Quantum correlation light-field microscope with extreme depth of field

Light-field microscopy (LFM) is a 3D microscopy technique whereby volumetric information of a sample is gained by simultaneously capturing both the position and momentum (angular) information of light illuminating a scene. Conventional LFM designs generally require a trade-off between position and momentum resolution, requiring one to sacrifice resolving power for increased depth of field (DOF) or vice versa. In this work, we demonstrate a LFM design that does not require this trade-off by utilizing the inherent correlations between spatial-temporal entangled photon pairs. Here, one photon from the pair is used to illuminate a sample from which the position information of the photon is captured directly by a camera. By virtue of the strong momentum anti-correlation between the two photons, the momentum information of the illumination photon can then be inferred by measuring the angle of its entangled partner on a different camera. By using a combination of ray-tracing and a Gerchberg-Saxton type algorithm for the light field reconstruction, we demonstrate that a resolving power of 5 $\mu$m can be maintained with a DOF of $\sim500$ $\mu$m, approximately 3 times of the latest LFM designs or $>100$ time that of a conventional microscope. In the extreme, at a resolving power of 100 $\mu$m, it is possible to achieve near infinite DOF.