Photonics and Nanostructures-Fundamentals and Applications最新文献

{"title":"Polarization-selective dual-channel PCF-SPR sensor with orthogonal plasmonic interfaces for wide-range refractive index detection","authors":"Md. Jahid Hasan,&nbsp;Mahjabin Alam Mim,&nbsp;Nargis Sultana","doi":"10.1016/j.photonics.2026.101608","DOIUrl":"10.1016/j.photonics.2026.101608","url":null,"abstract":"<div><div>A dual-channel photonic crystal fiber surface plasmon resonance (PCF-SPR) refractive index sensor is proposed for polarization-selective analyte detection over two distinct RI regimes. The sensing architecture employs two orthogonally positioned plasmonic regions integrated with side-polished surfaces to strengthen the evanescent-field interaction between the guided core mode and the plasmonic/analyte interface. The design rationale is based on the tangential nature of surface plasmon excitation at the metal-dielectric boundary, allowing Channel-I (CH-I) and Channel-II (CH-II) to respond selectively to y- and x-polarized modes, respectively. Unlike conventional single-window or merely dual-polarization PCF-SPR/LSPR sensors, the proposed structure enables two independently optimized sensing channels for low-to-mid and high RI analytes. CH-I operates over the RI range of 1.24–1.43 and achieves a maximum wavelength sensitivity of 11,500 nm/RIU, maximum amplitude sensitivity of −1291.2 RIU⁻¹, figure of merit of 287.14 RIU⁻¹, optimized resolution of 8.70 × 10⁻⁶ RIU, and calibration coefficient of R² = 0.9617. CH-II operates over the higher RI range of 1.46–1.54 and demonstrates superior performance, with a maximum wavelength sensitivity of 26,000 nm/RIU, maximum amplitude sensitivity of −3526.65 RIU⁻¹, figure of merit of 1210.428 RIU⁻¹, optimized resolution of 1.00 × 10⁻⁶ RIU, and calibration coefficient of R² = 0.9993. These results confirm that orthogonal plasmonic placement combined with polarization-selective modal excitation can significantly improve RI detection capability while broadening the practical sensing applicability of PCF-SPR platforms.</div></div>","PeriodicalId":49699,"journal":{"name":"Photonics and Nanostructures-Fundamentals and Applications","volume":"72 ","pages":"Article 101608"},"PeriodicalIF":3.5,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148572969","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}

{"title":"A tunable dual-function terahertz metamaterial absorber based on vanadium dioxide and graphene","authors":"Yujie Yang,&nbsp;Yunfei Cui,&nbsp;Mao Wang,&nbsp;Zhengwei Xie,&nbsp;Mingyang Tian,&nbsp;Yijia Huang,&nbsp;Yarong Su,&nbsp;Jie Zheng,&nbsp;Mingjun Tang","doi":"10.1016/j.photonics.2026.101612","DOIUrl":"10.1016/j.photonics.2026.101612","url":null,"abstract":"<div><div>In this paper, a tunable dual-function terahertz absorber is proposed by integrating the phase-transition property of vanadium dioxide (VO₂) with the Fermi-level tunability of graphene. Here, the dual functionality specifically refers to broadband absorption switching over 3.0–4.25 THz, with the absorptance tunable from nearly 0 to nearly 98%, and narrowband-to-broadband mode conversion over 4.25–5.50 THz. Electromagnetic-field analyses indicate that the broadband absorption is associated with the Fabry–Pérot (FP) cavity resonance between the graphene and VO₂ layers, together with dipolar and higher-order multipolar resonances induced by localized surface plasmon resonance (LSPR) in graphene, whereas the narrowband absorption mainly originates from the LSPR in the graphene layer. Further investigations show that the tunable absorptance can be realized through the electrically tunable properties of graphene and the thermally tunable properties of vanadium dioxide. In addition, in the broadband mode, absorptance above 90% can be maintained for incident angles from 0° to 50°, and polarization insensitivity can be achieved under normal incidence. The proposed absorber provides both broadband switching and broadband–narrowband mode switching, showing potential for multifunctional terahertz dynamic devices.</div></div>","PeriodicalId":49699,"journal":{"name":"Photonics and Nanostructures-Fundamentals and Applications","volume":"72 ","pages":"Article 101612"},"PeriodicalIF":3.5,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148572968","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}

