Pub Date : 2026-06-01Epub 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":"2026-06-01","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 : 2026-06-01Epub Date: 2026-01-12DOI: 10.1016/j.optcom.2026.132901
Peng Song, Le Li, Chengtao Liu, Lijian Zhang, Hua Guo
To address the intrinsic limitations imposed by the low received signal strength and the consequent restrictions on coverage range, in ultraviolet non-line-of-sight (UV NLOS) communication, this study establishes a three-dimensional spatial light-field distribution model for ultraviolet reflective channels. By integrating bidirectional reflectance distribution function (BRDF) theory with light reflection theory for rough surfaces, we calculate the reflectivity of ultraviolet light reflected from such surfaces and develop a three-stage physical model that characterizes the energy transfer of ultraviolet photons via a reflective surface to a sampling point. A Monte Carlo method is proposed to compute the three-dimensional spatial distribution of the ultraviolet reflection channel. Experimental verification employs a combined micro- and macro-scale approach. At the microscopic level, experiments confirm the accuracy of the BRDF model for cement surfaces within the solar-blind band under varying incident and reflection azimuth angles. At the macroscopic level, field experiments, supplemented by light-field simulations, reveal the effects of LED divergence angle and transmitter elevation angle on the energy distribution of the reflected light-field. The strong correlation between experimental and simulation results verifies the effectiveness of the proposed reflected light-field calculation method. This study provides a new approach for overcoming the distance bottleneck in UV NLOS communication and offers valuable insights for the design of covert communication systems in complex environments.
{"title":"Light-field distribution analysis in reflective ultraviolet communication channels","authors":"Peng Song, Le Li, Chengtao Liu, Lijian Zhang, Hua Guo","doi":"10.1016/j.optcom.2026.132901","DOIUrl":"10.1016/j.optcom.2026.132901","url":null,"abstract":"<div><div>To address the intrinsic limitations imposed by the low received signal strength and the consequent restrictions on coverage range, in ultraviolet non-line-of-sight (UV NLOS) communication, this study establishes a three-dimensional spatial light-field distribution model for ultraviolet reflective channels. By integrating bidirectional reflectance distribution function (BRDF) theory with light reflection theory for rough surfaces, we calculate the reflectivity of ultraviolet light reflected from such surfaces and develop a three-stage physical model that characterizes the energy transfer of ultraviolet photons via a reflective surface to a sampling point. A Monte Carlo method is proposed to compute the three-dimensional spatial distribution of the ultraviolet reflection channel. Experimental verification employs a combined micro- and macro-scale approach. At the microscopic level, experiments confirm the accuracy of the BRDF model for cement surfaces within the solar-blind band under varying incident and reflection azimuth angles. At the macroscopic level, field experiments, supplemented by light-field simulations, reveal the effects of LED divergence angle and transmitter elevation angle on the energy distribution of the reflected light-field. The strong correlation between experimental and simulation results verifies the effectiveness of the proposed reflected light-field calculation method. This study provides a new approach for overcoming the distance bottleneck in UV NLOS communication and offers valuable insights for the design of covert communication systems in complex environments.</div></div>","PeriodicalId":19586,"journal":{"name":"Optics Communications","volume":"606 ","pages":"Article 132901"},"PeriodicalIF":2.5,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145981661","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 : 2026-06-01Epub Date: 2026-01-12DOI: 10.1016/j.optcom.2026.132908
Jie Zhao , Zizhuo Li , Zhenxing Sun , Yanqiu Xu , Jin Zhang , Kaifei Tang , Jiaqiang Nie , Rulei Xiao , Xiangfei Chen
In this work, we present a high-order colliding pulse mode-locked lasers (CPML) based on a 500 μm cavity length Fabry-Perot saturable absorber (FP-SA) unit operating in the C-band. The laser employs a high-power epitaxial structure and asymmetric reflectance coatings, featuring a 95 % high-reflective (HR) coating on one facet and a naturally cleaved facet on the other. This design enhances intracavity energy density, optimizes pulse compression, and achieves cavity-length extension and performance refinement through modular multi-stage cascading. We systematically investigate the mode-locking dynamics of the SA-FP unit and cascaded systems (second to fourth order), demonstrating stable generation of optical pulses with 88.2 GHz longitudinal mode spacing and robust stability against current and temperature variations. Furthermore, to enable high-speed transmission on individual comb lines, a four-channel DWDM experiment is conducted at the 4th-order CPML’s central wavelength. Utilizing a thin-film LiNbO3 Mach-Zehnder interferometer (MZI) modulator, each channel achieve 25 Gb/s non-return-to-zero (NRZ) modulation capability. The proposed high-order CPML architecture serves as a superior comb source for energy-efficient optical interconnects and high-bandwidth data transmission, offering a scalable platform for next-generation photonic systems.
