Pub Date : 2026-01-21DOI: 10.1016/j.optcom.2026.132925
Xiansheng Li, Jun Xin
Multimode quantum entangled states play a crucial role in quantum information processing. However, the generation of large-scale multimode quantum entanglement in the spatial degree of freedom remains a significant challenge. In this paper, we theoretically propose a scheme for generating spatial multimode entangled states through four-wave mixing processes. Our approach is based on the topology of an SU(1,1) interferometer (SUI). For an input beam with spatial modes exhibiting circular symmetry, we demonstrate that a -mode spatially entangled state can be generated by rotating the spatial modes of the beam in one arm of the SUI along the optical axis.
{"title":"Generating spatial multimode entanglement using a spatial-mode-rotated SU(1,1) interferometer: Theoretical study","authors":"Xiansheng Li, Jun Xin","doi":"10.1016/j.optcom.2026.132925","DOIUrl":"10.1016/j.optcom.2026.132925","url":null,"abstract":"<div><div>Multimode quantum entangled states play a crucial role in quantum information processing. However, the generation of large-scale multimode quantum entanglement in the spatial degree of freedom remains a significant challenge. In this paper, we theoretically propose a scheme for generating spatial multimode entangled states through four-wave mixing processes. Our approach is based on the topology of an SU(1,1) interferometer (SUI). For an input beam with <span><math><mi>n</mi></math></span> spatial modes exhibiting circular symmetry, we demonstrate that a <span><math><mrow><mn>2</mn><mi>n</mi></mrow></math></span>-mode spatially entangled state can be generated by rotating the spatial modes of the beam in one arm of the SUI along the optical axis.</div></div>","PeriodicalId":19586,"journal":{"name":"Optics Communications","volume":"607 ","pages":"Article 132925"},"PeriodicalIF":2.5,"publicationDate":"2026-01-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146080129","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-20DOI: 10.1016/j.optcom.2026.132917
Yonghong Wang , Zhuoyan Wang , Yanfeng Yao , Junrui Li
To address the problems of fringe merging and loss of fringe edge information during the denoising of high-density fringe patterns in digital speckle pattern interferometry (DSPI), which seriously affects the phase reconstruction and measurement precision, a hierarchical adaptive curvelet thresholding with sine-cosine transform (HACuT) is proposed in this paper. By incorporating subband-wise noise energy estimation in the curvelet domain, local statistical constraints derived from clean image curvelet coefficients, and hierarchical scale-dependent adjustment, an adaptive thresholding scheme is constructed to enable precise and robust regulation of curvelet coefficients. Moreover, a smooth thresholding function based on the hyperbolic tangent is designed to enhance denoising stability. Simulation and experimental results demonstrate that the proposed method effectively suppresses noise, preserves fringe edge integrity, and maintains high computational efficiency, confirming its practical applicability.
