Two-photon Hong-Ou-Mandel-based sensor with N -fold maximal precision

The two-photon Hong-Ou-Mandel (HOM) interferometry sensor has attracted much attention in recent decades due to its numerous advantages, such as robustness against background noise, group velocity dispersion, and phase perturbations. However, the maximum measurement precision of a single measurement is limited by the Heisenberg uncertainty at the two-photon level, which constrains the development of a HOM-based sensor. In this paper, we combine the multipass approach of a sequential scheme for quantum metrology with the traditional HOM-based sensor, and provide a general theoretical scheme of a multipass HOM-based sensor. For N passes of the probe through the sample, our proposed scheme offers an N-fold improvement in the precision of parameter estimation compared to a traditional HOM-based sensor under the same number of measurement repetitions. Furthermore, we present the simulation results of decoherence models for the multipass HOM-based sensor by introducing phase diffusion and photon loss, which are significantly enhanced due to the multipass approach. Last, we present the predictions of achievable precision for the multipass HOM-based sensor, considering measurement repetitions of the order of 104 in a sample with a thickness of 100μm.