{"title":"Spatiotemporal optical differentiation and generation of spatiotemporal optical vortices using single-layer antireflection coatings","authors":"Artem I. Kashapov,&nbsp;Evgeni A. Bezus,&nbsp;Dmitry A. Bykov,&nbsp;Leonid L. Doskolovich","doi":"10.1016/j.photonics.2026.101593","DOIUrl":"10.1016/j.photonics.2026.101593","url":null,"abstract":"<div><div>We consider a spatiotemporal optical differentiator consisting of a single-layer antireflection coating that performs the optical computation of a differential operator corresponding to the sum of the partial derivatives of the incident pulse envelope with respect to time and a spatial coordinate. We demonstrate theoretically and numerically that such a differentiator makes it possible to generate an optical pulse possessing a spatiotemporal optical vortex, as well as to implement the edge detection operation in the spatiotemporal domain with high quality. The obtained results may find application in the development of analog optical computing and optical information processing systems.</div></div>","PeriodicalId":49699,"journal":{"name":"Photonics and Nanostructures-Fundamentals and Applications","volume":"72 ","pages":"Article 101593"},"PeriodicalIF":3.5,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148544310","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}

{"title":"Design of transparent multilayer films with infrared spectrally selective emissivity based on Bayes-GA","authors":"Gui Boheng,&nbsp;Liu Dongqing","doi":"10.1016/j.photonics.2026.101634","DOIUrl":"10.1016/j.photonics.2026.101634","url":null,"abstract":"<div><div>multispectral camouflage is important in modern military, particularly given the ongoing challenges in achieving synergistic control between high transmittance in visible range and spectrally selective emission in 3–14 μm. This paper proposes a practical inverse design strategy combining Bayesian optimization and genetic algorithms (Bayes-GA) for transparent multilayer films with infrared spectrally selective emissivity. The method operates in a four-dimensional space (material, number of layers, sequence, and thickness), automatically determining optimal hyperparameters as loss function weights. An optimized Ta₂O₅/ITO four-layer structure is designed, achieving a visible light transmittance of 72%, low emissivity in the atmospheric window (0.46 at 3–5 μm and 0.35 at 8–14 μm), and high emissivity (0.74) in the non-window band of 5–8 μm for radiative cooling. The structure exhibits insensitivity to variations in thickness (±10%) and incident angle (0°–60°), facilitating large-scale sputtering deposition fabrication. Furthermore, by coupling a color layer to the bottom layer, this film system enables multicolor visible light camouflage. This work provides an efficient and universal solution for the automated, high-degree-of-freedom design of multi-spectral compatible camouflage materials.</div></div>","PeriodicalId":49699,"journal":{"name":"Photonics and Nanostructures-Fundamentals and Applications","volume":"72 ","pages":"Article 101634"},"PeriodicalIF":3.5,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148843971","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}

