Skip to main content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.


The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Self-Oscillating Rubidium Magnetometer using Nonlinear Magneto-Optical Rotation



P Schwindt, Leo W. Hollberg, John E. Kitching


The detection of nonlinear magneto-optical rotation (NMOR) of polarized light through alkali atomic vapor is a highly sensitive technique for measuring magnetic fields. We demonstrate that when using frequency modulated light to excite the NMOR resonance, it is possible to cause the system to self oscillate. The NMOR signal is not a simple replication of the sine wave modulation of the light, but rather contains many higher harmonics of the modulation frequency, and we implement two ways of processing the signal to recover the fundamental modulation frequency in the feedback loop and induce self oscillation. Self oscillation greatly simplifies and reduces the power consumption of the electronics required to operate a magnetometer making the NMOR technique more attractive for commercialized magnetic sensors.
Review of Scientific Instruments


atomic spectroscopy, magneto-optical rotation, magnetometry
Created December 14, 2005, Updated February 17, 2017