Abstract: The disclosure describes optically pumped magnetometers and systems incorporating, and methods of operating, the same. An optically pumped magnetometer according to one embodiment of the present technology includes a vapor cell configured to contain an atomic absorber such as rubidium-87, and at least one light source in optical communication with the vapor cell. The optically pumped magnetometer includes components positioned and configured to provide a bias field, and induce a zeroing field, within the vapor cell. Among other useful and advantageous ends, embodiments of the present technology provide for increasing the degree of atomic polarization in optically pumped magnetometers based on zeroing the bias magnetic field during the optical pumping process.

Abstract: Various embodiments of the present technology use low-frequency magnetic signals for communication and location applications. Compared to the case of traditionally used radio-frequency electromagnetic signals, their advantage in the presence of strong signal attenuation is in the extended spatial range. Some embodiments use an optically pumped atomic magnetometer operated as a sensor to achieve high detection sensitivity. The spatial range can be extended to hundreds of meters when noise is suppressed by the use of the available sensor sensitivity. In some embodiments, a one-channel spread-spectrum signal processing technique can be used to eliminate the systematic fluctuations coming from power grid (or another source) harmonics and reduce the ambient noise by averaging uncorrelated fluctuations from the environment.

Abstract: The disclosure describes optically pumped magnetometers and systems incorporating, and methods of operating, the same. An optically pumped magnetometer according to one embodiment of the present technology includes a vapor cell configured to contain an atomic absorber such as rubidium—87, and at least one light source in optical communication with the vapor cell. The optically pumped magnetometer includes components positioned and configured to provide a bias field, and induce a zeroing field, within the vapor cell. Among other useful and advantageous ends, embodiments of the present technology provide for increasing the degree of atomic polarization in optically pumped magnetometers based on zeroing the bias magnetic field during the optical pumping process.

Abstract: A probe beam is passed through a first optically pumped magnetometer vapor cell portion that has a first magnetic bias field orientation relative to a pump beam. The probe beam is also passed through a second optically pumped magnetometer vapor cell portion that has a second magnetic bias field orientation relative to the pump beam with the same properties as in the first portion, where the first magnetic bias field orientation is opposite to that of the second magnetic bias field orientation. This configuration reduces or eliminates linearly polarized magnetic signals (e.g., noise) from the output probe beam and passes circularly polarized magnetic signals. Thus, the intensity of the probe beam after passing through the first and second optically pumped magnetometer vapor cell portions is measured to obtain a noise suppressed signal.

Abstract: In some embodiments, two light beams having different frequencies can be counter-propagated through an atomic absorber having an atomic transition frequency approximately equal to the sum of the frequencies of the two beams. When the beams are appropriately tuned, the atomic absorber absorbs significant amount of light of at least the lower power beam. The amount of light remaining after the absorber is an indication of how well the frequencies are tuned to the absorber. At least one of the beam frequencies has an FM modulation applied prior to the absorber. This means the phase of the remaining light compared to the FM modulation, along with the intensity of the remaining light, can be used to provide a first feedback signal to adjust the frequencies of the beams to match the absorber frequency. Finally, both beams have amplitude modulation applied before the absorber.

Abstract: In some embodiments, two light beams having different frequencies can be counter-propagated through an atomic absorber having an atomic transition frequency approximately equal to the sum of the frequencies of the two beams. When the beams are appropriately tuned, the atomic absorber absorbs significant amount of light of at least the lower power beam. The amount of light remaining after the absorber is an indication of how well the frequencies are tuned to the absorber. At least one of the beam frequencies has an FM modulation applied prior to the absorber. This means the phase of the remaining light compared to the FM modulation, along with the intensity of the remaining light, can be used to provide a first feedback signal to adjust the frequencies of the beams to match the absorber frequency. Finally, both beams have amplitude modulation applied before the absorber.

Abstract: Various embodiments of the present technology use low-frequency magnetic signals for communication and location applications. Compared to the case of traditionally used radio-frequency electromagnetic signals, their advantage in the presence of strong signal attenuation is in the extended spatial range. Some embodiments use an optically pumped atomic magnetometer operated as a sensor to achieve high detection sensitivity. The spatial range can be extended to hundreds of meters when noise is suppressed by the use of the available sensor sensitivity. In some embodiments, a one-channel spread-spectrum signal processing technique can be used to eliminate the systematic fluctuations coming from power grid (or another source) harmonics and reduce the ambient noise by averaging uncorrelated fluctuations from the environment.

Abstract: A magnetometer and method of use is presently disclosed. The magnetometer has at least one sensor void of extraneous metallic components, electrical contacts and electrically conducting pathways. The sensor contains an active material vapor, such as an alkali vapor, that alters at least one measurable parameter of light passing therethrough, when in a magnetic field. The sensor may have an absorptive material configured to absorb laser light and thereby activate or heat the active material vapor.

Abstract: A magnetometer and method of use is presently disclosed. The magnetometer has at least one sensor void of extraneous metallic components, electrical contacts and electrically conducting pathways. The sensor contains an active material vapor, such as an alkali vapor, that alters at least one measurable parameter of light passing therethrough, when in a magnetic field. The sensor may have an absorptive material configured to absorb laser light and thereby activate or heat the active material vapor.