{"title":"Blue laser micro-cavity based on porous-GaN DBR confinement layer and hetero-structure photonic crystal","authors":"Yuyi Cao,&nbsp;Lei Zheng,&nbsp;Yuan Huang,&nbsp;Qifa Liu","doi":"10.1016/j.photonics.2026.101610","DOIUrl":"10.1016/j.photonics.2026.101610","url":null,"abstract":"<div><div>GaN based lasers are pivotal in blue and visible semiconductor lasers. However, conventional GaN lasers face limitations in field confinement and modulation bandwidth. This study proposes a kind of blue-band photonic crystal laser cavity incorporating a porous-GaN/GaN distributed Bragg reflector (DBR) and a heterogeneous photonic crystal (PhC) structure. The porous-GaN DBR addresses challenges in epitaxial stress and low refractive index contrast by leveraging electrochemical etching to achieve high reflectivity (&gt;99.9%) with fewer layers (10 pairs) due to its tunable refractive index. The combination of hetero-structure PhC and porous-GaN DBR reduces resonant mode volume and in-plane losses while enhancing quality factor (Q&gt;9000), simultaneously improves optical confinement factor (Γ_act=9.1358%). Through systematic investigations, the optimized configuration demonstrates a 3-dB modulation bandwidth exceeding 46 GHz and energy consumption as low as 0.18 nJ/bit.</div></div>","PeriodicalId":49699,"journal":{"name":"Photonics and Nanostructures-Fundamentals and Applications","volume":"72 ","pages":"Article 101610"},"PeriodicalIF":3.5,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148642751","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}

{"title":"Tunable polarization-selective diffraction from plasmon-modified electromagnetically induced gratings in a double V-type configuration","authors":"Suleiman Ibrahim Mohammad,&nbsp;Mehulkumar B. Patel,&nbsp;Asokan Vasudevan,&nbsp;Malatesh Akkur,&nbsp;Basem Abu Zneid,&nbsp;Geetha Subramaniama,&nbsp;Nilufar Rajabova,&nbsp;Reya Sharma,&nbsp;Sanjeev Kumar,&nbsp;Ali Khalaf","doi":"10.1016/j.photonics.2026.101613","DOIUrl":"10.1016/j.photonics.2026.101613","url":null,"abstract":"<div><div>We study electromagnetically induced grating (EIG) in a double V-type atomic system driven by a standing-wave control field and interacting with circularly polarized probe light in the presence of a nearby plasmonic nanostructure. In free space, the system exhibits symmetric amplitude and phase modulations for left- and right-circular components, resulting in identical diffraction patterns with weak higher-order contributions. By increasing the intensity of the standing-wave field, phase modulation becomes dominant, leading to enhanced diffraction into higher orders. When the system is placed near a plasmonic nanostructure, symmetry between polarization components is broken due to plasmon-induced modifications of decay rates and susceptibility. This results in polarization-dependent grating formation and distinctly different diffraction behaviors. We further show that both emitter–plasmon separation and detuning provide effective control over the diffraction asymmetry, enabling tunable redistribution of optical energy among diffraction orders. The results demonstrate controllable anisotropic diffraction at the quantum–plasmonic interface with potential applications in polarization-selective light manipulation.</div></div>","PeriodicalId":49699,"journal":{"name":"Photonics and Nanostructures-Fundamentals and Applications","volume":"72 ","pages":"Article 101613"},"PeriodicalIF":3.5,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148642754","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}

