Simultaneous excitation of 85Rb and 87Rb isotopes inside a microfabricated vapor cell with double-RF fields for a chip-scale MZ magnetometer

Abstract

We report a novel method adopting two RF fields to simultaneously excite Rb andRb isotopes for an M type atomic magnetometer. The M magnetometer adopts a 6 mm microfabricated vapor cell with natural abundance rubidium and 0.74 amagat nitrogen as buffer gas inside. The excessively broadened magnetic resonance signals of the two rubidium isotopes overlap with each other and cause deterioration in accuracy and sensitivity performance. To solve this problem, a Double-RF Field Method (DRFM) is proposed, which adopts two RF fields with a central frequency ratio of 2:3. Compared with traditional Single-RF Field Method (SRFM), the DRFM reduces the detection error by over 50% and improves the sensitivity by more than 10%. The experiments are conducted at three temperatures and under various static magnetic fields. Theoretical models are also built to discuss the performance improvement of the magnetometer by the DRFM against the SRFM. This method provides a way to improve the performance of chip-scale M atomic magnetometers with low cost natural abundance rubidium.

Research on high sensitivity Mz rubidium laser optically pumped magnetometer

“…Its sensitivity has been greatly improved compared with the traditional light optically pumped magnetometer [3]. Optical pump magnetometer can be divided into rubidium, cesium and helium optical pump magnetometer according to the different core working substances [4][5][6]. This article uses rubidium 87 isotope as the core material.…”