Optical vortex atomic magnetometer

We introduce an atomic magnetometer based on ⁸⁵ Rb atomic sensing in double-pass configuration, which is normally used in Dopplerfree saturation spectroscopy. Both the Zeeman and the Faraday effect take place in our technique. We enhance our magnetometer with an optical vortex (OV) beam contained orbital angular momentum (OAM) state. An advantage of our scheme is the use of a single laser source or a single wavelength. This laser beam can work as both the pump and the probe beam simultaneously. Several parameters such as laser detuning, power, polarization, OAM state, and Rb temperature have been tested in order to optimize the setup. An accuracy of 100 pT in a large scale measurement of a few millitesla can be achieved with our recent setup. Our atomic magnetometer is simple and it has potential applications in quantum technology and even in geological surveys.