Dual-beam room-temperature atomic magnetometer with high sensitivity and large dynamic range

We demonstrate a dual-beam high-sensitivity room-temperature atomic magnetometer (AM) with a large dynamic range based on a nonlinear magneto-optical rotation (NMOR) enhancing scheme. Using an inelastic wave-mixing laser, we find significant NMOR signal enhancement compared with a single-beam scheme under the same far-detuned operation conditions. This dual-beam scheme is shown to operate well in the regime of lower laser intensity and off-resonance detuning. The best sensitivity achieved is 20 fT/Hz(1/2) with a bandwidth of 2 kHz, substantially greater than common spin-exchange relaxation-free AMs. This provides a way to develop low-power, inexpensive miniaturized AMs for wide application.

Automated summary

We present a dual-beam high-sensitivity atomic magnetometer (AM) that operates at room temperature and has a large dynamic range. By using a nonlinear magneto-optical rotation (NMOR) enhancing scheme with an inelastic wave-mixing laser, we achieve significant signal enhancement compared to a single-beam scheme. The dual-beam scheme performs well at lower laser intensities and off-resonance detuning, delivering a sensitivity of 20 fT/Hz(1/2) and a bandwidth of 2 kHz, surpassing traditional spin-exchange relaxation-free AMs. This opens up possibilities for the development of low-power and cost-effective miniaturized AMs for various applications.