skip to main content

SciTech ConnectSciTech Connect

Title: A plateau in the sensitivity of a compact optically pumped atomic magnetometer

In a compact optically pumped atomic magnetometer (OPAM), there is a plateau in the sensitivity where the dependence of the sensitivity on pumping power is small compared with that predicted by the uniform polarization model. The mechanism that generates this plateau was explained by numerical analysis. The distribution of spin polarization in the alkali metal cell of an OPAM was modeled using the Bloch equation incorporating a diffusion term and an equation for the attenuation of the pump beam. The model was well-fitted to the experimental results for a module with a cubic cell with 20 mm sides and pump and probe beams with 8 mm diameter. On the plateau, strong magnetic response was generated at the regions that were not illuminated directly by the intense pump beam, while at the same time spin polarization as large as 0.5 was maintained due to diffusion of the spin-polarized atoms. Thus, the sensitivity of the magnetometer monitored with a probe beam decreases only slightly with increasing pump beam intensity because the spin polarization under an intense pump beam is saturated. This plateau, which is characteristic of this type of magnetometer using a narrow pump and probe beams, can be used in arraysmore » of magnetometers because it enables stable operation with little sensitivity fluctuation from changes in pump beam power.« less
Authors:
; ; ; ;  [1] ;  [2]
  1. Frontier Research Center, Canon Inc., Ohta-ku, Tokyo, 146-8501 (Japan)
  2. Department of Electrical Engineering, Graduate School of Engineering, Kyoto University, Kyoto, 615-8510 (Japan)
Publication Date:
OSTI Identifier:
22300148
Resource Type:
Journal Article
Resource Relation:
Journal Name: AIP Advances; Journal Volume: 4; Journal Issue: 5; Other Information: (c) 2014 Author(s); Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; 36 MATERIALS SCIENCE; ALKALI METALS; BEAMS; BLOCH EQUATIONS; MAGNETOMETERS; NUMERICAL ANALYSIS; POLARIZATION; PUMPS; SENSITIVITY; SPIN ORIENTATION