{"title":"High-order colliding-pulse mode-locked lase with high power and mode stability for optical I/O technology","authors":"Jie Zhao , Zizhuo Li , Zhenxing Sun , Yanqiu Xu , Jin Zhang , Kaifei Tang , Jiaqiang Nie , Rulei Xiao , Xiangfei Chen","doi":"10.1016/j.optcom.2026.132908","DOIUrl":"10.1016/j.optcom.2026.132908","url":null,"abstract":"<div><div>In this work, we present a high-order colliding pulse mode-locked lasers (CPML) based on a 500 μm cavity length Fabry-Perot saturable absorber (FP-SA) unit operating in the C-band. The laser employs a high-power epitaxial structure and asymmetric reflectance coatings, featuring a 95 % high-reflective (HR) coating on one facet and a naturally cleaved facet on the other. This design enhances intracavity energy density, optimizes pulse compression, and achieves cavity-length extension and performance refinement through modular multi-stage cascading. We systematically investigate the mode-locking dynamics of the SA-FP unit and cascaded systems (second to fourth order), demonstrating stable generation of optical pulses with 88.2 GHz longitudinal mode spacing and robust stability against current and temperature variations. Furthermore, to enable high-speed transmission on individual comb lines, a four-channel DWDM experiment is conducted at the 4th-order CPML’s central wavelength. Utilizing a thin-film LiNbO<sub>3</sub> Mach-Zehnder interferometer (MZI) modulator, each channel achieve 25 Gb/s non-return-to-zero (NRZ) modulation capability. The proposed high-order CPML architecture serves as a superior comb source for energy-efficient optical interconnects and high-bandwidth data transmission, offering a scalable platform for next-generation photonic systems.</div></div>","PeriodicalId":19586,"journal":{"name":"Optics Communications","volume":"606 ","pages":"Article 132908"},"PeriodicalIF":2.5,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145981668","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}
Mode division multiplexing (MDM) technology has been regarded as one of the most effective methods capable of improving fiber transmission capacity. In the case, modal crosstalk in few-mode fibers and nodes would become the potential limiting factor of long-haul fiber transmission and large network coverage. We propose an all-optical crosstalk suppression scheme based on a single semiconductor optical amplifier (SOA), with application to the optical MDM switching nodes. The feasibility of this scheme is experimentally demonstrated by optimizing the injection current, pump-to-signal power ratio (PSPR) and input signal-to-crosstalk ratio (SXR). The suppression performance for identical-frequency crosstalk is evaluated by inserting the single-SOA regenerator into a two-mode switching node and the error vector magnitude (EVM) for 10 Gb/s QPSK signals can be reduced by 13 % relative to the case without regeneration when the input SXR is 6 dB. On the basis of the single-SOA regenerator, the cascading performance of switching nodes and a double-stage SOA scheme for wavelength preserving are also discussed by simulation. It is shown that the SOA-based crosstalk suppression scheme is applied to the future multi-dimensional switching nodes and networks.
