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Characterizing current noise of commercial constant-current sources by using an optically pumped rubidium atomic
Ni Zhao1, Lulu Zhang1, Yongbiao Yang1
1State Key Laboratory of Quantum Optics and Quantum Optics Devices and Institute of Opto-Electronics, Shanxi University, Taiyuan 030006, Shanxi Province, China.
The Review of Scientific Instruments
|September 1, 2023
Summary
Researchers developed a new method to measure current noise in constant-current sources (CCS) using atomic magnetometers. The Keysight B2961A demonstrated the lowest current noise, crucial for high-sensitivity atomic magnetometers.
Area of Science:
- Metrology and Scientific Instrumentation
- Atomic Physics and Magnetometry
- Electrical Engineering and Applied Physics
Background:
- Characterizing current noise in constant-current sources (CCS) is vital for precision measurements.
- Optically pumped atomic magnetometers offer high sensitivity but require stable current sources.
- Existing methods for CCS noise characterization may lack sufficient precision for advanced applications.
Purpose of the Study:
- To introduce and validate a novel method for characterizing the current noise of commercial CCS.
- To compare the current noise performance of various commercially available low-noise CCS.
- To establish the relationship between CCS noise and atomic magnetometer sensitivity.
Main Methods:
- Utilized a free-induction-decay (FID) type optically pumped rubidium atomic magnetometer.
- Drove the atomic magnetometer with a radio frequency magnetic field.
- Calibrated the coil constant to convert magnetometer sensitivity into CCS current noise.
Main Results:
- Successfully characterized CCS current noise by leveraging atomic magnetometer sensitivity.
- Identified the Keysight model B2961A as having the lowest current noise among six tested CCS.
- Quantified the noise levels: 36.233 ± 0.022 nA/Hz1/2 (1-25 Hz) and 133.905 ± 0.080 nA/Hz1/2 (1-100 Hz) for the B2961A.
Conclusions:
- The developed method provides an effective way to assess CCS current noise.
- Low-noise CCS are essential for enhancing the performance of high-sensitivity atomic magnetometers.
- This research serves as a reference for advancing precision CCS, metrology, and fundamental physics.
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