Pub Date : 2026-01-07DOI: 10.1016/j.optcom.2025.132860
Ke Li, Jinbin Gui, Mengxue Li, Haoyu Liu, Wengping Zhong
The Gerchberg-Saxton (GS) iterative algorithm is a classical method for phase retrieval but suffers from slow convergence and dependence on the initial phase. This paper proposes an optimized iterative algorithm based on image-plane phase momentum acceleration and amplitude feedback. Unlike weighted-type algorithms that primarily impose constraints on amplitude, the proposed algorithm constructs a momentum term utilizing historical phase information in the image plane. This term adjusts the input image-plane phase in each iteration. When the actual change trend of the image-plane phase aligns with the momentum direction, a significant acceleration effect is produced, effectively reducing the number of iterations and shrinking the size of the noise region. Numerical simulations demonstrate that the proposed method achieves superior reconstruction quality with smaller noise regions and exhibits stronger robustness to initial phase conditions. Optical experimental results are consistent with simulations, further validating the effectiveness of the proposed method.
{"title":"Optimized iterative algorithm for generating phase-only Fourier hologram based on phase momentum","authors":"Ke Li, Jinbin Gui, Mengxue Li, Haoyu Liu, Wengping Zhong","doi":"10.1016/j.optcom.2025.132860","DOIUrl":"10.1016/j.optcom.2025.132860","url":null,"abstract":"<div><div>The Gerchberg-Saxton (GS) iterative algorithm is a classical method for phase retrieval but suffers from slow convergence and dependence on the initial phase. This paper proposes an optimized iterative algorithm based on image-plane phase momentum acceleration and amplitude feedback. Unlike weighted-type algorithms that primarily impose constraints on amplitude, the proposed algorithm constructs a momentum term utilizing historical phase information in the image plane. This term adjusts the input image-plane phase in each iteration. When the actual change trend of the image-plane phase aligns with the momentum direction, a significant acceleration effect is produced, effectively reducing the number of iterations and shrinking the size of the noise region. Numerical simulations demonstrate that the proposed method achieves superior reconstruction quality with smaller noise regions and exhibits stronger robustness to initial phase conditions. Optical experimental results are consistent with simulations, further validating the effectiveness of the proposed method.</div></div>","PeriodicalId":19586,"journal":{"name":"Optics Communications","volume":"606 ","pages":"Article 132860"},"PeriodicalIF":2.5,"publicationDate":"2026-01-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145947894","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 : 2026-01-06DOI: 10.1016/j.optcom.2026.132874
M. Amraie , T. Fathollahi-Khalkhali , A. Aghamohammadi , E. Lotfi
This study numerically investigates methods to improve the coupling efficiency between planar photonic crystal (PC) lenses and ultra-slow light PC waveguides. The structures consist of aluminum oxide rod arrays in air, where modified and geometrically optimized W1 and W2 waveguides are combined with a linearly graded square lattice PC lens to achieve efficient coupling. A single frequency source excites various configurations of slow light waveguides, enabling a controlled evaluation of their coupling behavior. The results show that the optimized designs preserve high coupling efficiency , with the best configuration exhibiting a marked enhancement when even compared to standard photonic crystal waveguides. These findings demonstrate that properly engineered planar PC lenses can reliably inject light into ultra-slow light PC waveguides with minimal loss, supporting the development of compact photonic integrated circuits that require enhanced light–matter interactions and precise control of signal delay.