{"title":"Crosstalk suppression in mode-division-multiplexing optical switching nodes using a single SOA-based regenerator","authors":"Xinyu Ma, Baojian Wu, Xintong Lu, Yanjun Chen, Yihan Wang, Feng Wen, Kun Qiu","doi":"10.1016/j.optcom.2026.132945","DOIUrl":"10.1016/j.optcom.2026.132945","url":null,"abstract":"<div><div>Mode division multiplexing (MDM) technology has been regarded as one of the most effective methods capable of improving fiber transmission capacity. In the case, modal crosstalk in few-mode fibers and nodes would become the potential limiting factor of long-haul fiber transmission and large network coverage. We propose an all-optical crosstalk suppression scheme based on a single semiconductor optical amplifier (SOA), with application to the optical MDM switching nodes. The feasibility of this scheme is experimentally demonstrated by optimizing the injection current, pump-to-signal power ratio (PSPR) and input signal-to-crosstalk ratio (SXR). The suppression performance for identical-frequency crosstalk is evaluated by inserting the single-SOA regenerator into a two-mode switching node and the error vector magnitude (EVM) for 10 Gb/s QPSK signals can be reduced by 13 % relative to the case without regeneration when the input SXR is 6 dB. On the basis of the single-SOA regenerator, the cascading performance of switching nodes and a double-stage SOA scheme for wavelength preserving are also discussed by simulation. It is shown that the SOA-based crosstalk suppression scheme is applied to the future multi-dimensional switching nodes and networks.</div></div>","PeriodicalId":19586,"journal":{"name":"Optics Communications","volume":"607 ","pages":"Article 132945"},"PeriodicalIF":2.5,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146080068","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 : 2026-06-01Epub Date: 2026-01-29DOI: 10.1016/j.optcom.2026.132963
Mengmeng Shen , Jiacheng Luo , Fengjuan Chen , Haihua Zhang , Yong Li
It plays a crucial role in virtual reality (VR) and augmented reality (AR) to accurately capture and display real-world three-dimensional (3D) scene. In order to achieve this goal, we propose a new method based on deep-learning to convert deformed fringe in fringe projection profilometry (FPP) to computer-generated hologram (CGH). Three deep neural networks (DNNs) with the same basic structure are designed and trained with three datasets. The intensity information of real scene from a deformed fringe pattern is obtained with the first deep neural network (DNN1) and the phase of deformed fringe is obtained with the second one (DNN2). The hologram is generated from intensity information and phase difference of deformed fringe with the third deep neural network (DNN3). The phase difference is obtained by subtracting reference phase from absolute phase which is obtained with the three-frequency heterodyne algorithm. To improve the efficiency of dataset construction, a new transfer learning approach is proposed. The DNNs are firstly trained with datasets consisting of massive high-fidelity simulated data and then trained with datasets consisting of a small amount of real data. The simulated data are generated using the mathematical model of FPP system and the parameters obtained by system calibration, with ambient illumination, shadows and occlusion considered. Experimental results demonstrate the effectiveness and reliability of the proposed method.