{"title":"Multi-scale based approach for denoising digital speckle pattern interferometry fringe patterns using curvelet thresholding","authors":"Yonghong Wang , Zhuoyan Wang , Yanfeng Yao , Junrui Li","doi":"10.1016/j.optcom.2026.132917","DOIUrl":"10.1016/j.optcom.2026.132917","url":null,"abstract":"<div><div>To address the problems of fringe merging and loss of fringe edge information during the denoising of high-density fringe patterns in digital speckle pattern interferometry (DSPI), which seriously affects the phase reconstruction and measurement precision, a hierarchical adaptive curvelet thresholding with sine-cosine transform (HACuT) is proposed in this paper. By incorporating subband-wise noise energy estimation in the curvelet domain, local statistical constraints derived from clean image curvelet coefficients, and hierarchical scale-dependent adjustment, an adaptive thresholding scheme is constructed to enable precise and robust regulation of curvelet coefficients. Moreover, a smooth thresholding function based on the hyperbolic tangent is designed to enhance denoising stability. Simulation and experimental results demonstrate that the proposed method effectively suppresses noise, preserves fringe edge integrity, and maintains high computational efficiency, confirming its practical applicability.</div></div>","PeriodicalId":19586,"journal":{"name":"Optics Communications","volume":"607 ","pages":"Article 132917"},"PeriodicalIF":2.5,"publicationDate":"2026-01-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146025930","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-20DOI: 10.1016/j.optcom.2026.132929
Fanmiao Meng, Weiwei Yu
and are the fundamental models in intense laser field, facilitating the investigation of attosecond electron dynamics, the observation of nuclear wave packet evolution, and the implementation of frequency-modulated high-order harmonic generation. In this work, the high-order harmonic generation dynamics of and , under terahertz field assistance and the nuclear motion, were investigated by using numerical solutions of the non-Born–Oppenheimer time-dependent Schrödinger equation. Terahertz assistance increases the peak intensity of the central electric field while maintaining the shape of the electric field, consequently significantly extending the harmonic cutoff range and generating three distinct plateau regions. Upon considering non-Born–Oppenheimer approximation, the asymmetry of the electron cloud amplifies the interaction between electrons and nuclei, the nuclear motion is relatively slow, so the nuclei remain within the Franck–Condon region. Thus, the efficiency of the harmonic is three orders of magnitude greater than that of . These findings provide new perspectives on the microscopic principles of terahertz-assisted high-order harmonic generation and clarify the impact of nuclear motion on this phenomenon.
{"title":"Investigating the effect of nuclear motion on the high-order harmonic generation efficiency of H2+ and HD+ molecules under terahertz assistance","authors":"Fanmiao Meng, Weiwei Yu","doi":"10.1016/j.optcom.2026.132929","DOIUrl":"10.1016/j.optcom.2026.132929","url":null,"abstract":"<div><div><span><math><msubsup><mrow><mi>H</mi></mrow><mrow><mn>2</mn></mrow><mrow><mo>+</mo></mrow></msubsup></math></span> and <span><math><msup><mrow><mi>HD</mi></mrow><mrow><mo>+</mo></mrow></msup></math></span> are the fundamental models in intense laser field, facilitating the investigation of attosecond electron dynamics, the observation of nuclear wave packet evolution, and the implementation of frequency-modulated high-order harmonic generation. In this work, the high-order harmonic generation dynamics of <span><math><msubsup><mrow><mi>H</mi></mrow><mrow><mn>2</mn></mrow><mrow><mo>+</mo></mrow></msubsup></math></span> and <span><math><msup><mrow><mi>HD</mi></mrow><mrow><mo>+</mo></mrow></msup></math></span>, under terahertz field assistance and the nuclear motion, were investigated by using numerical solutions of the non-Born–Oppenheimer time-dependent Schrödinger equation. Terahertz assistance increases the peak intensity of the central electric field while maintaining the shape of the electric field, consequently significantly extending the harmonic cutoff range and generating three distinct plateau regions. Upon considering non-Born–Oppenheimer approximation, the asymmetry of the electron cloud amplifies the interaction between electrons and nuclei, the nuclear motion is relatively slow, so the nuclei remain within the Franck–Condon region. Thus, the efficiency of the <span><math><msubsup><mrow><mi>H</mi></mrow><mrow><mn>2</mn></mrow><mrow><mo>+</mo></mrow></msubsup></math></span> harmonic is three orders of magnitude greater than that of <span><math><msup><mrow><mi>HD</mi></mrow><mrow><mo>+</mo></mrow></msup></math></span>. These findings provide new perspectives on the microscopic principles of terahertz-assisted high-order harmonic generation and clarify the impact of nuclear motion on this phenomenon.</div></div>","PeriodicalId":19586,"journal":{"name":"Optics Communications","volume":"607 ","pages":"Article 132929"},"PeriodicalIF":2.5,"publicationDate":"2026-01-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146026029","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-20DOI: 10.1016/j.optcom.2026.132940
Yu E. Geints
Quantum dot superparticles are a specific class of metamaterials created through the self-assembly of nanometer semiconductor quantum dots into organized micro-scale structures, such as microspheres. Superparticles exhibit unique optical, chemical, and electronic properties. These properties are not merely the sum of the constituent quantum dots but rather bear the signature of the collective behavior of the nanoscale building blocks. In particular, assembling an ensemble of quantum dots into a super-sphere allows them to function as a single, high-quality optical resonator. This structure efficiently confines the emission from the pump-excited quantum dots via whispering gallery modes. The emissive properties of such a superparticle resonator remain an area of active investigation. Using numerical simulation, we study the angular structure of the photoluminescence from superparticles of various sizes and architectures formed from CdS quantum dots. We show that, in general, the angular distribution of the SP emission is characterized by strong asymmetry, with a maximum in the backward direction relative to the incident pump beam. In contrast, this asymmetry is virtually absent in the forward and side-scattering directions. The excitation of resonant modes in the superparticle enhances the emission intensity and reduces the degree of its backward asymmetry. Furthermore, coating the CdS quantum dot particle with a silicon dioxide layer increases the probability of exciting field resonances in such a core-shell superparticle.
