آزمایشگاه مگنتوفوتونیک

98-021-29902695+ mphlab@sbu.ac.ir

منو

Harmonic detection of magnetic resonance for sensitivity improvement of optical atomic magnetometers

Harmonic detection of magnetic resonance for sensitivity improvement of optical atomic magnetometers
M. Ranjbaran1, M. M. Tehranchi1, 2, S. M. Hamidi1, S. M. H. Khalkhali2
۱Laser and Plasma Research Institute, Shahid Beheshti University, Tehran, Iran
۲Physics Department, Shahid Beheshti University, Tehran, Iran
Journal of Magnetism and Magnetic Materials

 

Abstract
Highly sensitive atomic magnetometers use optically detected magnetic resonance of atomic spins to measure extremely weak magnetic field changes. The magnetometer sensitivity is directly proportional to the ratio of intensity to line-shape of the resonance signal. To obtain narrower resonance signal, we implemented harmonic detection of magnetic resonance method in Mx configuration. The nonlinear spin polarization dynamics in detection of the
higher harmonics were employed in phenomenological Bloch equations. The measured and simulated harmonic components of the resonance signals in frequency domain yielded significantly narrower line-width accompanying much improved sensitivity. Our results confirm the sensitivity improvement by a factor of two in optical atomic magnetometer via second harmonic signal which can open a new insight in the weak magnetic field measurement system design.