Close-Loop Bell-Bloom Magnetometer with Amplitude Modulation  

作　　者：黄海超 董海峰 郝慧杰 胡旭阳 

机构地区：[1]School of Instrumentation Science and Opto-Electronies Engineering,Beihang University

出　　处：《Chinese Physics Letters》2015年第9期174-177,共4页中国物理快报（英文版）

基　　金：Supported by the National Natural Science Foundation of China under Grant Nos 61273067 and 61074171;the National Basic Research Program of China under Grant No 2012CB934104

摘　　要：A high sensitive optical amplitude modulation magnetometer is investigated and demonstrated experimentally. We build an experimental platform for the atomic magnetometer and configure it as a Bell-Bloom magnetometer with amplitude modulation of 50% duty cycle square waveform. The open-loop input-output model is deduced from the Bloch equation and is verified experimentally. Instead of locking the frequency by using a voltage control oscillator, we realize a closed loop using the coils to generate a feedback field which avoids the stringent require- ment of a high resolution frequency meter and markedly expands the dynamic range as well as the bandwidth. We realize an open loop sensitivity of 0.8pT/Hz1/2 at 20 Hz using a single light beam, which exceeds that of the state-of-the-art Bell-Bloom magnetometers, and the corresponding closed loop sensitivity is 1.2 pT/Hz1/2.A high sensitive optical amplitude modulation magnetometer is investigated and demonstrated experimentally. We build an experimental platform for the atomic magnetometer and configure it as a Bell-Bloom magnetometer with amplitude modulation of 50% duty cycle square waveform. The open-loop input-output model is deduced from the Bloch equation and is verified experimentally. Instead of locking the frequency by using a voltage control oscillator, we realize a closed loop using the coils to generate a feedback field which avoids the stringent require- ment of a high resolution frequency meter and markedly expands the dynamic range as well as the bandwidth. We realize an open loop sensitivity of 0.8pT/Hz1/2 at 20 Hz using a single light beam, which exceeds that of the state-of-the-art Bell-Bloom magnetometers, and the corresponding closed loop sensitivity is 1.2 pT/Hz1/2.

关 键 词：Close-Loop Bell-Bloom Magnetometer with Amplitude Modulation 

分 类 号：TH763.1[机械工程—仪器科学与技术]