{"title":"Coupling performance of a planar lens to ultra slow-light photonic crystal waveguides: Simulation-based analysis and field distribution study","authors":"M. Amraie , T. Fathollahi-Khalkhali , A. Aghamohammadi , E. Lotfi","doi":"10.1016/j.optcom.2026.132874","DOIUrl":"10.1016/j.optcom.2026.132874","url":null,"abstract":"<div><div>This study numerically investigates methods to improve the coupling efficiency between planar photonic crystal (PC) lenses and ultra-slow light PC waveguides. The structures consist of aluminum oxide rod arrays in air, where modified and geometrically optimized W1 and W2 waveguides are combined with a linearly graded square lattice PC lens to achieve efficient coupling. A single frequency source excites various configurations of slow light waveguides, enabling a controlled evaluation of their coupling behavior. The results show that the optimized designs preserve high coupling efficiency <span><math><mrow><mn>11.75</mn><mspace></mspace><mi>d</mi><mi>B</mi></mrow></math></span>, with the best configuration exhibiting a marked enhancement when even compared to standard photonic crystal waveguides. These findings demonstrate that properly engineered planar PC lenses can reliably inject light into ultra-slow light PC waveguides with minimal loss, supporting the development of compact photonic integrated circuits that require enhanced light–matter interactions and precise control of signal delay.</div></div>","PeriodicalId":19586,"journal":{"name":"Optics Communications","volume":"605 ","pages":"Article 132874"},"PeriodicalIF":2.5,"publicationDate":"2026-01-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145980303","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 : 2026-01-06DOI: 10.1016/j.optcom.2026.132882
Meng Wu , Yongjia Yang , Daoxin Li , Lin Li , Biyi Wang , Wanli Zhao , Yong Jiang
The morphological characteristics of multi-core discrete filamentary damage induced by 355 nm ns laser irradiation in fused silica were investigated, along with the growth behavior and influencing mechanisms under multiple laser irradiation at varying energies. The results indicate that only low-energy lasers trigger repeated re-damage behavior, forming new damage zones of similar dimensions. The total filament length also increases substantially due to this re-damage behavior. During this process, the energy deposition location gradually shifts from the core zone to the front surface with successive irradiations, establishing a positive feedback loop of damage-plasma formation-enhanced damage. This ultimately inhibits bulk damage propagation, resulting in a surface-localized damage morphology. The results provide experimental evidence for understanding the damage mechanism in fused silica and the performance of optical components.
{"title":"Study on multi-core discrete filamentation in fused silica induced by ultraviolet laser","authors":"Meng Wu , Yongjia Yang , Daoxin Li , Lin Li , Biyi Wang , Wanli Zhao , Yong Jiang","doi":"10.1016/j.optcom.2026.132882","DOIUrl":"10.1016/j.optcom.2026.132882","url":null,"abstract":"<div><div>The morphological characteristics of multi-core discrete filamentary damage induced by 355 nm ns laser irradiation in fused silica were investigated, along with the growth behavior and influencing mechanisms under multiple laser irradiation at varying energies. The results indicate that only low-energy lasers trigger repeated re-damage behavior, forming new damage zones of similar dimensions. The total filament length also increases substantially due to this re-damage behavior. During this process, the energy deposition location gradually shifts from the core zone to the front surface with successive irradiations, establishing a positive feedback loop of damage-plasma formation-enhanced damage. This ultimately inhibits bulk damage propagation, resulting in a surface-localized damage morphology. The results provide experimental evidence for understanding the damage mechanism in fused silica and the performance of optical components.</div></div>","PeriodicalId":19586,"journal":{"name":"Optics Communications","volume":"605 ","pages":"Article 132882"},"PeriodicalIF":2.5,"publicationDate":"2026-01-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145980304","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}
Increasing global internet traffic may result capacity crunch in optical fiber networks, and the issue can be resolved by a low loss fiber with negligible latency. Here, we present a new strategy in antiresonant fiber design to transmit signal rapidly, reporting an extremely minimal loss and a tremendous bandwidth with a simpler structure. Interconnecting circular tubes within elliptical ones in cladding arrangement greatly enhance the negative and positive curvature layers, leading to a substantial improvement of fiber’s performance. It reveals the least confinement loss in the popular communication windows, as dB/km at and dB/km at , while offers the lowest loss level of dB/km at due to having additional tube layers. Besides, the reported fiber supports a 410 nm of broader bandwidth by sustaining a loss of dB/km covering most telecom band. Additionally, the surface scattering loss resulting from the thermodynamic fluctuations at the silica–air interface has been examined, revealing a minimal loss of dB/km at . Furthermore, the fiber reveals a minimal bending loss of dB/km at 4 cm and dB/km at 25 cm bend radius. Throughout the desired wavelength range; the fiber demonstrates modest bending loss even under significant bending conditions, and offers a highly effective single-mode response. Overall, the new cladding arrangement along with the superior performance of the reported fiber may have significant potential in optical communication systems.
