Optically pumped helium magnetometers are important instruments whichhave many applications in military, mass spectroscopy and space applications. In thispaper, the working principles of helium magnetometers have been explained. There isalso an introduction of a new method for finding the resonant frequency, which hasadvantages to the typical method such as more sample r...

We report on extensive studies on the intrinsic sensitivity of a combined He/Cs magnetometer. The magnetometer relies on the detection of the free spin precession of nuclear spin polarized He by optically pumped cesium magnetometers. We characterize the relevant processes involved in the detection and quantify their impact on the total sensitivity of the magnetometer. An expression is derived t...

Quantum magnetometers based on optical pumping can achieve sensitivity as high as what SQUID-based devices can attain. In this paper, we discuss the principle of operation and the optimal design of an optically pumped quantum magnetometer. The ultimate intrinsic sensitivity is calculated showing that optimal performance of the magnetometer is attained with an optical pump power of 20 μW and an ...

We describe an optically pumped 87Rb magnetometer with 5 fT/Hz(1/2) sensitivity when operated in the spin-exchange relaxation free (SERF) regime. The magnetometer uses a microfabricated vapor cell consisting of a cavity etched in a 1 mm thick silicon wafer with anodically bonded Pyrex windows. The measurement volume of the magnetometer is 1 mm3, defined by the overlap region of a circularly pol...

We report on the design and performance of a highly sensitive combined He/Cs magnetometer for the absolute measurement of magnetic fields. The magnetometer relies on the magnetometric detection of the free spin precession of nuclear spin polarized He gas by optically pumped cesium magnetometers. We plan to deploy this type of combined magnetometer in an experiment searching for a permanent elec...

20 Optically pumped atomic magnetometers measure the Larmor frequency νL at which the bulk magnetization of a spin-polarized alkali metal vapour in a glass cell precesses around the field of interest B0. !e precession frequency is related to the modulus of the magnetic field by νL=(γ/2π)|B0|, where γ/2π≈3.5Hz/nT for 133Cs, so that the magnetic field measurement consists in a frequency measureme...

We present an experimental and theoretical study of a scalar atomic magnetometer using an oscillating field-driven Zeeman resonance in a high-density optically pumped potassium vapor. We describe an experimental implementation of an atomic gradiometer with a noise level below 10 fT Hz−1/2, fractional field sensitivity below 10−9 Hz−1/2, and an active measurement volume of about 1.5 cm3. We show...