Quantum FOGs: Researchers Achieve Sub-Shot-Noise Precision in Rotation Detection
Researchers have made significant strides in improving the precision of fiber optic gyroscopes (FOGs) using quantum enhancements. These advancements promise to revolutionize the measurement of rotation, enabling detection of subtle angular movements.
Stefan Evans and Joanna Ptasinski have been investigating key sources of uncertainty in quantum-enhanced FOGs. One such source is uncorrelated photon saturation. To overcome this, they propose using entangled photonic N00N states, which offer substantial advantages over classical optical instruments.
Maintaining the coherence and entanglement of these N00N states is crucial for optimal performance. However, phase uncertainty in enhanced FOGs fluctuates, creating unstable points within the measurement. To address this, researchers are exploring quantum noise mitigation techniques, which can potentially reduce phase uncertainty by over an order of magnitude. This would enable the detection of even smaller angular rotations.
Several noise sources affect FOG accuracy, including chromatic and polarization mode dispersion, pump laser instabilities, and single photon saturation. However, stable domains centered on optimal bias points exist where instability remains below the level of shot noise. Careful selection of bias phase and fibre length can enhance sensitivity and mitigate noise in quantum FOGs.
The optimization of phase amplification angles in quantum FOGs is a promising avenue for achieving sub-shot-noise precision. With continued research and development, these advancements could lead to significant improvements in navigation, guidance, and sensing technologies.