{"title":"Angular patterns of photoluminescence in quantum dot spherical superparticles mediated by whispering-gallery modes","authors":"Yu E. Geints","doi":"10.1016/j.optcom.2026.132940","DOIUrl":"10.1016/j.optcom.2026.132940","url":null,"abstract":"<div><div>Quantum dot superparticles are a specific class of metamaterials created through the self-assembly of nanometer semiconductor quantum dots into organized micro-scale structures, such as microspheres. Superparticles exhibit unique optical, chemical, and electronic properties. These properties are not merely the sum of the constituent quantum dots but rather bear the signature of the collective behavior of the nanoscale building blocks. In particular, assembling an ensemble of quantum dots into a super-sphere allows them to function as a single, high-quality optical resonator. This structure efficiently confines the emission from the pump-excited quantum dots via whispering gallery modes. The emissive properties of such a superparticle resonator remain an area of active investigation. Using numerical simulation, we study the angular structure of the photoluminescence from superparticles of various sizes and architectures formed from CdS quantum dots. We show that, in general, the angular distribution of the SP emission is characterized by strong asymmetry, with a maximum in the backward direction relative to the incident pump beam. In contrast, this asymmetry is virtually absent in the forward and side-scattering directions. The excitation of resonant modes in the superparticle enhances the emission intensity and reduces the degree of its backward asymmetry. Furthermore, coating the CdS quantum dot particle with a silicon dioxide layer increases the probability of exciting field resonances in such a core-shell superparticle.</div></div>","PeriodicalId":19586,"journal":{"name":"Optics Communications","volume":"607 ","pages":"Article 132940"},"PeriodicalIF":2.5,"publicationDate":"2026-01-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146025928","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Optical tweezers have been widely used for manipulating micro- and nanoparticles, yet conventional trapping systems often demand high optical power and complex focusing configurations. In this work, a low-power optical trapping approach is proposed using an all-dielectric slotted dimer metasurface that supports anapole-enhanced near fields. By taking advantage of the non-radiative interference between electric and toroidal dipoles, strong field confinement and steep intensity gradients are obtained, significantly enhancing the optical gradient force. Numerical simulations confirm that 20 nm-radius nanoparticles can be stably trapped at a power density of 120 μW/μm2, about one order of magnitude lower than conventional schemes. These findings reveal the physical mechanism of anapole-assisted trapping and offer a promising route for low-power, thermally stable optical manipulation.