{"title":"Extremely low loss and broad bandwidth in an interconnected nested tube antiresonant fiber","authors":"Kumary Sumi Rani Shaha , Munira Islam , Abdul Khaleque , Azra Sadia Sultana , Mst. Sumaya Akter , Rosni Sayed","doi":"10.1016/j.optcom.2026.132863","DOIUrl":"10.1016/j.optcom.2026.132863","url":null,"abstract":"<div><div>Increasing global internet traffic may result capacity crunch in optical fiber networks, and the issue can be resolved by a low loss fiber with negligible latency. Here, we present a new strategy in antiresonant fiber design to transmit signal rapidly, reporting an extremely minimal loss and a tremendous bandwidth with a simpler structure. Interconnecting circular tubes within elliptical ones in cladding arrangement greatly enhance the negative and positive curvature layers, leading to a substantial improvement of fiber’s performance. It reveals the least confinement loss in the popular communication windows, as <span><math><mrow><mn>2</mn><mo>×</mo><mn>1</mn><msup><mrow><mn>0</mn></mrow><mrow><mo>−</mo><mn>4</mn></mrow></msup></mrow></math></span> dB/km at <span><math><mrow><mn>1</mn><mo>.</mo><mn>55</mn><mspace></mspace><mi>μ</mi><mi>m</mi></mrow></math></span> and <span><math><mrow><mn>4</mn><mo>.</mo><mn>7</mn><mo>×</mo><mn>1</mn><msup><mrow><mn>0</mn></mrow><mrow><mo>−</mo><mn>4</mn></mrow></msup></mrow></math></span> dB/km at <span><math><mrow><mn>1</mn><mo>.</mo><mn>31</mn><mspace></mspace><mi>μ</mi><mi>m</mi></mrow></math></span>, while offers the lowest loss level of <span><math><mrow><mn>1</mn><mo>.</mo><mn>8</mn><mo>×</mo><mn>1</mn><msup><mrow><mn>0</mn></mrow><mrow><mo>−</mo><mn>4</mn></mrow></msup></mrow></math></span> dB/km at <span><math><mrow><mn>1</mn><mo>.</mo><mn>425</mn><mspace></mspace><mi>μ</mi><mi>m</mi></mrow></math></span> due to having additional tube layers. Besides, the reported fiber supports a 410 nm of broader bandwidth by sustaining a loss of <span><math><mo><</mo></math></span> <span><math><mrow><mn>2</mn><mo>×</mo><mn>1</mn><msup><mrow><mn>0</mn></mrow><mrow><mo>−</mo><mn>3</mn></mrow></msup></mrow></math></span> dB/km covering most telecom band. Additionally, the surface scattering loss resulting from the thermodynamic fluctuations at the silica–air interface has been examined, revealing a minimal loss of <span><math><mrow><mn>2</mn><mo>×</mo><mn>1</mn><msup><mrow><mn>0</mn></mrow><mrow><mo>−</mo><mn>2</mn></mrow></msup></mrow></math></span> dB/km at <span><math><mrow><mn>1</mn><mo>.</mo><mn>55</mn><mspace></mspace><mi>μ</mi><mi>m</mi></mrow></math></span>. Furthermore, the fiber reveals a minimal bending loss of <span><math><mrow><mn>1</mn><mo>×</mo><mn>1</mn><msup><mrow><mn>0</mn></mrow><mrow><mo>−</mo><mn>2</mn></mrow></msup></mrow></math></span> dB/km at 4 cm and <span><math><mrow><mn>8</mn><mo>×</mo><mn>1</mn><msup><mrow><mn>0</mn></mrow><mrow><mo>−</mo><mn>4</mn></mrow></msup></mrow></math></span> dB/km at 25 cm bend radius. Throughout the desired wavelength range; the fiber demonstrates modest bending loss even under significant bending conditions, and offers a highly effective single-mode response. Overall, the new cladding arrangement along with the superior performance of the reported fiber may have significant potential in optical communication systems.</div></div>","PeriodicalId":19586,"journal":{"name":"Optics Communications","volume":"605 ","pages":"Article 132863"},"PeriodicalIF":2.5,"publicationDate":"2026-01-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145929147","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 : 2026-01-06DOI: 10.1016/j.optcom.2026.132886
Chun-Yu Li , Yi-Yun Sie , Yu-Cheng Lin , Chen-En Tsai , Yu-Xiang Sun , Kuan-An Chen , Kuroda Hideki , Hung-Chen Kuo , Chih-Jung Chen
We propose a microlens array (MLA) structure to enhance the optical performance of quantum-dot color-conversion (QDCC) micro-LEDs for near-eye displays. The design integrates high-refractive-index microlenses with a low-refractive-index filler to reduce light divergence and increase forward brightness. The MLA/low-index filler configuration narrows the angular spread of scattered light, while the microlens curvature further collimates the emission. Simulation results indicate that, despite using a fully absorptive black bank to suppress optical crosstalk, increasing the microlens refractive index to 2.0 can still enhance the forward brightness of red, green, and blue sub-pixels by nearly fourfold. The MLA/low-index filler structure also improves angular color stability. As the structure is compatible with standard fabrication processes, it offers a practical solution for advanced near-eye micro-LED display integration.