{"title":"Reflection-mode dual-marker refractive-index sensor via dual fano resonances in a dielectric pillar lattice on a semi-open Ag/SiO2/Ag cavity","authors":"Thanh Son Pham,&nbsp;Minh Quy Tran,&nbsp;Xuan Bach Nguyen","doi":"10.1016/j.photonics.2026.101633","DOIUrl":"10.1016/j.photonics.2026.101633","url":null,"abstract":"<div><div>We numerically demonstrate a reflection-mode refractive-index sensor that combines a dielectric pillar lattice with a semi-open Ag/SiO<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>/Ag cavity to generate two spectrally separated resonant dips within one measured spectrum. The shorter-wavelength dip, denoted Mode S, is a high-<span><math><mi>Q</mi></math></span> analyte-sensitive resonance associated with a quasi-guided Bloch mode of the periodic lattice near the first-order Rayleigh anomaly. The longer-wavelength dip, denoted Mode R, is a cavity-related resonance that is comparatively less sensitive to analyte refractive-index variation and therefore serves as an internal spectral marker within the studied simulations. Because both resonances appear in the same reflection spectrum of a single unit cell, the simulated spectrum supports compact differential readout without a separate reference path. Full-wave FDTD simulations, supported by an effective cavity model, one-port temporal coupled-mode interpretation, and perturbative overlap arguments, are used to explain the dual-Fano line shape and the different superstrate sensitivities of the two modes. The same internal marker is also sensitive to interrogation angle, enabling the spectrum to carry both refractive-index information and alignment-diagnostic information. For the gas-phase design, the differential sensitivity reaches approximately 1167.9 nm/RIU, the dip-based quality factor of Mode S is about 2389.1, and the corresponding dip-based figure of merit is about <span><math><mrow><mn>2.27</mn><mo>×</mo><mn>1</mn><msup><mrow><mn>0</mn></mrow><mrow><mn>3</mn></mrow></msup></mrow></math></span> RIU⁻¹ in the idealized simulation. These dip-based metrics should be regarded as upper-bound simulated values until fabrication disorder, material loss uncertainty, and finite-beam effects are experimentally assessed. These results support a compact dual-marker near-infrared sensing architecture with reflection-mode operation under the present simulation evidence.</div></div>","PeriodicalId":49699,"journal":{"name":"Photonics and Nanostructures-Fundamentals and Applications","volume":"72 ","pages":"Article 101633"},"PeriodicalIF":3.5,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149004519","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}

{"title":"Low voltage nanophotonic resistive switch based on multi-tapered and engineered Cu-TiO2 structure on silicon with sensing capability","authors":"Rahul Dev Mishra,&nbsp;Suresh Kumar Pandey,&nbsp;Santosh Kumar,&nbsp;Ashutosh Kumar,&nbsp;Mukesh Kumar","doi":"10.1016/j.photonics.2026.101653","DOIUrl":"10.1016/j.photonics.2026.101653","url":null,"abstract":"<div><div>A resistive switch with optically readable and electrically writable capabilities is proposed in an engineered configuration consisting of multi-tapered and ring structures of Cu-TiO₂ on silicon. The device leverages the multifunctional properties of TiO₂ to enable low-voltage operation, a high extinction ratio (ER), and enhanced endurance with sensing capability. Incorporating multiple tapered regions with rings in a hybrid plasmonic waveguide enables areas with varying densities of conduction filaments in the light propagation direction. The tapered sections enhance, while the rings mitigate, light-filament interaction. The desired device functionalities are achieved with a combination of tapering and rings by modulating the interaction between a light-metal/oxygen vacancy filament. Well-defined hysteresis curves at 1550 nm prove optical readout of electrically written states in 10 nm thin TiO₂. An optical ER of 20 dB is reported for a 10 μm long device. Furthermore, it demonstrates an intrinsic stochastic property that lowers the set voltage in each set-reset sweep. In addition, the UV application on the device further lowers the set voltage. The lowered set voltage across multiple cycles preserves hysteresis and ensures high endurance. Additionally, the proposed device demonstrates CO₂ sensing based on the resistive switching phenomenon. Sensing capability, a high ER, and low voltage operation of the presented device pave the way for ultra-compact on-chip devices for optical switching and neuromorphic computing.</div></div>","PeriodicalId":49699,"journal":{"name":"Photonics and Nanostructures-Fundamentals and Applications","volume":"72 ","pages":"Article 101653"},"PeriodicalIF":3.5,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149153425","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}

