Improvement in the signal amplitude and bandwidth of an optical atomic magnetometer via alignment-to-orientation conversion

We evaluated the alignment-to-orientation conversion (AOC) at the cesium D1 line to improve a nonlinear magneto-optical rotation (NMOR) optical atomic magnetometer's signal amplitude and bandwidth. For the 6 S-2(1/2) F = 3 -> 6 P-2(1/2) F' = 4 transition, the AOC-related NMOR achieves a 1.7-fold enhancement in signal amplitude compared to the conventional NMOR, benefiting from narrow linewidth and ultraweak power broadening. Therefore, an effective amplitude-to-linewidth ratio is maintained in the high-laser-power region. This method is beneficial for detecting high-frequency magnetic signals in nuclear magnetic resonance and biomagnetism, as the NMOR magnetometer bandwidth increases with laser power. (C) 2021 Optical Society of America under the terms of the OSA Open Access Publishing Agreement