arXiv:2209.04249 · Physical Review Applied
Single-Beam Room-Temperature Atomic Magnetometer with Large Bandwidth and Dynamic Range
K. K. George Kurian, Sushree S. Sahoo, Perunthiruthy K. Madhu, G Rajalakshmi
Abstract
We present a single-beam atomic magnetometer operating at room temperature for the measurement of ac magnetic fields. The magnetometer functions in the nonlinear regime of magneto-optical rotation of ${}^{85}\mathrm{Rb}$ atomic vapor without any buffer gases. We demonstrate a sensitivity of approximately $0.9\phantom{\rule{0.2em}{0ex}}\mathrm{pT}/\sqrt{\mathrm{Hz}}$ at 2 kHz and a large bandwidth of 24 kHz. The dynamic range of measurement is ${10}^{6}$, making the sensor effective even in Earth's field. We present the signal-to-noise and bandwidth characteristics of the system for both shielded and unshielded modes of operation. Moreover, we perform theoretical analysis for the atom-light system for the single-laser-beam configuration. The effect of light intensity and detuning on the magnetometer is studied theoretically as well as experimentally to understand the strengths and limitations of the technique.