Sagnac atom interferometer gyroscope with large enclosed area and multiple orbits

Sagnac atom interferometers are a promising technique for high-performance rotation sensing, with potential applications for inertial navigation. The use of trapped atoms for the interferometer avoids the need for long free-fall distances that would be incompatible with a navigation apparatus. We have previously demonstrated a dual Sagnac interferometer using Bose-condensed atoms in a time-orbiting potential trap. We report here on improvements to this approach, including a 3-fold increase in the orbit radius and the use of multiple orbits. These improvements lead to an enclosed area of 6.6 mm², which corresponds to a rotation sensitivity of 6×10^-7 rad/s at shot-noise-limited detection. While shot-noise-limited performance has not yet be achieved, the interferometer operation is sufficiently stable to permit useful averaging times longer than 10⁴ s. We also discuss a new, more compact, version of the apparatus that is based on an atom chip and which will be suitable for environmental testing.