Ultracold-atom gyroscope based on a spiral Bessel beam

The Sagnac interferometer for angular-velocity metrology is a hot field in precision measurement. How to increase the area of its interference loop is one of its important concerns. In this paper, we design an ultracold-atom gyroscope by using a far-off-resonance, steerable Bessel optical dipole trap. The standing-wave Bragg beams split, reflect, and recombine the Bose–Einstein condensate packets. Concurrently, the Bessel guide drives a helical, quasi-free trajectory. The key advance of our proposal is that optical guiding enables stable multi-orbit operation in a programmable helical waveguide, providing a scalable route to enhance the effective Sagnac area within a compact footprint. As a representative operating point, we show that N =8 turns with R =0.6 mm yield an effective enclosed area A eff ≈72.4 mm 2 and a correspondingly large Sagnac sensitivity. It is a strong candidate for next-generation atom gyroscopes in rotation sensing.