Vector Magnetometry with Microwave-Assisted Optical Pumping in Warm Rubidium Vapor

Vector magnetometers are used in areas such as spacecraft navigation and bio-magnetism. The precision and calibration of many vector magnetometers depend on external field sources and additional instrumentation, whose stability may drift. I describe a vector magnetometry method using microwave-assisted optical pumping, in which a microwave field resonant to the ground state hyperfine splitting of 87Rb pumps an ensemble of warm rubidium vapor, in addition to a strong optical pump beam, and a weaker optical probe beam. The proposed method allows us to detect fields in the in the tens of mT regime and more importantly, the direction of the DC magnetic field relative to the microwave field. I present theoretical details as well as preliminary data demonstrating measurements of a DC magnetic field. These measurements were taken when the DC field was aligned at various angles relative to the microwave magnetic field alignment. I compare theoretical and experimental differences in the measurements.