Spin Polarized Atomic Sensors – Developing Gyroscopes and Magnetometers

Northrop Grumman has been developing spin polarized atomic sensors since 1967. The work started with the development of a Nuclear Magnetic Resonance Gyroscope (NMRG) using then new techniques of spin exchange optical pumping and co-magnetometry. Offshoot technologies soon followed including magnetometers and atomic clocks leveraging the common supporting technologies. This presentation will describe the development history, underlying physics of operation, common supporting technologies, and current status of the NMRG and related offshoot technologies.

Optically Pumped Magnetometers: From Laboratory to Real-World

In my talk, I will give an overview of the work at QuSpin on developing commercial grade optically pumped magnetometers (OPM). Specifically, I will discuss the current status of our zero-field and scalar OPM technology, and our view on the technical potential of this technology in the next five years. I will also share our experience in taking this technology from laboratory to commercial domain.

Microfabricated Optically-Pumped Magnetometers for Non-Invasive Brain Imaging

We present our ongoing effort in developing imaging systems with microfabricated optically-pumped magnetometers (µOPMs). By use of microfabrication technologies and simplification of optical setups, we aim to develop manufacturable sensors of small size and low power. Our zero-field µOPMs require a shielded environment but reach high sensitivities of less than 10 fT/Hz^1/2. Target applications lie in the field of non-magnetic brain imaging, specifically magnetoencephalography (MEG). The attraction of using these sensors for non-invasive brain imaging comes from the possibility of placing them directly on the scalp of the patient, very close to the brain sources. We have built several multi-channel test systems to validate the prediction of very high signal-to-noise ratios in standard MEG paradigms.

Finite-field high-sensitivity sensors

Modern alkali metal sensors achieve both high performance and smaller size thanks to breakthroughs in suppressing the effects of spin-exchange collisions among atoms, both at zero field and now at finite field. While zero field SERF magnetometers with less than 10 fT.Hz^-1/2 sensitivity are now an established technique, achieving the same performance at finite field is an exciting new development, potentially obviating the need for costly magnetic shielding. I review the history of this field and discuss commercial development of sensors at Twinleaf.

Miniature Scalar Atomic Magnetometers: Advances and Applications

Scalar magnetometers are used to make very precise measurements of small deviations in the Earth’s field to detect a wide variety of objects ranging from pipes and unexploded ordnance (UXO) to submarines. Atomic magnetometers are typically used as the sensor of choice in measuring the magnitude of the Earth’s magnetic field through the Larmor precession of atomic spins. Over the past five decades, scalar atomic magnetometry technology has relied on radio frequency (RF) magnetic fields to drive the Larmor precession and RF discharge lamps as the light source to detect the precession. Within the past ten years, Vertical Cavity Surface Emitting Laser (VCSEL) technology, developed for chip scale atomic clocks, has enabled significant miniaturization of the atomic magnetometers with commensurate decrease in power consumption. The miniature magnetometers now allow integration of these sensors in numerous applications where earlier, the size and weight of the lamp-based sensors precluded their use. In this talk, I present an overview of scalar atomic magnetometer development at Geometrics. I further present the application of these sensors in geophysical measurements and beyond, touching upon magnetocardiography, non-destructive testing of conductive bulk materials, and infrastructure monitoring. The convergence of a number of technologies including the development of autonomous platforms, heuristic analyses of large data sets, and ubiquitous computing opens up substantially new application areas for the miniature atomic magnetometers with seemingly unending possibilities.