Optics Express

Imaging through strong external illumination via mode-error analysis

Jaesung Heo, Taek Jeong, Nam Hun Park, Su‐Yong Lee, Jihwan Kim, Duk Y. Kim, Zaeill Kim, Yonggi Jo

Published Aug 13, 2025• 1 citation

Abstract

In optical imaging, various techniques have been studied to mitigate unwanted light. Mode-selective detection, which filters out unwanted light modes, is widely used to reduce the impact of external light. However, this technique cannot completely reject external light when it shares the same mode as the desired light. In this paper, we analyze an image reconstruction method, called mode-error-based imaging (MEI), inspired by a recent study on quantum-secured imaging, to reject image corruption from external environments, including noise. MEI constructs a target image using an estimated reconstruction factor obtained by analyzing the source light mode and the measured light mode. We simulate the capacity and provide a proof-of-principle demonstration of MEI. We investigated the conditions for enhancing image quality under external illumination with MEI compared to the mode-selective method. We anticipate that existing post-processing techniques for noise reduction, such as machine learning, can also be used in parallel to improve image quality. The noise reduction capability of MEI can be utilized not only in imaging systems with strong background noise, such as microwave-based imaging, but also in imaging systems with weak probes, such as bioimaging.

DOI: 10.1364/oe.565562

Related papers

Smart Quantum Imaging

Ebrahim Karimi

The use of quantum properties of light has paved new avenues in the field of imaging. Quantum illumination and ghost-imaging protocols have shown exciting promise in addressing the issues inherent in classical imaging, such as background noise and a high level of required illumination. Moreover, quantum metrological schemes analyzing the modal content of light would address the resolution limits of direct imaging, promising enhancement beyond the Rayleigh limit. Augmenting these novel techniques with machine learning, particularly deep learning architectures such as Convolutional Neural Networks (CNNs), one strives to see significant improvements in image reconstruction and object identification in quantum imaging protocols. In my talk, I present recent progress and development on reconstructing the image of different objects with quantum sources, employing a high degree of spatial correlation between photon pairs and autoencoder deep learning architecture.

Photonics for Quantum (PfQ)Jul 15, 20210 citations

Imaging through noise with quantum illumination

T. Gregory, Paul‐Antoine Moreau, E. Toninelli +1 more

The contrast of an image can be degraded by the presence of background light and sensor noise. To overcome this degradation, quantum illumination protocols have been theorized that exploit the spatial correlations between photon pairs. Here, we demonstrate the first full-field imaging system using quantum illumination by an enhanced detection protocol. With our current technology, we achieve a rejection of background and stray light of up to 5.8 and also report an image contrast improvement up to a factor of 11, which is resilient to both environmental noise and transmission losses. The quantum illumination protocol differs from usual quantum schemes in that the advantage is maintained even in the presence of noise and loss. Our approach may enable laboratory-based quantum imaging to be applied to real-world applications where the suppression of background light and noise is important, such as imaging under low photon flux and quantum LIDAR.

arXiv:1907.09370Science AdvancesFeb 7, 2020189 citations

Noise rejection through an improved quantum illumination protocol

Thomas Gregory, Paul‐Antoine Moreau, Simon Peter Mekhail +2 more

Quantum illumination protocols can be implemented to improve imaging performance in the low photon flux regime even in the presence of both background light and sensor noise. However, the extent to which this noise can be rejected is limited by the rate of accidental correlations resulting from the detection of photon or noise events that are not quantum-correlated. Here we present an improved protocol that rejects up to [Formula: see text] of background light and sensor noise in the low photon flux regime, improving upon our previous results by an order of magnitude. This improvement, which requires no information regarding the scene or noise statistics, will enable extremely low light quantum imaging techniques to be applied in environments previously thought difficult and be an important addition to the development of covert imaging, quantum microscopes, and quantum LIDAR.