{"title":"Enhancing optical performance of Micro-LEDs in near-eye displays via microlens-assisted light management","authors":"Chun-Yu Li , Yi-Yun Sie , Yu-Cheng Lin , Chen-En Tsai , Yu-Xiang Sun , Kuan-An Chen , Kuroda Hideki , Hung-Chen Kuo , Chih-Jung Chen","doi":"10.1016/j.optcom.2026.132886","DOIUrl":"10.1016/j.optcom.2026.132886","url":null,"abstract":"<div><div>We propose a microlens array (MLA) structure to enhance the optical performance of quantum-dot color-conversion (QDCC) micro-LEDs for near-eye displays. The design integrates high-refractive-index microlenses with a low-refractive-index filler to reduce light divergence and increase forward brightness. The MLA/low-index filler configuration narrows the angular spread of scattered light, while the microlens curvature further collimates the emission. Simulation results indicate that, despite using a fully absorptive black bank to suppress optical crosstalk, increasing the microlens refractive index to 2.0 can still enhance the forward brightness of red, green, and blue sub-pixels by nearly fourfold. The MLA/low-index filler structure also improves angular color stability. As the structure is compatible with standard fabrication processes, it offers a practical solution for advanced near-eye micro-LED display integration.</div></div>","PeriodicalId":19586,"journal":{"name":"Optics Communications","volume":"607 ","pages":"Article 132886"},"PeriodicalIF":2.5,"publicationDate":"2026-01-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146080070","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}
Electro-optic (EO) modulators based on lithium niobate (LiNbO3, LN) are indispensable components in high-speed optical communication systems, yet their high-frequency performance is significantly constrained by microwave (MW)-induced thermal effects. A thorough understanding of the underlying physical mechanisms is essential for interpreting device behavior and guiding the development of advanced modulator technologies. This study investigates thermal challenges in thin-film LN EO modulators under high-frequency MW excitation by establishing a comprehensive multi-physics model that couples electric, optical, thermal, and mechanical phenomena. The research offers detailed insights into how MW heating affects various physical fields within the device and ultimately influences optical transmission. Results demonstrate that the rise in localized temperature caused by MW heating modifies the refractive index distribution in LN waveguides via the thermo-optic effect, resulting in considerable nonlinear optical phase drift. Under high-frequency conditions, phase shifts induced by MW heating are markedly exacerbated, imposing a major constraint on the phase stability of modulators. This work provides a detailed explanation of fundamental principles of MW heating-induced phase shifts in modulators and explores the relationships among MW heating, temperature rise, phase shift, and their dependence. The findings establish an important theoretical foundation for the optimized design of next-generation high-performance EO modulators.
