Quantum-Enhanced Sub-Rayleigh Imaging with the BLESS Method

Conventional far-field imaging systems are fundamentally limited in resolution by the Rayleigh criterion, which arises from diffraction and is determined by the wavelength of light and the numerical aperture of the optical system. In fluorescence microscopy, several super-resolution techniques—such as STED [1] and PALM/STORM [2,3]—have been developed to overcome this limit via controlled activation and deactivation of fluorescent emitters. These methods, however, often come with trade-offs such as elevated phototoxicity, slow acquisition speeds, and limited compatibility with certain dyes.
An alternative approach to surpassing the diffraction limit involves statistical localization of emitters using engineered point spread functions (PSFs) [4]. While effective for equally bright sources, these techniques encounter challenges when dealing with unbalanced emitters [5] or with the localization of multiple sources [6].
In this talk, we present Beam Modulation and Examination of Shot Statistics (BLESS) [7], a recently proposed quantum-inspired method that enables precise distance estimation between two unbalanced single-photon sources at sub-Rayleigh separations—achieving resolution an order of magnitude beyond the classical limit. We will discuss its experimental implementation, applicability to diverse photon statistics, and its extension to multi-emitter localization problems.