Noise‐Resistant Correlated Biphoton Imaging Based on the Superbunching Emission From Single Colloidal Quantum Dots

Abstract

ABSTRACT Quantum‐correlated techniques enable high‐contrast and super‐resolution imaging through the feature of correlated photons. The superbunching effect with a second‐order correlation larger than 2, i.e., g (2) (0) > 2, demonstrates the existence of strong correlations between photons, which can enable stray light resistance and achieve high‐contrast imaging. Here, we present a scheme for quantum correlated imaging using single colloidal quantum dots (CQDs) with strong superbunching emission. The optimized CdSe/ZnS CQDs with g (2) (0) up to 69 and 20 under continuous‐wave and pulsed laser excitation have been prepared. We achieved noise‐resistant correlated biphoton imaging (CPI) based on single CQDs with noise intensity 104 times stronger than their photoluminescence. By modulating photoluminescence intensity, the Fourier‐domain CPI was determined with reasonably good contrast, despite noise 75 600 times stronger than biphoton counts. Our proposal may enable laboratory‐based quantum imaging to be applied to real‐world applications with the desired suppression of intense stray light.