{"title":"Microwave thermal effects on the phase stability of lithium niobate electro-optic modulators","authors":"Fengze Yue, Xuehan Li, Yi Shen, Weijie Gao, Lanxiang Gao, Jing Chen","doi":"10.1016/j.optcom.2026.132884","DOIUrl":"10.1016/j.optcom.2026.132884","url":null,"abstract":"<div><div>Electro-optic (EO) modulators based on lithium niobate (LiNbO<sub>3</sub>, LN) are indispensable components in high-speed optical communication systems, yet their high-frequency performance is significantly constrained by microwave (MW)-induced thermal effects. A thorough understanding of the underlying physical mechanisms is essential for interpreting device behavior and guiding the development of advanced modulator technologies. This study investigates thermal challenges in thin-film LN EO modulators under high-frequency MW excitation by establishing a comprehensive multi-physics model that couples electric, optical, thermal, and mechanical phenomena. The research offers detailed insights into how MW heating affects various physical fields within the device and ultimately influences optical transmission. Results demonstrate that the rise in localized temperature caused by MW heating modifies the refractive index distribution in LN waveguides via the thermo-optic effect, resulting in considerable nonlinear optical phase drift. Under high-frequency conditions, phase shifts induced by MW heating are markedly exacerbated, imposing a major constraint on the phase stability of modulators. This work provides a detailed explanation of fundamental principles of MW heating-induced phase shifts in modulators and explores the relationships among MW heating, temperature rise, phase shift, and their dependence. The findings establish an important theoretical foundation for the optimized design of next-generation high-performance EO modulators.</div></div>","PeriodicalId":19586,"journal":{"name":"Optics Communications","volume":"605 ","pages":"Article 132884"},"PeriodicalIF":2.5,"publicationDate":"2026-01-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145929153","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 : 2026-01-05DOI: 10.1016/j.optcom.2026.132878
Longteng Qu , Ming Zhang , Tian Wang , Zhuoran Xu , Jian Wu , Ruzhi Wang
A flexible metamaterial absorber with a metal-dielectric-metal configuration is proposed for operation in the long-wave infrared (LWIR) region. The structure consists of a patterned Cr resonator array, an intermediate Ge/PDMS composite dielectric spacer, and a Ti substrate. Numerical simulations demonstrate that the absorber achieves an average absorption of 96.01 % across 8.01–13.96 μm, perfectly matching the full LWIR region and highlighting its strong application potential within the infrared atmospheric window (8–14 μm). The proposed absorber also exhibits excellent polarization independence and maintains high performance under large-angle incidence, ensuring robustness in complex natural environments. Systematic analyses of its structural parameters and applicability to alternative refractory materials verify the distinct advantage of the proposed absorber in achieving broadband absorption. The underlying absorption mechanism is clarified via electromagnetic field analysis at distinct resonance peaks, revealing that the broadband absorption arises from the synergistic coupling of multiple resonance modes. Collectively, these characteristics highlight the great potential of the proposed absorber for practical applications in LWIR remote sensing, environmental monitoring, and night vision imaging.
{"title":"Theoretical investigation on a flexible broadband metamaterial absorber in long-wave infrared band","authors":"Longteng Qu , Ming Zhang , Tian Wang , Zhuoran Xu , Jian Wu , Ruzhi Wang","doi":"10.1016/j.optcom.2026.132878","DOIUrl":"10.1016/j.optcom.2026.132878","url":null,"abstract":"<div><div>A flexible metamaterial absorber with a metal-dielectric-metal configuration is proposed for operation in the long-wave infrared (LWIR) region. The structure consists of a patterned Cr resonator array, an intermediate Ge/PDMS composite dielectric spacer, and a Ti substrate. Numerical simulations demonstrate that the absorber achieves an average absorption of 96.01 % across 8.01–13.96 μm, perfectly matching the full LWIR region and highlighting its strong application potential within the infrared atmospheric window (8–14 μm). The proposed absorber also exhibits excellent polarization independence and maintains high performance under large-angle incidence, ensuring robustness in complex natural environments. Systematic analyses of its structural parameters and applicability to alternative refractory materials verify the distinct advantage of the proposed absorber in achieving broadband absorption. The underlying absorption mechanism is clarified via electromagnetic field analysis at distinct resonance peaks, revealing that the broadband absorption arises from the synergistic coupling of multiple resonance modes. Collectively, these characteristics highlight the great potential of the proposed absorber for practical applications in LWIR remote sensing, environmental monitoring, and night vision imaging.</div></div>","PeriodicalId":19586,"journal":{"name":"Optics Communications","volume":"605 ","pages":"Article 132878"},"PeriodicalIF":2.5,"publicationDate":"2026-01-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145929151","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 : 2026-01-05DOI: 10.1016/j.optcom.2026.132879
Ziyue Wang , Hanfeng Xu , Yanli Zhang , Bing Wei , Xiaofeng Jin
An improved phase-generated carrier linear-fitting algorithm arctangent (PGC-LFA-Atan) method for signal demodulation of fiber interferometric sensors under small modulation depth is proposed and demonstrated. By utilizing the random sample consensus algorithm in the linear fitting process and subsequently using a nonlinear fitting curve, the distortion in the demodulated signal caused by modulation depth variation and carrier phase delay under a small modulation depth is greatly suppressed. Experimental results show that the total harmonic distortion of the demodulated signal is lower than 0.4 % and the signal-to-noise and distortion ratio is higher than 48 dB in the modulation range between 0.1 and 0.5 rad. The demodulated phase resolution is 1.78 × 10−5 rad/Hz1/2 @ 100 Hz and the dynamic range reaches 117.12 dB @ 100 Hz when the modulation depth is as low as 0.1 rad.
