Tesla-scale magnetic field measurement based on Sideband-overlap Zeeman spectroscopy using a functionalized MEMS vapor cell

Accurate measurement of strong magnetic fields in the Tesla range remains a persistent challenge due to calibration drift, nonlinearity, and spatial gradient sensitivity. Here, we present a compact magnetometry approach based on sideband-overlap Zeeman spectroscopy, enabled by a functionalized MEMS cesium vapor cell. The vapor cell features a dual-chamber glass–Si–glass structure with integrated microheaters on the optical window. A first-order electro-optic modulator produces optical sidebands aligned with the σ⁺ and σ− Zeeman-split components of the Cs D1 line under the hyperfine Paschen–Back regime. Magnetic field scanning from zero to Tesla-scale fields enables extraction of the frequency offset between reference and Zeeman-shifted spectra. This frequency shift is directly converted into magnetic field strength using Zeeman spectroscopy in the hyperfine Paschen–Back regime. The method resolves sixteen Zeeman transitions (eight σ+ and eight σ−), allowing measurement of a field strength of 0.6694921 T, with a single-shot resolution of 6.4 μT and a cross-transition repeatability of σB = 8.9 μT (corresponding to 13 ppm at 0.6695 T). In a millimeter-scale sensing volume, the system achieves sub-10 μT repeatability without requiring a uniform bias field. These results indicate that the microfabricated high-field magnetometer can serve as a compact and practical approach for Tesla-range field measurement and pave the way for chip-scale quantum devices.