{"title":"Anapole-enhanced local fields for low-power optical trapping in all-dielectric metasurfaces","authors":"Yewen Mei, Junqiao Wang, Qiaoqiao Wang, Mengsha Xue, Jiangnan He, Jinyuan Yang","doi":"10.1016/j.optcom.2026.132938","DOIUrl":"10.1016/j.optcom.2026.132938","url":null,"abstract":"<div><div>Optical tweezers have been widely used for manipulating micro- and nanoparticles, yet conventional trapping systems often demand high optical power and complex focusing configurations. In this work, a low-power optical trapping approach is proposed using an all-dielectric slotted dimer metasurface that supports anapole-enhanced near fields. By taking advantage of the non-radiative interference between electric and toroidal dipoles, strong field confinement and steep intensity gradients are obtained, significantly enhancing the optical gradient force. Numerical simulations confirm that 20 nm-radius nanoparticles can be stably trapped at a power density of 120 μW/μm<sup>2</sup>, about one order of magnitude lower than conventional schemes. These findings reveal the physical mechanism of anapole-assisted trapping and offer a promising route for low-power, thermally stable optical manipulation.</div></div>","PeriodicalId":19586,"journal":{"name":"Optics Communications","volume":"607 ","pages":"Article 132938"},"PeriodicalIF":2.5,"publicationDate":"2026-01-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146026022","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-20DOI: 10.1016/j.optcom.2026.132937
Yunfeng Li , Eneko Lopez , Jaione Etxebarria-Elezgarai , Andreas Seifert
Accurate laser beam profiling is the basis for alignment, focusing, and power delivery, but measurements are often distorted by finite apertures, limited axial scanning, and hardware limitations. We present a pinhole + single-pixel method for Gaussian beam profiling that combines multi-plane fitting of the propagation radius with an explicit finite-aperture model and a regularized, band-limited deconvolution. By fitting the beam propagation curve to measured beam radii along many axial positions, robust estimates of the beam waist and its position are obtained, avoiding bias caused by approaches that only consider divergence angle measurements. An operational rule based on the waist-to-aperture ratio indicates when convolution bias is negligible and when safeguarded deconvolution without 4 undershoot is beneficial. The workflow supports free-space and lens-assisted configurations with uncertainty propagation, is wavelength-agnostic via detector substitution, and remains cost-effective.
{"title":"Accurate and low-cost Gaussian beam profiling with pinhole and single-pixel detector","authors":"Yunfeng Li , Eneko Lopez , Jaione Etxebarria-Elezgarai , Andreas Seifert","doi":"10.1016/j.optcom.2026.132937","DOIUrl":"10.1016/j.optcom.2026.132937","url":null,"abstract":"<div><div>Accurate laser beam profiling is the basis for alignment, focusing, and power delivery, but measurements are often distorted by finite apertures, limited axial scanning, and hardware limitations. We present a pinhole<!--> <!-->+<!--> <!-->single-pixel method for Gaussian beam profiling that combines multi-plane fitting of the propagation radius with an explicit finite-aperture model and a regularized, band-limited deconvolution. By fitting the beam propagation curve to measured beam radii along many axial positions, robust estimates of the beam waist and its position are obtained, avoiding bias caused by approaches that only consider divergence angle measurements. An operational rule based on the waist-to-aperture ratio <span><math><mrow><msub><mrow><mi>w</mi></mrow><mrow><mn>0</mn></mrow></msub><mo>/</mo><mi>d</mi></mrow></math></span> indicates when convolution bias is negligible and when safeguarded deconvolution without 4<span><math><mi>σ</mi></math></span> undershoot is beneficial. The workflow supports free-space and lens-assisted configurations with uncertainty propagation, is wavelength-agnostic via detector substitution, and remains cost-effective.</div></div>","PeriodicalId":19586,"journal":{"name":"Optics Communications","volume":"607 ","pages":"Article 132937"},"PeriodicalIF":2.5,"publicationDate":"2026-01-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146026024","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-19DOI: 10.1016/j.optcom.2026.132928
Chupeng Lu , Xiaoyang Li , Xinyu Yang , Xinhang Xu , Hang Jiang , Tao Geng , Libo Yuan
In this paper, a polarization-multiplexed long-period fiber grating (LPFG) sensor capable of simultaneous curvature, torsion, and temperature measurements is proposed for fiber-based shape sensing. The sensor is fabricated by CO2 laser inscription on a pre-twisted composite fiber structure comprising a polarization-maintaining fiber (PMF) fusion-spliced between two single-mode fibers (SMFs). The synergistic effects of pre-twist and CO2 laser induced thermal stress significantly modify the internal stress distribution of the PMF, thereby enhancing its elliptical birefringence. This enhancement results in pronounced polarization-dependent resonant wavelengths and sensitivities. The fabricated PMF-LPFG exhibits distinct resonant wavelengths of 1547.4 nm and 1525.6 nm when the input light is aligned with the slow axis (0°) and fast axis (90°), respectively. Experimental results demonstrate that the proposed sensor achieves a maximum torsion sensitivity of 2.24 nm/(rad/m) and a maximum curvature sensitivity of 45.68 nm/m−1 at 0° polarization, with a corresponding temperature sensitivity of 108.9 p.m./°C. Owing to its compact structure, high sensitivity, and polarization-multiplexing capability, the proposed sensor demonstrates strong potential for practical three-dimensional shape sensing applications.