{"title":"PGC-LFA-Atan demodulation scheme for fiber interferometric sensing system under small modulation depth","authors":"Ziyue Wang , Hanfeng Xu , Yanli Zhang , Bing Wei , Xiaofeng Jin","doi":"10.1016/j.optcom.2026.132879","DOIUrl":"10.1016/j.optcom.2026.132879","url":null,"abstract":"<div><div>An improved phase-generated carrier linear-fitting algorithm arctangent (PGC-LFA-Atan) method for signal demodulation of fiber interferometric sensors under small modulation depth is proposed and demonstrated. By utilizing the random sample consensus algorithm in the linear fitting process and subsequently using a nonlinear fitting curve, the distortion in the demodulated signal caused by modulation depth variation and carrier phase delay under a small modulation depth is greatly suppressed. Experimental results show that the total harmonic distortion of the demodulated signal is lower than 0.4 % and the signal-to-noise and distortion ratio is higher than 48 dB in the modulation range between 0.1 and 0.5 rad. The demodulated phase resolution is 1.78 × 10<sup>−5</sup> rad/Hz<sup>1/2</sup> @ 100 Hz and the dynamic range reaches 117.12 dB @ 100 Hz when the modulation depth is as low as 0.1 rad.</div></div>","PeriodicalId":19586,"journal":{"name":"Optics Communications","volume":"605 ","pages":"Article 132879"},"PeriodicalIF":2.5,"publicationDate":"2026-01-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145929149","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 : 2026-01-05DOI: 10.1016/j.optcom.2026.132881
Xiaoyi Zhang , Wen Xing , Zhaohui Wang , Wenjing Yue , Song Gao
The rapid development of informatization and digitalization has brought certain risks and threats to user information security in modern society. So far, the encryption technology based on various algorithms has realized information protection in cyberspace. Metasurface provides a novel platform for the encryption of information in the optical dimension due to its flexible ability to manipulate various optical parameters. In this work, we propose and demonstrate a high-security optical encryption strategy that integrates metasurface optics with algorithmic encryption. Leveraging the metasurface's versatile capabilities in amplitude and polarization manipulation across three distinct wavelengths, we design a silicon nanopillar capable of orientation-angle-decoupled 3-bit intensity modulation. This functionality provides the foundation for encoding two encrypted carrier images and an encrypted pixel image, thereby establishing a physical-layer security mechanism. Building on this, a run-length encoding (RLE) scheme is ingeniously adopted to conceal both the encryption key and plaintext within the RLE sequences of the encoded images, introducing a second, algorithmic layer of security. This dual-layered encryption framework results in a nested optical protection scheme. In numerical simulations, the three designed binary images are reconstructed with high fidelity, enabling successful decryption of the embedded plaintext. Our approach provides a promising direction for future developments in metasurface-based optical encryption and information hiding.
