A three-axis atomic magnetometer for temperature-dependence measurements of fields in a magnetically shielded environment

High performance spin-exchange-relaxation-free (SERF) gyroscopes require stable and homogeneous magnetic fields. These fields are usually sensitive to temperature. In this paper, a three-axis atomic magnetometer to measure the temperature dependence of fields inside the magnetic shields for a SERF gyroscope prototype is constructed and tested. Based on a three-beam configuration, three-axis vector capability is obtained by a cross-modulation scheme of the magnetic field components along orthogonal axes and subsequent demodulation of the relevant probe signals. The relative temperature dependence of magnetic fields inside the prototype shields is measured to be 0.03-0.12 K^-1. The results are useful for estimating the necessary precision of temperature control in both a SERF gyroscope and its fundamental physics applications.