{"title":"Accurate capture and display of real-world three-dimensional scene using fringe projection and deep-learning","authors":"Mengmeng Shen , Jiacheng Luo , Fengjuan Chen , Haihua Zhang , Yong Li","doi":"10.1016/j.optcom.2026.132963","DOIUrl":"10.1016/j.optcom.2026.132963","url":null,"abstract":"<div><div>It plays a crucial role in virtual reality (VR) and augmented reality (AR) to accurately capture and display real-world three-dimensional (3D) scene. In order to achieve this goal, we propose a new method based on deep-learning to convert deformed fringe in fringe projection profilometry (FPP) to computer-generated hologram (CGH). Three deep neural networks (DNNs) with the same basic structure are designed and trained with three datasets. The intensity information of real scene from a deformed fringe pattern is obtained with the first deep neural network (DNN1) and the phase of deformed fringe is obtained with the second one (DNN2). The hologram is generated from intensity information and phase difference of deformed fringe with the third deep neural network (DNN3). The phase difference is obtained by subtracting reference phase from absolute phase which is obtained with the three-frequency heterodyne algorithm. To improve the efficiency of dataset construction, a new transfer learning approach is proposed. The DNNs are firstly trained with datasets consisting of massive high-fidelity simulated data and then trained with datasets consisting of a small amount of real data. The simulated data are generated using the mathematical model of FPP system and the parameters obtained by system calibration, with ambient illumination, shadows and occlusion considered. Experimental results demonstrate the effectiveness and reliability of the proposed method.</div></div>","PeriodicalId":19586,"journal":{"name":"Optics Communications","volume":"607 ","pages":"Article 132963"},"PeriodicalIF":2.5,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146080069","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 : 2026-06-01Epub Date: 2026-01-13DOI: 10.1016/j.optcom.2026.132912
Songchan Cui , Hang Xu , Boyan Sun , Xiaohong Hu , Chang Niu , Hua Gao
Multimodal high-Q resonances are crucial for various advanced photonic devices. Surface lattice resonances (SLRs) represent a prominent approach for achieving high-Q resonances. However, their practical application is constrained by the stringent requirement for refractive-index-matching and the limited number of resonant modes. In this work, we propose a structure that supports multiple ultrahigh-Q guided-mode lattice resonances (GLRs) in an asymmetric environment by integrating a U-shaped split-ring resonator (U-SRR) array on a dielectric waveguide. By increasing the waveguide thickness, this platform not only readily achieves Q-factors exceeding 104, substantially surpassing conventional SLRs, but also increases the number of GLRs in groups. We theoretically elucidate the excitation mechanism of GLRs and the physical origin of their high Q-factors. Based on this mechanism, analytical formulas were derived to reliably predict the resonant wavelengths of these multiple-order GLRs. This work provides a straightforward method for achieving tunable, high-Q multimodal resonances, promising applications in advanced nanophotonic devices such as multimodal lasers and multiparameter sensors.
{"title":"Multimodal ultrahigh-Q lattice resonances supported by a U-shaped nanoarray integrated on a dielectric waveguide","authors":"Songchan Cui , Hang Xu , Boyan Sun , Xiaohong Hu , Chang Niu , Hua Gao","doi":"10.1016/j.optcom.2026.132912","DOIUrl":"10.1016/j.optcom.2026.132912","url":null,"abstract":"<div><div>Multimodal high-Q resonances are crucial for various advanced photonic devices. Surface lattice resonances (SLRs) represent a prominent approach for achieving high-Q resonances. However, their practical application is constrained by the stringent requirement for refractive-index-matching and the limited number of resonant modes. In this work, we propose a structure that supports multiple ultrahigh-Q guided-mode lattice resonances (GLRs) in an asymmetric environment by integrating a U-shaped split-ring resonator (U-SRR) array on a dielectric waveguide. By increasing the waveguide thickness, this platform not only readily achieves Q-factors exceeding 10<sup>4</sup>, substantially surpassing conventional SLRs, but also increases the number of GLRs in groups. We theoretically elucidate the excitation mechanism of GLRs and the physical origin of their high Q-factors. Based on this mechanism, analytical formulas were derived to reliably predict the resonant wavelengths of these multiple-order GLRs. This work provides a straightforward method for achieving tunable, high-Q multimodal resonances, promising applications in advanced nanophotonic devices such as multimodal lasers and multiparameter sensors.</div></div>","PeriodicalId":19586,"journal":{"name":"Optics Communications","volume":"606 ","pages":"Article 132912"},"PeriodicalIF":2.5,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146039187","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 : 2026-06-01Epub Date: 2026-01-14DOI: 10.1016/j.optcom.2026.132895
Haoxin Tian , Hanyu Zhan , David Voelz , Lejun Chen , Jizhou Lai
The Fried parameter and coherence radius are two fundamental measures that characterize the spatial resolution effects of atmospheric turbulence on optical propagation and imaging. Here, their calculations for spherical and plane waves in von Karman turbulence are theoretical developed that includes the effects of both nonzero inner scale and finite outer scale. The simple analytic expressions are also derived for making the results easy to use. Then the split-step wave optics simulations are performed for modeling the long-exposure point spread function and mutual coherence function through von Karman turbulence for comparison. The expressions and numerical results agree well throughout the weak to strong turbulent scattering regimes.