{"title":"Polarization-multiplexed fiber grating sensor with enhanced birefringence for shape sensing applications","authors":"Chupeng Lu , Xiaoyang Li , Xinyu Yang , Xinhang Xu , Hang Jiang , Tao Geng , Libo Yuan","doi":"10.1016/j.optcom.2026.132928","DOIUrl":"10.1016/j.optcom.2026.132928","url":null,"abstract":"<div><div>In this paper, a polarization-multiplexed long-period fiber grating (LPFG) sensor capable of simultaneous curvature, torsion, and temperature measurements is proposed for fiber-based shape sensing. The sensor is fabricated by CO<sub>2</sub> laser inscription on a pre-twisted composite fiber structure comprising a polarization-maintaining fiber (PMF) fusion-spliced between two single-mode fibers (SMFs). The synergistic effects of pre-twist and CO<sub>2</sub> laser induced thermal stress significantly modify the internal stress distribution of the PMF, thereby enhancing its elliptical birefringence. This enhancement results in pronounced polarization-dependent resonant wavelengths and sensitivities. The fabricated PMF-LPFG exhibits distinct resonant wavelengths of 1547.4 nm and 1525.6 nm when the input light is aligned with the slow axis (0°) and fast axis (90°), respectively. Experimental results demonstrate that the proposed sensor achieves a maximum torsion sensitivity of 2.24 nm/(rad/m) and a maximum curvature sensitivity of 45.68 nm/m<sup>−1</sup> at 0° polarization, with a corresponding temperature sensitivity of 108.9 p.m./°C. Owing to its compact structure, high sensitivity, and polarization-multiplexing capability, the proposed sensor demonstrates strong potential for practical three-dimensional shape sensing applications.</div></div>","PeriodicalId":19586,"journal":{"name":"Optics Communications","volume":"607 ","pages":"Article 132928"},"PeriodicalIF":2.5,"publicationDate":"2026-01-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146026026","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-18DOI: 10.1016/j.optcom.2026.132927
Daehyun Kim , Hayato Otsu , Masato Tsujiguchi , Naoki Fujita , Maria Vanessa Balois-Oguchi , Kotaro Kajikawa
Novel designs of a Kretschmann-type surface plasmon resonance (SPR) platform are presented, in which surface plasmons are excited by light incident parallel or perpendicular to the prism-metal interface, using a prism with a high refractive index of approximately 2.0. These designs enable us to miniaturize the optical setup, as the SPR condition can be achieved without the need for a rotation mechanism. The refractive index of water–ethanol mixtures with various mixture ratios was measured, and the formation process of a self-assembled monolayer was observed to demonstrate the adequacy of our design.
