Quantum imaging has non-negligible advantages in terms of sensitivity, signal-to-noise ratio, and novel imaging schemes. Based on metasurfaces, the information density and stability of the quantum imaging system can be further improved. Here we experimentally demonstrate that two patterns, simultaneously and independently superimposed on a high-efficiency dielectric metasurface, can be remotely switched via polarization-entangled photon pairs. Furthermore, using the time-correlated property of entangled photon pairs, the information carried by quantum light can be remarkably discriminated from background noise. This work confirms that the phase manipulation of quantum light with metasurfaces has a huge potential in the field of quantum imaging, quantum state tomography, and also promises real-world quantum metasurface devices.
Quantum imaging has non-negligible advantages in terms of sensitivity, signal-to-noise ratio, and novel imaging schemes. Based on metasurfaces, the information density and stability of the quantum imaging system can be further improved. Here we experimentally demonstrate that two patterns, simultaneously and independently superimposed on a high-efficiency dielectric metasurface, can be remotely switched via polarization-entangled photon pairs. Furthermore, using the time-correlated property of entangled photon pairs, the information carried by quantum light can be remarkably discriminated from background noise. This work confirms that the phase manipulation of quantum light with metasurfaces has a huge potential in the field of quantum imaging, quantum state tomography, and also promises real-world quantum metasurface devices.
Quantum entanglement is a key resource that can be exploited for a range of applications such as quantum teleportation, quantum computation, and quantum cryptography. However, efforts to exploit entanglement in imaging systems have so far led to solutions such as ghost imaging, that have since found classical implementations. Here, we demonstrate an optical imaging protocol that relies uniquely on entanglement: Two polarizing patterns imprinted and superimposed on a metasurface are separately imaged only when using entangled photons. Unentangled light is not able to distinguish between the two patterns. Entangled single-photon imaging of functional metasurfaces promises advances towards the use of nanostructured subwavelength thin devices in quantum information protocols and a route to efficient quantum state tomography.
Metasurfaces consisting of engineered dielectric or metallic structures provide unique solutions to realize exotic phenomena including negative refraction, achromatic focusing, electromagnetic cloaking, and so on. The intersection of metasurface and quantum optics may lead to new opportunities but is much less explored. Here, we propose and experimentally demonstrate that a polarization-entangled photon source can be used to switch ON or OFF the optical edge detection mode in an imaging system based on a high-efficiency dielectric metasurface. This experiment enriches both fields of metasurface and quantum optics, representing a promising direction toward quantum edge detection and image processing with remarkable signal-to-noise ratio.
Traditional quantum imaging is featured by remarkable sensitivity and signal-to-noise ratio, but limited by bulkiness and static function (either phase contrast imaging or edge detection). Our report synergizes a polarization-entangled source with a metasurface consisting of various sophisticatedly engineered spatial frequency segments. By tuning polarization, we demonstrate multiple "on"-state quantum imaging modes, enabling flexible switching between phase contrast, edge, and arbitrary superimposed imaging mode. Furthermore, the "off"-state, which characterizes the background noise, enables self-calibration of the system by subtracting this noise in "on"-state modes, resulting in self-enhanced edge detection. Our approach performs phase contrast imaging with a phase difference of π/4 present in the target object, and edge imaging capable of detecting tiny (radius about 2 μm) defects, maintaining high image contrast (phase contrast of 0.726, and enhanced edge contrast of 0.902). Our results provide insights into constructive duet between quantum imaging and metaoptics.
Phase contrast microscopy is essential in optical imaging, but traditional systems are bulky and limited by single-phase modulation, hindering visualization of complex specimens.Metasurfaces, with their subwavelength structures, offer compact integration and versatile light field control.Quantum imaging further enhances performance by leveraging nonclassical photon correlations to suppress classical noise, improve contrast, and enable multifunctional processing.Here, we report, a dual-mode bright-dark phase contrast imaging scheme enabled by quantum metasurface synergy.By combining polarization entanglement from quantum light sources with metasurface phase modulation, our method achieves highcontrast, adaptive bright-dark phase contrast imaging of transparent samples with arbitrary phase distributions under low-light conditions.Compared to classical weak light imaging, quantum illumination suppresses environmental noise at equivalent photon flux, improving the contrast from 0.22 to 0.81.Moreover, quantum polarization entanglement enables remote switching to ensure high-contrast imaging in at least one mode, supporting dynamic observation of biological cells with complex phase structures.This capability is especially valuable in scenarios where physical intervention is difficult, such as in miniaturized systems, in vivo platforms, or extreme environments.Overall, the proposed scheme offers an efficient noninvasive solution for biomedical imaging with strong potential in life science applications.
Metasurfaces can precisely manipulate the amplitude, phase, and polarization of incident light through subwavelength structures, greatly advancing the quantum meta-holographic imaging. However, the current methods of using quantum holography only control either the amplitude or the phase on the imaging plane, so the resulted scalar holography without the polarization distribution has limited imaging channels. Here, the vectorial meta-holography using entangled signal-idler photon pairs is experimentally demonstrated to realize remotely controlled multi-channel quantum imaging. By simultaneous control of the amplitude ratio between two cross-polarization holographic images and their phase difference on the image plane, the polarization distribution accordingly changes with the incident polarization state. The accurate correspondence ensures the correct reconstruction of 32 incident polarization states with an average fidelity up to 94.78%. This enables entangled idler photons to remotely control the holographic images reconstructed by the entangled signal photons, where the signal-to-noise ratio is as high as 10.78 dB, even for maximally mixed quantum states. This vectorial meta-holography using entangled states has a larger polarization state information capacity and will facilitate miniaturized quantum imaging and efficient quantum state tomography.
Quantum imaging using entangled photon pairs from spontaneous parametric down-conversion (SPDC) provides fundamental advantages over classical phase imaging in the study of transparent object, such as the operation at ultra-low photon flux and high signal-to-noise ratio [1], [2]. Metasurfaces supporting angle-dependent resonances have recently been employed to achieve phase imaging by extracting phase gradients of incident light [3]. These nanoscale metasurfaces indicate significant potential to replace bulky differential interference contrast microscopes, offering an opportunity for integration into ultra-compact biomedical devices. Together with recent development on metasurface-based quantum light source, this opens up the potential for developing a compact quantum phase imaging device, where metasurfaces serve both generation and detection functions.