We present a single-shot quantum ghost polarimetry technique for quantitative birefringence imaging by replacing multi-orientation polarization sampling with a parallel four-analyzer readout. A single gated exposure yields a 2×2 mosaic of polarization-resolved ghost images whose relative intensities furnish the observables for per-pixel retardance and fast-axis retrieval. Idler photons of polarization-entangled biphotons probe a birefringent pattern and signal photons are routed to four analyzer channels and imaged by an intensified sCMOS as a simultaneous 2×2 mosaic. Relative intensities across the mosaic yield per-pixel retardance and fast-axis orientation. The multiplexed, correlation-based readout supports real-time, low-photon flux polarimetric microscopy and metrology of birefringence.
We present a single-shot quantum ghost polarimetry technique for quantitative birefringence imaging by replacing multi-orientation polarization sampling with a parallel four-analyzer readout. A single gated exposure yields a 2×2 mosaic of polarization-resolved ghost images whose relative intensities furnish the observables for per-pixel retardance and fast-axis retrieval. Idler photons of polarization-entangled biphotons probe a birefringent pattern and signal photons are routed to four analyzer channels and imaged by an intensified sCMOS as a simultaneous 2×2 mosaic. Relative intensities across the mosaic yield per-pixel retardance and fast-axis orientation. The multiplexed, correlation-based readout supports real-time, low-photon flux polarimetric microscopy and metrology of birefringence.
Polarimetric imaging, a technique that captures the invisible polarization-related properties of given materials, has broad applications from fundamental physics to advanced fields such as target recognition, stress detection, biomedical diagnosis and remote sensing. The introduction of quantum sources into classical imaging systems has demonstrated distinct advantages, yet few studies have explored their combination with polarimetric imaging. In this study, we present a quantum polarimetric imaging system that integrates polarization-entangled photon pairs into a polarizer-sample-compensator-analyzer (PSRA)-type polarimeter. Our system visualizes the birefringence properties of a periodical-distributed anisotropic material under decreasing illumination levels and diverse disturbing light sources. Compared to the classical system, the quantum approach reveals the superior sensitivity and robustness in low-light conditions, particularly useful in biomedical studies where the low illumination and non-destructive detection are urgently needed. The study also highlights the nonlocality of entangled photons in birefringence measurement, indicating the potential of quantum polarimetric system in the remote sensing domain.
Polarimetric imaging, a technique that captures the invisible polarization-related properties of given materials, has broad applications from fundamental physics to advanced fields such as target recognition, stress detection, biomedical diagnosis and remote sensing. The introduction of quantum sources into classical imaging systems has demonstrated distinct advantages, yet few studies have explored their combination with polarimetric imaging. In this study, we present a quantum polarimetric imaging system that integrates polarization-entangled photon pairs into a polarizer-sample-compensator-analyzer-typed polarimeter. Our system visualizes the birefringence properties of a periodical-distributed anisotropic material under decreasing illumination levels and diverse disturbing light sources. Compared to the classical system, the quantum approach reveals the superior sensitivity and robustness in low-light conditions, particularly useful in biomedical studies where the low illumination and non-destructive detection are urgently needed. The study also highlights the nonlocality of entangled photons in birefringence measurement, indicating the potential of quantum polarimetric system in the remote sensing domain.
Polarization entanglement of single photons is a key element to enable quantum 2.0 applications, such as quantum computing, quantum networks, and quantum sensing. Verification and fidelity assessment of the entanglement state are typically performed by sequential coincidence measurements with single-pixel photon detectors. Quantum imaging techniques that use single-photon imaging cameras for visualizing an entangled biphoton state and calculating Bell's inequality have been reported. Their performances are limited for practical use due to low photon flux and low speed. Here, we introduce a new approach to image polarization-entangled biphoton states using radial polarizations, which enables rapid high-performance entanglement measurement. An intensified single-photon counting camera (SPCC) captures a single image with multiple polarizations imposed by a radial wave plate, which converts a linear polarization of single photons to radial polarizations. The coincidence photon image is rapidly taken with the SPCC in the integrate-on-chip mode, which is triggered by the idler photons set at a specific polarization angle. Bell's inequality is calculated directly from four coincidence images that show polarization correlation. Our technique not only visualizes the entangled polarization state but also enables fast full Bell-type evaluation of photonic polarization entanglement. We envision that our approach may be instrumental for developing advanced polarization-entangled photon sources and polarization-entangled quantum systems, which in turn would advance fundamental research involving dynamic photon-matter interactions.
Correlated-photon imaging, popularly known as ghost imaging, is a technique whereby an image is formed from light that has never interacted with the object. In ghost imaging experiments two correlated light fields are produced. One of these fields illuminates the object, and the other field is measured by a spatially resolving detector. In the quantum regime, these correlated light fields are produced by entangled photons created by spontaneous parametric down-conversion. To date, all correlated-photon ghost-imaging experiments have scanned a single-pixel detector through the field of view to obtain the spatial information. However, scanning leads to a poor sampling efficiency, which scales inversely with the number of pixels, N, in the image. In this work we overcome this limitation by using a time-gated camera to record the single-photon events across the full scene. We obtain high-contrast images, 90%, in either the image plane or the far-field of the photon pair source, taking advantage of the EPR-like correlations in position and momentum of the photon pairs. Our images contain a large number of modes, >500, creating opportunities in low-light-level imaging and in quantum information processing.
Abstract Quantum‐correlation‐based ghost imaging, also termed quantum ghost imaging, has found applications as diverse as the fundamental tests of quantum mechanics and low‐light‐level imaging. In any previous schemes, however, only biphoton spatial entanglement is utilized, whereas other degrees of freedom of the photons have not yet been explored. Here we break this barrier to present a multichannel parallel ghost imaging system, by exploiting hyperentanglement where photon pairs are simultaneously entangled in polarization, color, and spatial mode. In the experiment, polarization and color entanglements provide 2× 2 independent channels via simultaneous polarization and color multiplexing, while an optical isolator with a delay line is constructed to ensure that spatial entanglement conveys the ghost image in parallel. The method can offer a pathway for high‐capacity quantum image processing and transmission in future quantum network.
Correlated photon imaging, popularly known as ghost imaging, is a technique whereby an image is formed from light that has never interacted with the object. In ghost imaging experiments, two correlated light fields are produced. One of these fields illuminates the object, and the other field is measured by a spatially resolving detector. In the quantum regime, these correlated light fields are produced by entangled photons created by spontaneous parametric down-conversion. To date, all correlated photon ghost imaging experiments have scanned a single-pixel detector through the field of view to obtain spatial information. However, scanning leads to poor sampling efficiency, which scales inversely with the number of pixels, N , in the image. In this work, we overcome this limitation by using a time-gated camera to record the single-photon events across the full scene. We obtain high-contrast images, 90%, in either the image plane or the far field of the photon pair source, taking advantage of the Einstein–Podolsky–Rosen-like correlations in position and momentum of the photon pairs. Our images contain a large number of modes, >500, creating opportunities in low-light-level imaging and in quantum information processing.