{"title":"Electrically tunable metasurface unit cell for dual function on – off intensity switching and phase-delay with multilayer structure working at 525 nm","authors":"Huiyu Li,&nbsp;Yaqi Zhong,&nbsp;Huiyin Zhang,&nbsp;Li Liao,&nbsp;Guoqing Hu,&nbsp;Guangwei Chen,&nbsp;Zhehai Zhou","doi":"10.1016/j.photonics.2026.101614","DOIUrl":"10.1016/j.photonics.2026.101614","url":null,"abstract":"<div><div>An electrically tunable metasurface unit cell operating at 525 nm that enables dual-function optical modulation through on-off switching and continuous phase-delay control is discussed in this study. Tunable metasurfaces in the visible range are promising for compact wavefront-control devices, but achieving both high transmission contrast and a controllable phase response at low bias remains challenging. To address this gap, a multilayer unit cell architecture based on indium tin oxide (ITO), whose refractive index can be modulated by an applied bias voltage, is designed. The proposed structure enables simultaneous amplitude and phase tunability in the visible regime, particularly at low voltages. The structure further incorporates Al₂O₃ and MgF₂ dielectric layers, with PEDOT: PSS serving as the attaching layer, to enhance the tunable optical response and transmission. Numerical results show that through the adjustment of the bias voltage, the unit cell is enabled to achieve transmission modulation from approximately 60% to 0% while providing full 2π phase-delay coverage. In addition, owing to the symmetry inherent in the phase-delay structure, the unit cell demonstrates a polarization-insensitive property. This work elaborates on the design details of the electrically tunable metasurface unit cell at an incident wavelength of 525 nm, laying the groundwork for wavefront-control applications such as beam steering and shaping at low bias voltages. Furthermore, these results demonstrate the feasibility of achieving voltage-controlled optical on–off switching and phase-delay modulation with nanostructures, providing a fundamental basis for designing reconfigurable photonic devices in the visible spectrum.</div></div>","PeriodicalId":49699,"journal":{"name":"Photonics and Nanostructures-Fundamentals and Applications","volume":"72 ","pages":"Article 101614"},"PeriodicalIF":3.5,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148642753","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}

{"title":"Nanocomposites based on laser generated graphene-coated fluorescent superparamagnetic iron nanoparticles decorated with small Au and Se nanoparticles for the treatment of glioblastoma","authors":"Alexander V. Simakin,&nbsp;Ruslan M. Sarimov,&nbsp;Ilya V. Baimler,&nbsp;Ivan A. Popov,&nbsp;Oleg V. Uvarov,&nbsp;Elena D. Obraztsova,&nbsp;Sofia N. Bokova-Sirosh,&nbsp;Elena G. Varlamova,&nbsp;Egor A. Turovsky,&nbsp;Sergey V. Gudkov","doi":"10.1016/j.photonics.2026.101590","DOIUrl":"10.1016/j.photonics.2026.101590","url":null,"abstract":"<div><div>This paper describes a method for producing multifunctional Fe@C nanostructures decorated with Au and Se nanoparticles using laser ablation technology in liquid. Fe@C nanoparticles with dimensions of approximately 200 nm were synthesized by laser ablation of an iron target in isopropanol. TEM analysis of the particles revealed that the nanoparticles consist of a metallic iron core and a multilayer graphene shell. Au and Se nanoparticles with dimensions of 10–20 nm were deposited onto the graphene shell of the previously obtained Fe@C nanoparticles by creating critical conditions in a colloid, leading to intense particle aggregation. The effect of the resulting Fe@C nanocomposites decorated with Au and Se nanoparticles on glioblastoma cells was studied. The Fe@C/Au nanocomposite was shown to have no toxic effect on glioblastoma cells, while the Fe@C/Se nanocomposite caused cell death in approximately half of the cells. When an alternating magnetic field was applied, all Fe@C nanocomposites exerted a cytotoxic effect on glioblastoma cells, reducing cell viability by an additional 40%. The resulting cell death rate was approximately 90%. It should be noted that two independent anticancer mechanisms underlie this effect, selenium-induced apoptosis and magnetic hyperthermia.</div></div>","PeriodicalId":49699,"journal":{"name":"Photonics and Nanostructures-Fundamentals and Applications","volume":"72 ","pages":"Article 101590"},"PeriodicalIF":3.5,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148544313","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}