Herriott-cavity-assisted all-optical atomic vector magnetometer

Abstract

We report an all-optical atomic vector magnetometer using dual Bell-Bloom optical pumping beams in a Rb vapor cell. This vector magnetometer consists of two orthogonal optical pumping beams, with amplitude modulations at 85 Rb and 87 Rb Larmor frequencies respectively. We simultaneously detect atomic signals excited by these two pumping beams using a single probe beam in the third direction, and extract the field orientation information using the phase delays between the modulated atomic signals and the driving beams. By adding a Herriott cavity inside the vapor cell, we improve the magnetometer sensitivity. We study the performance of this vector magnetometer in a magnetic field ranging from 100 mG to 500 mG, and demonstrate a field angle sensitivity better than 10 µrad/Hz 1/2 above 10 Hz.

Herriott-Cavity-Assisted Closed-Loop Xe Isotope Comagnetometer

“…The Herriott cavity used in this paper consists of two cylindrical mirrors with a curvature of 100 mm, a diameter of 12.7 mm, a thickness of 2.5 mm, a relative angle between symmetrical axes of 52 • , and a separation of 19.3 mm [24,28]. The cavity mirrors are anodic bonded [28] to a piece of silicon wafer with a thickness of 0.5 mm.…”

“…The Herriott cavity used in this paper consists of two cylindrical mirrors with a curvature of 100 mm, a diameter of 12.7 mm, a thickness of 2.5 mm, a relative angle between symmetrical axes of 52 • , and a separation of 19.3 mm [24,28]. The cavity mirrors are anodic bonded [28] to a piece of silicon wafer with a thickness of 0.5 mm. During the bonding process, the mirrors are held at the designed positions on the silicon piece using a ceramic mould, which limits the mirror misalignment within 0.1 mm.…”

“…The power of both the pump and probe beams are locked using the methods in Ref. [28], and the frequency of the pump beam is locked to a stable single-mode He-Ne laser using a scanning Fabry-Perot cavity [34], which reduces the drift of the pump beam frequency to less than 10 MHz in a day.…”

“…On the other hand, the use of multipass cavity is an example of the passive method, which can increase the signal without changing the size or damaging the stability of the system. Due to the simplicity of design and use, Herriott cavities [23,24] are particularly suitable for the applications based on atomic cells, and have been widely applied in atomic magnetometry [25][26][27][28][29][30].…”

Search for axion-like dark matter with spin-based amplifiers

“…A further improvement of the experimental sensitivity to axion-like dark matter is anticipated. Scaling the volume of the vapor cell up to 100 cm 3 could improve the 87 Rb magnetometer sensitivity by a factor of about 10; further, it is possible to achieve better sensor performance using multipass vapor cells 53 . For an optimized search, it is necessary to optimize the amplification performance of spinbased amplifiers for ALP signals.…”