Fig. 1: Logical diagram of the experimental setup with illustrative temporal distributions.
From: Quantum and non-local effects offer over 40 dB noise resilience advantage towards quantum lidar
a Temporal distribution of probe and reference photons directly after spontaneous parametric down conversion (SPDC). b Temporal distribution of the probe and reference photons after free-space/target loss. c Temporal distribution of the noise, probe, and reference photons after coupling of environmental noise. d Temporal distribution of the noise, probe, and reference photons after positive and negative group-velocity dispersion (GVD) fibers. f Theoretical coincidence probability histograms for true coincidences (e) and false coincidence (f) in both the non-dispersed (blue) and dispersed (red) regimes. The model uses joint-spectral amplitude (JSA) bandwidths of 100 fs and 17.7 ps full-width at half maximum (FWHM) estimated from the Ti:Sapphire laser and second harmonic generation (SHG) spectrum of the PPLN waveguide used for probe–reference pair generation, the dispersion and length of the fibers (18ps/nm km, 5 km), and detector time uncertainty (83.3 ps) FWHM.
