Stable and High-Precision 3D Positioning via Tunable Composite-Dimensional Hong-Ou-Mandel Interference

We propose a stable and high-precision three-dimensional (3D) quantum positioning scheme based on Hong-Ou-Mandel interference. While previous studies have explored HOM interference in quantum metrology, they were mostly limited to one-dimensional scenarios, whereas real-world applications require full 3D spatial resolution. Our approach not only generalizes HOM positioning to 3D-achieving ultimate sensitivity as defined by the quantum Cramer-Rao bound-but also stabilizes estimation accuracy through simple polarization tuning, ensuring that the Fisher information remains independent of the estimated parameters. Theoretical analysis and simulations demonstrate that our method achieves ultra-precise and reliable 3D positioning, even with a limited number of detected photons.