Abstract Quantum imaging is an advanced method for microscopy or investigating the optical properties of materials or bio-medical inspections with high accuracy, low noise, and extremely low photo-damage. In previous work, we proposed a quantum imaging technique, in which variations in polarization angle due to reflection or transmission at the sample enhance image contrast in the second-order autocorrelation function at zero delay g 2(0). However, the image resolution observed was not satisfactory. In this report, to improve the image quality, the parameters such as coincidence window was optimized to distinguish photon statistics effectively due to change in polarization angle and the objective lens was utilized to focus the entangled photon beams. These modifications enabled optical imaging by accurately detecting slight polarization variations in different media. Although this method is effective for various samples, it has certain limitations for samples that exhibit polarization disturbances, such as those involving photon scattering. Nevertheless, the proposed approach demonstrates superior imaging performance under noisy conditions and low illumination, offering promising possibilities for high-quality quantum imaging applications.
Abstract Quantum imaging is an advanced method for microscopy or investigating the optical properties of materials or bio-medical inspections with high accuracy, low noise, and extremely low photo-damage. In previous work, we proposed a quantum imaging technique, in which variations in polarization angle due to reflection or transmission at the sample enhance image contrast in the second-order autocorrelation function at zero delay g 2(0). However, the image resolution observed was not satisfactory. In this report, to improve the image quality, the parameters such as coincidence window was optimized to distinguish photon statistics effectively due to change in polarization angle and the objective lens was utilized to focus the entangled photon beams. These modifications enabled optical imaging by accurately detecting slight polarization variations in different media. Although this method is effective for various samples, it has certain limitations for samples that exhibit polarization disturbances, such as those involving photon scattering. Nevertheless, the proposed approach demonstrates superior imaging performance under noisy conditions and low illumination, offering promising possibilities for high-quality quantum imaging applications.
Quantum imaging is an advanced method for microscopy or investigating the optical properties of materials or bio-medical inspections with high accuracy, low noise, and extremely low photo-damage. In previous work, we proposed a quantum imaging technique, in which variations in polarization angle due to reflection or transmission at the sample enhance image contrast in the second-order autocorrelation function at zero delay g2(0). However, the image resolution observed was not satisfactory. In this report, to improve the image quality, the parameters such as coincidence window was optimized to distinguish photon statistics effectively due to change in polarization angle and the objective lens was utilized to focus the entangled photon beams. These modifications enabled optical imaging by accurately detecting slight polarization variations in different media. It is suggested that the proposed method enables a superior imaging performance even in the presence of noise and low-power illumination requirement, offering new possibilities for high-quality imaging applications.
With the advancement of non-classical light sources such as single-photon and entangled-photon sources, innovative microscopy based on quantum principles has been proposed for traditional microscopy. This paper introduces the experimental demonstration of a quantum polarization microscopic technique that incorporates a quantum-entangled photon source. Although the point that employs the variation in polarization angle due to reflection or transmission at the sample is similar to classical polarization microscopy, the method for constructing the image contrast is significantly different. The image contrast is constructed by the coincidence count of signal and idler photons. In the case that the coincidence count is recorded from both the signal and idler photons, the photon statistics resemble a thermal state, similar to the blackbody radiation, but with a significantly higher peak intensity in the second-order autocorrelation function at zero delay that is derived from the coincidence count, while, when the coincidence count is taken from either the signal or idler photon only, although the photon state exhibits a thermal state again, the photon statistics become more dispersive and result in a lower peak intensity of the autocorrelation function. These different thermal states can be switched by slightly changing the photon polarization, which is suddenly aroused within a narrow range of the analyzer angle. The autocorrelation function g2(0) at the thermal state exhibits a sensitivity that is three times higher compared to the classical coincidence count rate, and this concept can be effectively utilized to enhance the contrast of the image. One of the key achievements of our proposed method is ensuring a low power of illumination (in the order of Pico-joules) for constructing the image. In addition, the robustness without any precise setup is also favorable for practical use. This polarization microscopic technique can provide a superior imaging technique compared to the classical method, opening a new frontier for research in material sciences, biology, and other fields requiring high-resolution imaging.
With the advancement of non-classical light sources such as single-photon and entangled-photon sources, innovative microscopy based on the quantum principles has been proposed over traditional microscopy. This paper introduces the experimental demonstration of a quantum polarization microscopic technique that incorporates a quantum-entangled photon source. Although the point that employs the variation of polarization angle due to reflection or transmission at the sample is similar to classical polarization microscopy, the method for constructing image contrast is significantly different. Image contrast is constructed by the coincidence count of signal and idler photons. In the case that coincidence count is recorded from both the signal and idler photons, the photon statistics resemble a thermal state, similar to the blackbody radiation, but with a significantly higher peak intensity in the second order autocorrelation function at zero delay that is derived from coincidence count. While, when the coincidence count is taken from either the signal or idler photon only, though the photon state exhibits a thermal state again, the photon statistics become more dispersive and result in a lower peak intensity of the autocorrelation function. These different thermal states can be switched by slightly changing the photon polarization, which is suddenly aroused within narrow range of analyzer angle. This polarization microscopic technique can provide a superior imaging technique compared to the classical method, opening a new frontier for research in material sciences, biology, and other fields requiring high-resolution imaging.
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.
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.
Quantum imaging is emerging as a transformative approach for biomedical applications, applying nonclassical properties of light, such as entanglement, squeezing, and quantum correlations, to overcome fundamental limits of conventional techniques. These methods promise superior spatial resolution, enhanced signal-to-noise ratios, improved phase sensitivity, and reduced radiation dose, for potentially safer and more precise imaging for delicate biological samples. Here, we present an overview of quantum optical biomedical imaging technologies as well as quantum-inspired imaging methods, including quantum optical coherence tomography, quantum optical microscopy, ghost imaging, multi-parameter quantum imaging, and imaging with quantum-grade cameras. We describe the operating principles, biomedical applications, and unique advantages of each approach, along with the specific challenges for their translation into real-life practice. This review aims to guide future research toward advancing quantum imaging from experimental demonstrations to impactful biomedical tools.