{"title":"Long-exposure fried parameter and coherence radius through von Karman atmospheric turbulence","authors":"Haoxin Tian , Hanyu Zhan , David Voelz , Lejun Chen , Jizhou Lai","doi":"10.1016/j.optcom.2026.132895","DOIUrl":"10.1016/j.optcom.2026.132895","url":null,"abstract":"<div><div>The Fried parameter and coherence radius are two fundamental measures that characterize the spatial resolution effects of atmospheric turbulence on optical propagation and imaging. Here, their calculations for spherical and plane waves in von Karman turbulence are theoretical developed that includes the effects of both nonzero inner scale and finite outer scale. The simple analytic expressions are also derived for making the results easy to use. Then the split-step wave optics simulations are performed for modeling the long-exposure point spread function and mutual coherence function through von Karman turbulence for comparison. The expressions and numerical results agree well throughout the weak to strong turbulent scattering regimes.</div></div>","PeriodicalId":19586,"journal":{"name":"Optics Communications","volume":"607 ","pages":"Article 132895"},"PeriodicalIF":2.5,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145996208","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 : 2026-06-01Epub Date: 2026-01-15DOI: 10.1016/j.optcom.2026.132910
Chon-Fai Kam
We investigate classical nonlinear optical analogues of excited-state quantum phase transitions (ESQPTs) within a squeezing-enhanced generalized Lipkin–Meshkov–Glick (LMG) model, focusing on polarization dynamics in optical fibers with tetragonal symmetry. Through systematic mapping of coupled-mode equations across crystal symmetries, we identify a novel non-conventional squeezing term that induces classical bifurcations—even without a linear rotor term. These bifurcations, analyzed in detail on the Poincaré sphere, correspond—via established semiclassical correspondence—to singularities in excited-state spectra characteristic of ESQPTs in the quantum LMG counterpart. Our findings highlight deep classical–quantum interplay in optical systems, providing a controllable room-temperature platform for simulating mean-field limits of many-body quantum criticality, with potential applications in quantum metrology and simulation. Full quantum spectral analysis is deferred to future work.
{"title":"Classical optical analogues of excited-state quantum phase transitions in a squeezing-enhanced generalized Lipkin–Meshkov–Glick model","authors":"Chon-Fai Kam","doi":"10.1016/j.optcom.2026.132910","DOIUrl":"10.1016/j.optcom.2026.132910","url":null,"abstract":"<div><div>We investigate classical nonlinear optical analogues of excited-state quantum phase transitions (ESQPTs) within a squeezing-enhanced generalized Lipkin–Meshkov–Glick (LMG) model, focusing on polarization dynamics in optical fibers with tetragonal symmetry. Through systematic mapping of coupled-mode equations across crystal symmetries, we identify a novel non-conventional squeezing term that induces classical bifurcations—even without a linear rotor term. These bifurcations, analyzed in detail on the Poincaré sphere, correspond—via established semiclassical correspondence—to singularities in excited-state spectra characteristic of ESQPTs in the quantum LMG counterpart. Our findings highlight deep classical–quantum interplay in optical systems, providing a controllable room-temperature platform for simulating mean-field limits of many-body quantum criticality, with potential applications in quantum metrology and simulation. Full quantum spectral analysis is deferred to future work.</div></div>","PeriodicalId":19586,"journal":{"name":"Optics Communications","volume":"606 ","pages":"Article 132910"},"PeriodicalIF":2.5,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145981667","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 : 2026-06-01Epub 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":"2026-06-01","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 : 2026-06-01Epub Date: 2026-01-22DOI: 10.1016/j.optcom.2026.132944
