US 11,754,601 B2
Measuring frequency of microwave signal
Jianyong Hu, Shanxi (CN); Ruiyun Chen, Shanxi (CN); Chengbing Qin, Shanxi (CN); Guofeng Zhang, Shanxi (CN); Jie Ma, Shanxi (CN); Liantuan Xiao, Shanxi (CN); and Suotang Jia, Shanxi (CN)
Assigned to SHANXI UNIVERSITY, Shanxi (CN)
Filed by SHANXI UNIVERSITY, Shanxi (CN)
Filed on Dec. 21, 2020, as Appl. No. 17/128,206.
Claims priority of application No. 202010435638.3 (CN), filed on May 21, 2020.
Prior Publication US 2021/0364559 A1, Nov. 25, 2021
Int. Cl. G01R 23/02 (2006.01); G01R 23/16 (2006.01)
CPC G01R 23/02 (2013.01) [G01R 23/16 (2013.01)] 11 Claims
OG exemplary drawing
 
1. A frequency measurement method of a microwave signal, comprising:
generating, when a light source irradiates an electro-optical crystal disposed in a microwave electric field, to-be-detected emergent light under an action of the electro-optical crystal, wherein a wave function of the to-be-detected emergent light is periodically modulated with a specific oscillation frequency of the microwave electric field;
inputting the to-be-detected emergent light into a polarization beam splitter;
inputting an output of the polarization beam splitter into an attenuator to attenuate the to-be-detected emergent light to be at a single-photon level;
detecting, by a single-photon detector, the to-be-detected emergent light to obtain a detection result of the single-photon detector, wherein the detection result comprises an arrival time of a photon of the to-be-detected emergent light; and
determining a frequency of the microwave signal in the microwave electric field based on the detection result of the single-photon detector and a Fourier transform algorithm,
wherein generating the to-be-detected emergent light under the action of the electro-optical crystal comprises:
generating, based on a polarization modulation, by placing a Faraday reflector after the electro-optical crystal, the to-be-detected emergent light when the light source passes through the electro-optical crystal twice.