Detection of Zero-field resonance

Zero-field resonance (ZFR) is a phenomenon in which an atomic medium is largely transparent to laser light at zero or near-zero magnetic field and is largely opaque to laser light at other values of the magnetic field. The transparency range might be, for example, -100 nT to +100nT in any of the three vector components of the magnetic field. For comparison, the field of the earth is about 50 µT or 50,000 times larger thatn the transparency range.The present invention relates to a method and an apparatus for detecting zero-field resonance and, in particular, magnetometers employing the zero-field resonance effect.