Xingyu Feng, Xinyan Wang, Yaowei Dai, Peng Gao, Cong Chen, Ying Zhang, Junfeng Fang, Hongfei Ma, Qiyao Wang, Hai Liu
The absorption or resonance wavelengths of certain gas molecules and biological macromolecules lie within the mid-infrared band, leading many researchers to focus on sensor design for this spectral region. However, current mid-infrared metasurface sensors typically possess only a single refractive index (RI) sensing parameter, with limited research dedicated to dual-parameter sensing of both RI and temperature. Furthermore, Quasi-Bound States in the Continuum (Q-BIC) can enhance light-matter interactions, thereby improving metasurface sensing performance. Therefore, this study proposes a high-performance, all-dielectric metasurface-based dual-parameter sensor operating in the mid-infrared band, leveraging Q-BIC. A simple perforation design breaks the structural symmetry, forming a magnetic dipole-dominated Q-BIC, which correlates the environmental RI with the material intrinsic RI, enabling exceptional dual-parameter sensing in the mid-infrared. For RI sensing, the maximum sensitivity achieved is 510.12 nm/RIU, the highest Figure of Merit (FoM) reaches 739.37 RIU−1, and the maximum Quality factor (Q-factor) is 11189.17. For temperature sensing, the maximum sensitivity is 0.30376 nm/°C, the highest FoM reaches 0.2217 °C-1, and the maximum Q-factor is 2496.54, both demonstrating excellent linear responses. Additionally, this structure can function as a polarization-dependent optical switch, with a transmission difference reaching 0.99448. This metasurface sensor holds significant application potential in fields such as security monitoring and biomedical detection.
{"title":"Realizing mid-infrared refractive index and temperature sensing of an all-dielectric metasurface based on Q-BIC","authors":"Xingyu Feng, Xinyan Wang, Yaowei Dai, Peng Gao, Cong Chen, Ying Zhang, Junfeng Fang, Hongfei Ma, Qiyao Wang, Hai Liu","doi":"10.1016/j.optcom.2026.132944","DOIUrl":"10.1016/j.optcom.2026.132944","url":null,"abstract":"<div><div>The absorption or resonance wavelengths of certain gas molecules and biological macromolecules lie within the mid-infrared band, leading many researchers to focus on sensor design for this spectral region. However, current mid-infrared metasurface sensors typically possess only a single refractive index (RI) sensing parameter, with limited research dedicated to dual-parameter sensing of both RI and temperature. Furthermore, Quasi-Bound States in the Continuum (Q-BIC) can enhance light-matter interactions, thereby improving metasurface sensing performance. Therefore, this study proposes a high-performance, all-dielectric metasurface-based dual-parameter sensor operating in the mid-infrared band, leveraging Q-BIC. A simple perforation design breaks the structural symmetry, forming a magnetic dipole-dominated Q-BIC, which correlates the environmental RI with the material intrinsic RI, enabling exceptional dual-parameter sensing in the mid-infrared. For RI sensing, the maximum sensitivity achieved is 510.12 nm/RIU, the highest Figure of Merit (FoM) reaches 739.37 RIU<sup>−1</sup>, and the maximum Quality factor (Q-factor) is 11189.17. For temperature sensing, the maximum sensitivity is 0.30376 nm/°C, the highest FoM reaches 0.2217 °C<sup>-1</sup>, and the maximum Q-factor is 2496.54, both demonstrating excellent linear responses. Additionally, this structure can function as a polarization-dependent optical switch, with a transmission difference reaching 0.99448. This metasurface sensor holds significant application potential in fields such as security monitoring and biomedical detection.</div></div>","PeriodicalId":19586,"journal":{"name":"Optics Communications","volume":"607 ","pages":"Article 132944"},"PeriodicalIF":2.5,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146080071","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}