Analysis and suppression of the misalignment error for the pumping laser in the atomic comagnetometer

Area of Science:

• Atomic physics and quantum sensing.
• Development of high-precision measurement instruments.

Background:

• Pumping laser misalignment in atomic comagnetometers (ACM) significantly degrades optical pumping efficiency and overall instrument performance.
• This misalignment affects the polarization of hybrid atomic spin ensembles (electron and nuclear spins), impacting the Allan standard deviation.

Purpose of the Study:

• To establish a steady-state response model for ACMs that incorporates pumping laser misalignment error.
• To propose and validate an in-situ method for evaluating this misalignment.
• To develop and experimentally verify a novel pumping laser alignment technique.

Main Methods:

• Development of a steady-state response model for ACMs considering laser misalignment.
• Proposal of an in-situ evaluation method for pumping laser misalignment.
• Implementation of a laser alignment technique utilizing the second harmonic of a single-beam magnetometer.

Main Results:

• Quantitative analysis demonstrated the detrimental influence of misalignment on pumping efficiency and ACM performance.
• The proposed alignment method resulted in a 19% increase in hybrid atomic spin ensemble polarization.
• The Allan variance at 100s was reduced by approximately 40% compared to the unaligned system.

Conclusions:

• The developed steady-state model accurately describes the impact of laser misalignment.
• The proposed in-situ evaluation and alignment methods effectively mitigate the negative effects of pumping laser misalignment.
• The experimental validation confirms significant improvements in ACM polarization and performance metrics.