Scientific ReportsNov 8, 202130 citations

Noise-Resilient Imaging through Coherence Filtering

Pranay Mohta, Keval Moliya, Aniket Nag +2 more

Noise is a significant challenge in imaging. Conventional intensity-based techniques mitigate noise through various filtering methods, but they often require prior knowledge of noise characteristics and struggle, especially under low-light conditions and with spatially structured noise. Quantum distillation provides enhanced noise rejection; however, its applicability is limited as it requires specialised illumination and substantial modifications to existing imaging setups. In this article, we introduce a coherence-based image distillation approach that separates object from noise by leveraging the difference in their temporal coherence properties. We implement this through our interferometric protocol, which enables imaging based on spatial coherence while simultaneously filtering out noise via temporal coherence. This overcomes the limitations of both intensity-based and quantum distillation methods. We experimentally demonstrate noise resilience by successfully recovering feature-rich objects, such as QR codes and grayscale wheels, obscured by spatially uniform and structured noise 20 times as intense as the object. We further show that our method remains effective for fields with substantial spectral overlap, outperforming spectral filtering in regimes where the latter provides little noise suppression. This approach provides a robust framework for noise-resilient imaging with applications in optical communication, fluorescence microscopy, and biological imaging at both high and low light levels.

physics.opticsCross-listedarXiv:2605.09324May 12, 2026

Microscopy using quantum sources of illumination

Miles J. Padgett

We use entangled photons as the light source in a normal microscope. Using this quantum illumination improves both the resolution and noise rejection in the image. The resolution of any classical imaging system is limited by the diffraction created by the finite size of the imaging lens. By using a light source that emits pairs of entangled photons and carefully controlling a camera that is capable of detecting single photons it is possible to observe these photons arriving two-by-two. Applying camera analysis software to log only these two-by-two events one can form an image from the mid-point (bisector) of each of these pair events. The image formed from the sum of all these bisectors has an improved resolution that surpasses the classical limit. Another advantage of using a quantum illumination is that it allows the two-by-two events from entangled photon pairs to be distinguished from background (classical) light and sensor noise. When processed in this way the resulting image is free of camera noise and any background light may be eliminated. The use of a quantum illumination protocol such as that used here results in the elimination of background light and therefore allows the development of the optical equivalent of quantum radar – a quantum enhanced LIDAR scheme. Using quantum illumination, combined with commercially available cameras that are sensitive to single photons creates a new approach to super-resolution and low noise microscopy. Imaging through noise with quantum illumination, T Gregory, P-A Moreau, E Toninelli, and M J Padgett, Science Advances 6, eaay2652 (2020) Resolution-enhanced quantum imaging by centroid estimation of biphotons, E Toninelli, P-A Moreau, T Gregory, A Mihalyi, M Edgar, N Radwell, and M J Padgett, Optica 6, 347-353 (2019)

Photonics for Quantum (PfQ)Aug 27, 20210 citations

Low-cost quantum error mitigation via auxiliary qubit return validation

Gilad Kishony, Avi Elazari, Ron Cohen +1 more

We introduce a low-overhead technique for quantum error mitigation based on post-selection using auxiliary qubit measurements. The method exploits the structural property that, in an error-free computation, auxiliary qubits are often expected to return to the zero state after use. By selectively measuring these qubits at carefully chosen points in the circuit, erroneous shots can be identified and discarded, improving result fidelity with minimal hardware overhead. To account for circuit noise, including measurement errors, we analyze the likelihood that a measurement outcome indicates a corrupted shot. This analysis is informed by the measurement's backward light cone, namely the set of circuit operations that could affect the outcome. Shots whose auxiliary measurement outcomes imply a corruption likelihood above a tunable threshold are rejected. Simulations show that the method reduces the false-negative rate by approximately 10% while discarding only approximately 1% of valid shots. The threshold controls the bias-variance tradeoff inherent to post-selection, allowing the method to be adapted to the fidelity and sampling requirements of different applications.

quant-pharXiv:2605.28342May 28, 20260 citations