Quantum enhancement detection techniques for FMCW LiDAR

Interferometric LiDAR is a device that is used to achieve distance, velocity and phase estimation with high precision and resolution through the use of frequency-modulated continuous wave (FMCW). In this instance, we study quantum enhancement detection techniques for a Mach-Zender interferometer with a FMCW coherent state input. Various quantum detection methods-including NOON state detection, coincidence detection, and sum of parity detection-are applied to the FMCW coherent state and compared against the classical heterodyne detection technique. The findings reveal the potential to trade maximum detectable distance for resolution enhancement. Furthermore, classical Fisher information is utilized to validate and quantify the precision limits of each detection technique. In scenarios characterized by high losses, it is observed that the precision limits of coincidence detection, sum of parity detection, and classical detection techniques are comparable. Therefore, this study offers practical guidance for designing quantum-enhanced receivers for FMCW LiDAR systems.