{"title":"Surface plasmon resonance excited using Kretschmann configuration with high refractive-index-prism","authors":"Daehyun Kim , Hayato Otsu , Masato Tsujiguchi , Naoki Fujita , Maria Vanessa Balois-Oguchi , Kotaro Kajikawa","doi":"10.1016/j.optcom.2026.132927","DOIUrl":"10.1016/j.optcom.2026.132927","url":null,"abstract":"<div><div>Novel designs of a Kretschmann-type surface plasmon resonance (SPR) platform are presented, in which surface plasmons are excited by light incident parallel or perpendicular to the prism-metal interface, using a prism with a high refractive index of approximately 2.0. These designs enable us to miniaturize the optical setup, as the SPR condition can be achieved without the need for a rotation mechanism. The refractive index of water–ethanol mixtures with various mixture ratios was measured, and the formation process of a self-assembled monolayer was observed to demonstrate the adequacy of our design.</div></div>","PeriodicalId":19586,"journal":{"name":"Optics Communications","volume":"607 ","pages":"Article 132927"},"PeriodicalIF":2.5,"publicationDate":"2026-01-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146025929","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-16DOI: 10.1016/j.optcom.2026.132926
Yi Qin , Yueyou Li , Qiong Gong , Liming Zhang , Chao Liu , Wei Liu
The scattering-imaging-based encryption (SIBE) employs spatially incoherent illumination and exploits the optical memory effect (OME) inherent in the scattering media, offering significant benefits such as immunity to speckle noise and highly compact system designs. Nevertheless, the OME imposes a constraint on the maximum plaintext size that the cryptosystem can process in a single acquisition. The present research indicates that a well-trained deep neural network (DNN) is potentially able to retrieve the plaintext directly from the ciphertext. However, due to its large size, the DNN is inconvenient for transmission and distribution, making it unsuitable for use as the secret key. In this paper, we propose a cross-modality SIBE (CM-SIBE) approach by employing deep learning. We construct two encryption schemes: a real SIBE (R-SIBE) and a virtual SIBE (V-SIBE). For convenience, their corresponding ciphertexts and PSFs are denoted as R-Ciphertext and R-PSF for the real scheme, and V-Ciphertext and V-PSF for the virtual one, respectively. We encrypt the plaintext with the R-SIBE and take the R-Ciphertext as the final ciphertext. However, we take the V-PSF as the secret key. For successful decryption, we train a DNN to convert the R-Ciphertext into its corresponding V-Ciphertext; the two ciphertexts are derived from the same plaintext. It is important to note that the V-PSF acts as the sole secret key, while the DNN serves as an auxiliary tool. For decryption, an authorized user first transforms the ciphertext into the V-Ciphertext using the DNN. Subsequently, the user deconvolves the V-Ciphertext with the V-PSF to retrieve the original plaintext. Our CM-SIBE ensures high-quality decryption of large-sized plaintexts that surpass the OME limit of the diffuser, while also circumventing the need for a bulky DNN as the secret key. Furthermore, our method is robust against known ciphertext-only (COA), while also demonstrating high resilience to noise and occlusion.
