A waveguide magneto-optic sensor provides a signal indicative of the value
and/or direction of a detected magnetic field by a spectral shift of the
characteristic resonant spectral feature of the sensor is disclosed. The
sensor does not suffer from vibrations, fiber bending or other light
intensity noise and provides an absolute self-referencing signal. The
sensor elements can easily be coupled to optical fibers and read with
scanning spectrometers or scanning lasers calibrated against
NIST-traceable gas absorption standards.