Alignment-Based Optically Pumped Magnetometer Using a Buffer-Gas Cell

Alignment-based optically pumped magnetometers (OPMs) are capable of measuring oscillating magnetic fields with high sensitivity in the $\mathrm{fT}/\sqrt{\mathrm{Hz}}$ range. Until now, alignment-based have only used paraffin-coated vapour cells to extend spin relaxation lifetimes alkali vapour. The drawback these is that they hand blown and therefore time intensive, somewhat unreliable, produce. Buffer-gas cells, on other hand, can be manufactured a mass scale using microfabrication techniques. In this work we use hand-blown but our methods also apply microfabricated buffer-gas cells. We present first demonstration an magnetometer cell containing caesium (Cs) nitrogen (${\mathrm{N}}_{2}$) buffer gas. OPM operated at $55{\phantom{\rule{0.1em}{0ex}}}^{\ensuremath{\circ}}\mathrm{C}$ achieve $325\phantom{\rule{0.2em}{0ex}}\mathrm{fT}/\sqrt{\mathrm{Hz}}$ 10 kHz 800 Hz bandwidth. uses single low-power laser beam for optical pumping probing could potentially allow more rapid commercialization radio-frequency OPMs, due robustness one-beam geometry.