Ivano Ruo-Berchera - INRIM

Advanced Quantum Optical Imaging and Sensing Surpassing Classical Limits 

Advancements in quantum optics enable imaging and sensing protocols that surpass classical constraints. This work presents three major achievements in quantum-enhanced metrology, demonstrating how spatial and temporal photon correlations achieve unprecedented performance in biological imaging and remote sensing.

First, we introduce a quantum phase imaging technique exploiting sub-shot-noise spatial correlations from Spontaneous Parametric Down-Conversion (SPDC). By integrating these correlations with non-interferometric methods, we overcame the trade-off between noise reduction and spatial resolution. This enabled the first demonstration of a quantum advantage in wide-field imaging of biological cells, providing high-contrast phase information below the shot-noise limit [1].

In super-resolution microscopy, we developed a non-invasive fluorescence microscopy technique based on pixel-level photon statistics [2]. Our method enhances classical frameworks like Super-resolution Optical Fluctuation Imaging (SOFI) and is fully compatible with Structured Illumination Microscopy (SIM). This synergy boosts resolution further, pushing sub-diffraction boundaries without increasing phototoxicity [2].

Finally, we address quantum advantages in Time-of-Flight (ToF) ranging. Using a multiple-hypothesis testing model, we verified superior precision in quantum-enhanced distance measurements [3]. Crucially, we explore covert sensing, showing that detecting a target while remaining undetected is uniquely possible through low-photon-number quantum correlations. This provides a novel justification for quantum LIDAR and secure, non-invasive detection [4].

These results represent a significant step toward integrating quantum states into next-generation optical instruments.

[1] A. Paniate, G.  Ortolano, S. Soman, et al.  Optica 13, 375-385 (2026)

[2] F. Picariello, E. Losero, S. Ditalia Tchernij, et al.  Optica 12, 490-497 (2025). 

[3] G. Ortolano, I. Ruo-Berchera, Phys. Rev. Research 7, L022059 (2025). 

[4] G. Ortolano, I. Ruo-Berchera, L. Banchi, Phys. Rev. Lett. 136, 060801 (2026)