Ultimate Parameters of the All-Optical Single-Beam Nonzero Magnetic Field Sensor for Biological Applications

In this letter, we present the results of an investigation of ultimately achievable parameters of an all-optical magnetic field sensor developed for biological applications such as nonzero field magnetoencephalography and magnetocardiography. The scheme performs hyperfine and Zeeman optical pumping, as well as excitation and detection of magnetic resonance, by means of a single laser beam with time-modulated ellipticity. It does not require the use of radio frequency fields, a feature that is essential when creating arrays of sensors. The results of experimental studies allow us to estimate the ultimate sensitivity of the scheme and optimize its optical pumping parameters.