{"title":"Single-sized silicon metasurface for three-channel and nested optical encryption","authors":"Xiaoyi Zhang , Wen Xing , Zhaohui Wang , Wenjing Yue , Song Gao","doi":"10.1016/j.optcom.2026.132881","DOIUrl":"10.1016/j.optcom.2026.132881","url":null,"abstract":"<div><div>The rapid development of informatization and digitalization has brought certain risks and threats to user information security in modern society. So far, the encryption technology based on various algorithms has realized information protection in cyberspace. Metasurface provides a novel platform for the encryption of information in the optical dimension due to its flexible ability to manipulate various optical parameters. In this work, we propose and demonstrate a high-security optical encryption strategy that integrates metasurface optics with algorithmic encryption. Leveraging the metasurface's versatile capabilities in amplitude and polarization manipulation across three distinct wavelengths, we design a silicon nanopillar capable of orientation-angle-decoupled 3-bit intensity modulation. This functionality provides the foundation for encoding two encrypted carrier images and an encrypted pixel image, thereby establishing a physical-layer security mechanism. Building on this, a run-length encoding (RLE) scheme is ingeniously adopted to conceal both the encryption key and plaintext within the RLE sequences of the encoded images, introducing a second, algorithmic layer of security. This dual-layered encryption framework results in a nested optical protection scheme. In numerical simulations, the three designed binary images are reconstructed with high fidelity, enabling successful decryption of the embedded plaintext. Our approach provides a promising direction for future developments in metasurface-based optical encryption and information hiding.</div></div>","PeriodicalId":19586,"journal":{"name":"Optics Communications","volume":"605 ","pages":"Article 132881"},"PeriodicalIF":2.5,"publicationDate":"2026-01-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145929148","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 : 2026-01-05DOI: 10.1016/j.optcom.2026.132873
Tianjiao Wu , Baoqun Li , Silun Du , Hanyu He , Tianshu Wang , Gang Deng
A compact all-fiber dual-wavelength Q-switched fiber laser(DW-QSFL)based on a high Q whispering-gallery-mode (WGM) microsphere resonator (MR) directly embedded into an erbium-doped fiber (EDF) ring cavity is proposed and experimentally demonstrated. Benefiting from the precise wavelength selectivity and strong thermo-optic response, the MR simultaneously functions as a comb filter and a passive Q-switching element. A novel Q-switching mechanism derived from dynamic thermo-optic effect is enabled by the MR, and the architecture is greatly simplified. A stable DW-QSFL is achieved at low pump threshold of 30.7 mW, featuring central wavelengths at 1558.22 nm and 1559.76 nm, with the side mode suppression ratio (SMSR) exceeding 58.2 dB. As the pump power increases from 30.7 mW to 57.8 mW, the pulse repetition rate rises from 21.8 kHz to 32.7 kHz, while the pulse width is compressed to 2.17 μs. The corresponding single-pulse energy and peak power reach 24.8 nJ and 11.4 mW, respectively. Furthermore, by adjusting the evanescent field overlap between the fiber taper and the MR, five distinct wavelength clusters with clear internal splitting and evolving pulse characteristics are obtained. The dual functionality of the MR in wavelength selection and pulse dynamic regulation is confirmed. The proposed integrated scheme effectively reduces system complexity and pump threshold, while improving spectral flexibility and operational robustness. This work provides a viable and novel pathway toward highly integrated multi-wavelength pulsed laser sources.
{"title":"Integrated dual-wavelength Q-switched fiber laser based on an embedded WGM microsphere resonator","authors":"Tianjiao Wu , Baoqun Li , Silun Du , Hanyu He , Tianshu Wang , Gang Deng","doi":"10.1016/j.optcom.2026.132873","DOIUrl":"10.1016/j.optcom.2026.132873","url":null,"abstract":"<div><div>A compact all-fiber dual-wavelength <em>Q</em>-switched fiber laser(DW-QSFL)based on a high <em>Q</em> whispering-gallery-mode (WGM) microsphere resonator (MR) directly embedded into an erbium-doped fiber (EDF) ring cavity is proposed and experimentally demonstrated. Benefiting from the precise wavelength selectivity and strong thermo-optic response, the MR simultaneously functions as a comb filter and a passive <em>Q</em>-switching element. A novel <em>Q</em>-switching mechanism derived from dynamic thermo-optic effect is enabled by the MR, and the architecture is greatly simplified. A stable DW-QSFL is achieved at low pump threshold of 30.7 mW, featuring central wavelengths at 1558.22 nm and 1559.76 nm, with the side mode suppression ratio (SMSR) exceeding 58.2 dB. As the pump power increases from 30.7 mW to 57.8 mW, the pulse repetition rate rises from 21.8 kHz to 32.7 kHz, while the pulse width is compressed to 2.17 μs. The corresponding single-pulse energy and peak power reach 24.8 nJ and 11.4 mW, respectively. Furthermore, by adjusting the evanescent field overlap between the fiber taper and the MR, five distinct wavelength clusters with clear internal splitting and evolving pulse characteristics are obtained. The dual functionality of the MR in wavelength selection and pulse dynamic regulation is confirmed. The proposed integrated scheme effectively reduces system complexity and pump threshold, while improving spectral flexibility and operational robustness. This work provides a viable and novel pathway toward highly integrated multi-wavelength pulsed laser sources.</div></div>","PeriodicalId":19586,"journal":{"name":"Optics Communications","volume":"605 ","pages":"Article 132873"},"PeriodicalIF":2.5,"publicationDate":"2026-01-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145929154","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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