Using the Resonant Faraday Effect to Probe External Magnetic Fields
Published:
Abstract
The Faraday effect, a magneto-optic phenomenon induced by circular birefringence, results in the rotation of the polarization plane as light passes through a medium. This study explores the possibility of applying the resonant Faraday effect to probe the polarization dynamics of helium-3 atoms in a high-pressure hybrid Spin Exchange Optical Pumping (SEOP) cell containing helium-3, rubidium, potassium, and nitrogen gases.For this purpose, a setup utilizing polarization modulation ellipsometry was implemented to measure small rotations of linearly polarized light.
To investigate the sensitivity of the system, a potassium reference cell was placed in a uniform magnetic field and frequency scans across the potassium D2 line (766.7 nm) over a range of 10 GHz were performed using a tunable diode laser.
Preliminary measurements at magnetic field strengths between 4–6 G yielded polarization rotations at resonance of approximately 25-130 μrad at 500 nW. These results are in good agreement with previously published data. In the next step, we plan to improve the system sensitivity by studying the Faraday rotation with respect to magnetic field changes using a frequency stabilized laser. Progress on system performance and sensitivity will be presented.