Comparison and limitations of quantum lidar in the single-photon regime
Anthony Drouin, Jean-Philippe Bourgoin, Sara Hosseini +3 more
Quantum lidar leverages the quantum properties of light to gain advantages over classical lidar, such as enhancing range accuracy and reducing the emitted optical power needed to detect a target. The low optical power makes quantum lidar especially attractive for minimizing the probability of being detected by an adversary. Various quantum sources have been considered for quantum lidar; however, a practical comparison between such widely different systems is challenging. Here, we develop a theoretical model tailored to quantum lidar for stealth ranging and imaging, and compare the performance of such systems using an attenuated pulsed laser, a quantum dot single-photon source, and a spontaneous parametric down-conversion correlated photon pair source. To ensure a fair comparison, all sources employ time correlations for detection and are equalized in terms of optical power and detectability by an adversary. Furthermore, we demonstrate the limitation of the signal-to-noise ratio (SNR) as a sole metric, as it ignores the acquisition time required to confidently identify a target. To address the limitation of SNR, we supplement this metric with receiver operating characteristic (ROC) curves. With the inclusion of ROC curves, we find that the pulsed laser and the quantum dot single-photon source outperform the correlated photon pair source when an adversary possesses a non-photon-number-resolving detector. In contrast, when facing a photon-number-resolving detector, the quantum dot single-photon source remains optimal while the correlated photon pair source outperforms the pulsed laser. Our findings demonstrate that the use of a correlated photon pair source for quantum lidar does not always outperform alternative sources with equal SNR and optical power. Finally, using ROC curves, we establish the practical range limitations of quantum lidar.
Optica Quantum•Sep 17, 2026•0 citations