A parametrically modulated dual-axis atomic spin gyroscope.

We describe a dual-axis atomic spin gyroscope based on an alkali metal-noble gas comagnetometer. Alkali metal vapor is optically pumped, and then the noble gas is hyperpolarized along the <italic>z</italic> axis. When sensing a transverse rotation, the polarized noble gas will be induced to precess and produce an effective magnetic field in the <italic>x</italic> – <italic>y</italic> plane for alkali metals to precess under. Operating in the spin-exchange relaxation-free regime, alkali atoms are modulated by the <italic>z</italic> axis magnetic field and serve as an integrated <italic>in-situ</italic> dual-axis magnetometer to detect the gyroscopic precession in the <italic>x</italic> and <italic>y</italic> axes simultaneously, using a single probe beam. By using the parametric modulation technique, the low frequency drift is effectively suppressed and a bias instability of less than 0.05 deg/h has been achieved in our dual-axis atomic spin gyroscope. [ABSTRACT FROM AUTHOR]