{"title":"Cross-modality scattering-imaging-based encryption by deep learning","authors":"Yi Qin , Yueyou Li , Qiong Gong , Liming Zhang , Chao Liu , Wei Liu","doi":"10.1016/j.optcom.2026.132926","DOIUrl":"10.1016/j.optcom.2026.132926","url":null,"abstract":"<div><div>The scattering-imaging-based encryption (SIBE) employs spatially incoherent illumination and exploits the optical memory effect (OME) inherent in the scattering media, offering significant benefits such as immunity to speckle noise and highly compact system designs. Nevertheless, the OME imposes a constraint on the maximum plaintext size that the cryptosystem can process in a single acquisition. The present research indicates that a well-trained deep neural network (DNN) is potentially able to retrieve the plaintext directly from the ciphertext. However, due to its large size, the DNN is inconvenient for transmission and distribution, making it unsuitable for use as the secret key. In this paper, we propose a cross-modality SIBE (CM-SIBE) approach by employing deep learning. We construct two encryption schemes: a real SIBE (R-SIBE) and a virtual SIBE (V-SIBE). For convenience, their corresponding ciphertexts and PSFs are denoted as R-Ciphertext and R-PSF for the real scheme, and V-Ciphertext and V-PSF for the virtual one, respectively. We encrypt the plaintext with the R-SIBE and take the R-Ciphertext as the final ciphertext. However, we take the V-PSF as the secret key. For successful decryption, we train a DNN to convert the R-Ciphertext into its corresponding V-Ciphertext; the two ciphertexts are derived from the same plaintext. It is important to note that the V-PSF acts as the sole secret key, while the DNN serves as an auxiliary tool. For decryption, an authorized user first transforms the ciphertext into the V-Ciphertext using the DNN. Subsequently, the user deconvolves the V-Ciphertext with the V-PSF to retrieve the original plaintext. Our CM-SIBE ensures high-quality decryption of large-sized plaintexts that surpass the OME limit of the diffuser, while also circumventing the need for a bulky DNN as the secret key. Furthermore, our method is robust against known ciphertext-only (COA), while also demonstrating high resilience to noise and occlusion.</div></div>","PeriodicalId":19586,"journal":{"name":"Optics Communications","volume":"606 ","pages":"Article 132926"},"PeriodicalIF":2.5,"publicationDate":"2026-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146039242","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-16DOI: 10.1016/j.optcom.2026.132924
Lixun Sun , Yanxiong Yang , Yuyang Xiao , Yuquan Zhang , Xiaocong Yuan , Ting Mei
Extending the low-loss polariton response of graphene into the visible waveband is of significant interest for advancing applications in nanophotonics and optoelectronics. However, the challenge arises from the relatively low conductivity of graphene in this regime when coupled with common material properties. We reveal that a promising solution involves understanding and optimizing the influence of the dielectric environment on polariton excitation. In this work, both theoretical prediction and experimental evidence are presented, confirming the existence of transverse-electric surface polaritons in graphene within the visible waveband. This discovery is grounded in the optical admittance matching condition, providing a practical approach for achieving complete conversion of excitation photons into surface polaritons at designated wavelengths and incidence angles. By ensuring precise wavevector matching, the polaritons supported by structures specifically optimized for admittance matching exhibit theoretically attenuation-free propagation characteristics. This advancement holds promise for developing ultralow-loss polaritonic devices in the visible and near-infrared ranges.
{"title":"Perfect excitation of graphene surface polaritons in visible waveband","authors":"Lixun Sun , Yanxiong Yang , Yuyang Xiao , Yuquan Zhang , Xiaocong Yuan , Ting Mei","doi":"10.1016/j.optcom.2026.132924","DOIUrl":"10.1016/j.optcom.2026.132924","url":null,"abstract":"<div><div>Extending the low-loss polariton response of graphene into the visible waveband is of significant interest for advancing applications in nanophotonics and optoelectronics. However, the challenge arises from the relatively low conductivity of graphene in this regime when coupled with common material properties. We reveal that a promising solution involves understanding and optimizing the influence of the dielectric environment on polariton excitation. In this work, both theoretical prediction and experimental evidence are presented, confirming the existence of transverse-electric surface polaritons in graphene within the visible waveband. This discovery is grounded in the optical admittance matching condition, providing a practical approach for achieving complete conversion of excitation photons into surface polaritons at designated wavelengths and incidence angles. By ensuring precise wavevector matching, the polaritons supported by structures specifically optimized for admittance matching exhibit theoretically attenuation-free propagation characteristics. This advancement holds promise for developing ultralow-loss polaritonic devices in the visible and near-infrared ranges.</div></div>","PeriodicalId":19586,"journal":{"name":"Optics Communications","volume":"607 ","pages":"Article 132924"},"PeriodicalIF":2.5,"publicationDate":"2026-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146025927","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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