摘要
研制了一种用于冷原子重力仪的集成化、低相噪、多通道微波频率综合器。利用锁相环技术,将100 MHz晶振锁定到10 MHz晶振上,改善了100 MHz晶振近端的相位噪声,使输出至后级倍频链路的100 MHz信号的相位噪声同时具备10 MHz及100 MHz晶振的优点。通过搭建超低相噪倍频链路,得到^(87)Rb原子基态跃迁所需的6.834 GHz微波信号。通过互相关法测量得到在频偏为1 Hz和10 kHz处的相位噪声分别为-60 dBc/Hz和-120 dBc/Hz,其频率分辨率为1.42×10^(-6)Hz,并评估了其相位噪声对冷原子重力仪测量分辨率的影响。该微波频综方案具有普适性,可广泛应用于原子钟和干涉仪等量子精密测量领域。
This paper develops a low-phase noise microwave frequency synthesizer for a cold atom gravimeter.The phaselocked loop technique improves the near-end phase noise at the output frequency of the 100 MHz crystal oscillator.The 6.834 GHz microwave signal required for the ground states transition of the ^(87)Rb atom is obtained by building an ultralow-phase-noise multiplier.The measured absolute phase noise performance of the 6.834 GHz signal is -60 dBc/Hz and -120 dBc/Hz at offset frequencies of 1 Hz and 10 kHz,respectively.The frequency resolution is as small as 1.42×10^(-6) Hz.Meanwhile,we investigated the impact of the microwave source’s phase noise on the cold atomic gravimeter’s measurement resolution.The microwave frequency synthesizer is compact and easily expandable to other quantum precision measurement fields such as atomic clocks and atomic interferometers.Objective Microwaves are commonly used in quantum precision measurements,and their frequency,power and phase must be precisely controlled.Atomic clocks,for example,are typically closed-loop locked using frequency hopping or phase tuning.Other experiments,such as measuring electric fields with Rydberg atoms,necessitate driving and adjusting the microwave antenna’s power.For example,in the cold atomic gravimeter,the doppler shift caused by gravity during the free fall of atoms needs to be compensated by scanning the frequency of the Raman laser and the resolution of the frequency tuning will affect the measurement precision.On the other hand,the performance of the microwave source could affect the measurement accuracy of the experiment and the stability of the atomic clock due to the Dick effect.Because of its ultra-low-phase noise performance,aphoto-generated microwave has been widely used in quantum precision measurement.However,due to its complex structure,it is difficult to integrate.This paper develops a miniaturized vehicle-mounted frequency synthesizer with low-phase noise and ultra-high frequency resolution.Methods Based on the phase-locked
作者
欧阳鑫川
胡青青
叶美凤
邓见辽
杨博文
亓航航
肖玲
万金银
成华东
Ouyang Xinchuan;Hu Qingqing;Ye Meifeng;Deng Jianliao;Yang Bowen;Qi Hanghang;Xiao Ling;Wan Jinyin;Cheng Huadong(Key Laboratory of Quantum Optics,Shanghai Institute of Optics and Fine Mechanics,Chinese Academy of Sciences,Shanghai 201800,China;Center of Materials Science and Optoelectronics Engineering,University of Chinese Academy of Sciences,Beijing 100049,China;Advanced Interdisciplinary Technology Research Center,National Innovation Institute of Defense Technology,Beijing 100010,China)
出处
《中国激光》
EI
CAS
CSCD
北大核心
2021年第23期134-140,共7页
Chinese Journal of Lasers
基金
国家自然科学基金(61875215,61727821,11904408)。
关键词
测量与计量
精密测量
微波频综
低相噪
锁相环
冷原子重力仪
measurement and metrology
precision measurement
microwave synthesizer
low phase noise
phase locked loop
cold atomic gravimeter
