# Proof of the feasibility of a nanocell-based wide-range optical magnetometer

## TL;DR

This paper demonstrates a nanocell-based optical magnetometer capable of measuring magnetic fields from 40 to 200 mT with high precision, using simple electronic components, and suggests it can operate effectively at higher fields in the hyperfine Paschen-Back regime.

## Contribution

It introduces a novel nanocell-based scalar magnetometry scheme utilizing derivative reflection spectroscopy and low-cost electronics, achieving accurate measurements in a wide magnetic field range.

## Key findings

- Measurement variation under 5% in 40-200 mT range
- Uses inexpensive Arduino and Raspberry Pi for control and data processing
- Potential to operate accurately above 500 mT in hyperfine Paschen-Back regime

## Abstract

We present an experimental scheme performing scalar magnetometry based on the fitting of Rb D$_2$ line spectra recorded by derivative selective reflection spectroscopy from an optical nanometric-thick cell. To demonstrate its efficiency, the magnetometer is used to measure the inhomogeneous magnetic field produced by a permanent neodimuim-iron-boron alloy ring magnet at different distances. The computational tasks are realized by relatively cheap electronic components: an Arduino Due board for the external control of the laser and acquisition of spectra, and a Raspberry Pi computer for the fitting. The coefficient of variation of the measurements remains under $5\%$ in the magnetic field range of 40 - 200 mT, limited only by the size of the oven and translation stage used in our experiment. The proposed scheme is expected to operate with a high measurement precision also for stronger magnetic fields ($>500~$mT), in the hyperfine Paschen-Back regime, where the evolution of the atomic transitions can be calculated with a high accuracy.