.2022; Institute of Physics,Chinese Academy of Sciences,Beijing 100190,China%National Time Service Centre,Chinese Academy of Sciences,Xi'an 710600,China,University of Chinese Academy of Sciences,Beijing 100049,China%Institute of Nuclear and New Energy Technology,Collaborative Innovation Center of Advanced Nuclear Energy Technology,Key Laboratory of Advanced Reactor Engineering and Safety of Ministry of Education,Tsinghua University,Beijing 100084,China%School of Physical Sciences,University of Chinese Academy of Sciences,Beijing 100049,China; CAS Center for Excellence in Topological Quantum Computation,University of Chinese Academy of Sciences,Beijing 100190,China; School of Physical Sciences,University of Chinese Academy of Sciences,Beijing 100049,China%School of Physical Sciences,University of Chinese Academy of Sciences,Beijing 100049,China
• Subjects: amplitude modulation; electromagnetically induced transparency; micorwave; phase detector; quantum sensor; Rydberg atoms; amplitude modulation; phase detector; micorwave; electromagnetically induced trans-parency; Rydberg atoms; quantum sensor
• ISSN: 1674-1056
• DOI: 10.1088/1674-1056/ac6dbb

Recently, a Rydberg atom-based mixer was developed to measure the phase of a radio frequency (RF) field. The phase of the signal RF (SIG RF) field is down-converted directly to the phase of a beat signal created by the presence of a local RF (LO RF) field. In this study, we propose that the Rydberg atom-based mixer can be converted to an all-optical phase detector by amplitude modulation (AM) of the LO RF field; that is, the phase of the SIG RF field is related to both the amplitude and phase of the beat signal. When the AM frequency of the LO RF field is the same as the frequency of the beat signal, the beat signal will further interfere with the AM of the LO RF field inside the atom, and then the amplitude of the beat signal is related to the phase of the SIG RF field. The amplitude of the beat signal and the phase of the SIG RF field show a linear relationship within the range of 0 to π /2 when the phase of the AM is set with a difference π /4 from the phase of the LO RF field. The minimum phase resolution can be as small as 0.6° by optimizing the experimental conditions according to a simple theoretical model. This study will expand and contribute to the development of RF measurement devices based on Rydberg atoms.