Correlation plenoptic imaging between arbitrary planes

Abstract

We propose a novel method to perform plenoptic imaging at the diffraction limit by measuring second-order correlations of light between two reference planes, arbitrarily chosen, within the tridimensional scene of interest. We show that for both chaotic light and entangledphoton illumination, the protocol enables to change the focused planes, in post-processing, and to achieve an unprecedented combination of image resolution and depth of field. In particular, the depth of field results larger by a factor 3 with respect to previous correlation plenoptic imaging protocols, and by an order of magnitude with respect to standard imaging, while the resolution is kept at the diffraction limit. The results lead the way towards the development of compact designs for correlation plenoptic imaging devices based on chaotic light, as well as high-SNR plenoptic imaging devices based on entangled photon illumination, thus contributing to make correlation plenoptic imaging effectively competitive with commercial plenoptic devices.1This is not the case in so called Plenoptic 2.0, where the microlenses create redundant images of the scene of arXiv:2007.12033v2 [physics.optics] 4 Aug 2020 interest [25] and propagation direction is obtained by a sort of triangulation, with the effect of improving the depth of field while further sacrificing the image resolution

Effect of Finite-Sized Optical Components and Pixels on Light-Field Imaging through Correlated Light

“…CPI is based on the simultaneous measurement and subsequent correlation of the light intensity distributions and , where and are two-dimensional (transverse) space coordinates defined on the photosensitive planes of two detectors and , respectively. The correlation function is evaluated from the measured intensity distributions as: where the angular brackets denote the statistical ensemble average [ 22 ] and the coefficient equals either 1, for thermal illumination, or 0, if the source is an emitter of entangled photon pairs [ 21 , 23 ]. Experimentally, an ergodic hypothesis is made on the statistical properties of the source, so as to replace the quantum state average with an operationally well-defined time average.…”

Towards Quantum 3D Imaging Devices

“…where M and M L are the magnifications of the images of the reference object plane and of the focusing element, respectively, while the power n is equal to 1 or 2, according to whether the object lies in only one [16,33,35] or both [36,37] optical paths. Experimental CPI based on pseudo-thermal light is shown in Figure 2c, where both the acquired out-of-focus image and the corresponding refocused image are shown [16].…”

“…The design of both quantum plenoptic devices are currently undergoing optimization by implementing a novel protocol that enables further mitigating the resolution vs. DOF compromise with respect to the one shown in Figure 2a: this protocol is based on the observation that, for any given resolution, the DOF can be maximized by correlating the standard images of two arbitrary planes, chosen in the surrounding of the object of interest, instead of imaging the focusing element [36]. Moreover, we are investigating the possibility to merge quantum plenoptic imaging with the measurement protocols developed in the context of differential ghost imaging [42].…”

Towards quantum 3D imaging devices: the Qu3D project

“…where M and M L are the magnifications of the images of the reference object plane and of the focusing element, respectively, while the power n is equal to 1 or 2, according to whether the object lies in only one [6,23,25] or both [26,27] optical paths.…”

“…The design of both quantum plenoptic devices are currently undergoing optimization by implementing a novel protocol that enables to further mitigate the resolution vs DOF compromise with respect to the one shown in Fig. 2a: this protocol is based on the observation that, for any given resolution, the DOF can be maximized by correlating the standard images of two arbitrary planes, chosen in the surrounding of the object of interest, instead of imaging the focusing element [26]. Moreover, we are investigating the possibility to merge quantum plenoptic imaging with the measurement protocols developed in the context of differential ghost imaging [32].…”