Results in Optics最新文献

{"title":"Morphological and deposition temperature dependence of the nonlinear optical responses in nanostructures MoS2 thin films synthesized by the metal organic chemical vapor deposition","authors":"Y. Khattab,&nbsp;A.K. jazmati,&nbsp;A. Allaham","doi":"10.1016/j.rio.2026.101168","DOIUrl":"10.1016/j.rio.2026.101168","url":null,"abstract":"<div><div>The morphological and nonlinear optical properties of Molybdenum disulfide MoS₂ thin films, deposited by metal organic chemical vapor deposition at different temperatures, were studied. The morphology of the films, were determined by scanning electron microscopy and the structure was investigated by X-ray diffraction and Raman spectroscopy. Scanning electron microscopy images reveal the morphology of films consist of vertically oriented nanosheets. By increasing deposition temperature between 250 °C to 750 °C, the size of nanosheets increase from 100 nm to 350 nm and the thickness of the nanosheets are increased from 3 to 5 nm to 40-50 nm, while the vertical orientation still preserved. Optically: As the size of vertical nanosheets increased the bandgap values decreased from 2.25 eV to 2.05 eV, and the nonlinear response of thin films has increased. Surprisingly, under CW laser pumping, the mechanism of the nonlinear absorption has changed from positive to negative as the size and the thickness of nanosheets have increased. With high values of negative or positive nonlinear effective photo-thermal absorption coefficient absorption coefficient β_eff,th for vertical nanosheets at the order of 10³-10⁴ cm/W. While under nanoseconds pulses pumping, vertical nanosheets have reverse saturable absorption with nonlinear optical absorption coefficient β for vertical nanosheets at the order 10^-4 cm/W, and the transition between reverse saturable absorption to saturable absorption under CW resulting from thermal accumulation effect due to light trapping in these special nanostructures. Our results highlight the importance of vertical sheets and suggest their high potential for applications in optoelectronic devices.</div></div>","PeriodicalId":21151,"journal":{"name":"Results in Optics","volume":"25 ","pages":"Article 101168"},"PeriodicalIF":3.3,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149156058","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Deep learning-based S-parameter prediction of a progressively extended eight-port terahertz MIMO antenna for 6G and next-generation IoT","authors":"Abdelbasset Azzouz,&nbsp;Ahmed Alqurashi,&nbsp;Esam Y.O. Zafar,&nbsp;Z. Zakaria,&nbsp;A.J.A. Al-Gburi","doi":"10.1016/j.rio.2026.101171","DOIUrl":"10.1016/j.rio.2026.101171","url":null,"abstract":"<div><div>Terahertz (THz) antenna design for sixth-generation (6G) wireless systems is computationally intensive owing to the strong sensitivity of radiation performance to geometrical and material parameters. This paper proposes a deep-learning-assisted framework for the progressive design of a compact multiband THz antenna, evolving from a single-port radiator to an eight-port multiple-input multiple-output (MIMO) configuration. A deep neural network (DNN) is trained on 130,000 parametric samples to predict the real and imaginary parts of the reflection coefficient, replacing repetitive full-wave simulations. Stochastic Gradient Descent (SGD), RMSProp, and Adam optimizers are comparatively evaluated, with Adam yielding the best performance, achieving a mean squared error (MSE) of 0.003015 and a coefficient of determination (<span><math><msup><mrow><mi>R</mi></mrow><mrow><mn>2</mn></mrow></msup></math></span>) of 0.962736. The DNN-optimized antenna exhibits stable multiband resonance over the 0.3–0.8 THz frequency range. When progressively extended to an eight-port MIMO array, the design achieves a return loss better than −22.5 dB, low inter-element mutual coupling, an envelope correlation coefficient (ECC) below 0.0017, and a diversity gain (DG) of 10 dB. The proposed DNN-driven framework substantially reduces the need for repeated full-wave simulations and provides an efficient methodology for the design of compact THz MIMO antennas for future 6G wireless applications.</div></div>","PeriodicalId":21151,"journal":{"name":"Results in Optics","volume":"25 ","pages":"Article 101171"},"PeriodicalIF":3.3,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149201546","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Photocatalytic desulfurization of real fuel by the synthesis of CdO/g-C3N4 nanocomposite as an efficient catalyst","authors":"Amir Azizi,&nbsp;Minoo Shariati,&nbsp;Zahra Shahbazy,&nbsp;Pouria Alaei Roozbahani","doi":"10.1016/j.rio.2026.101162","DOIUrl":"10.1016/j.rio.2026.101162","url":null,"abstract":"<div><div>Photocatalytic oxidative desulfurization has emerged as a promising alternative to conventional hydrodesulfurization for producing ultra-low-sulfur fuels under mild operating conditions. In this study, a visible-light-responsive CdO/g-C₃N₄ heterojunction nanocomposite was successfully synthesized via a simple co-precipitation route and applied for the oxidative desulfurization of real fuel, providing a more practical evaluation than conventional model-fuel systems. Structural and physicochemical characterizations by XRD, FT-IR, FE-SEM, EDS, elemental mapping, BET, and UV–Vis diffuse reflectance spectroscopy confirmed the successful formation of the CdO/g-C₃N₄ heterojunction with enhanced visible-light absorption and favorable surface properties. The synergistic interaction between CdO and g-C₃N₄ effectively promoted charge separation and suppressed electron–hole recombination, resulting in improved photocatalytic performance. Under the optimized operating conditions, including a catalyst dosage of 0.025 g L⁻¹, an H₂O₂-to-fuel ratio of 2:1, an acetic acid-to-fuel ratio of 0.5:1, and 90 min of visible-light irradiation, the nanocomposite achieved a sulfur removal efficiency of 98.4%. Control experiments confirmed that sulfur removal originated predominantly from photocatalytic oxidation rather than adsorption or photolysis. The catalyst also exhibited excellent structural stability and reusability over five consecutive cycles with only negligible loss of activity. These findings demonstrate that the CdO/g-C₃N₄ nanocomposite is a promising visible-light-responsive photocatalyst for the oxidative desulfurization of real gas condensate under laboratory conditions. However, further studies on long-term stability and practical-scale application are required to evaluate its industrial potential.</div></div>","PeriodicalId":21151,"journal":{"name":"Results in Optics","volume":"25 ","pages":"Article 101162"},"PeriodicalIF":3.3,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149053688","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Machine learning-assisted optical thermometry with carbon dots: photophysical foundations and intelligent temperature sensing","authors":"Suleiman Ibrahim Mohammad,&nbsp;Asokan Vasudevan,&nbsp;O. Almomani,&nbsp;Parul Madan,&nbsp;Amit Kumar Upadhyay,&nbsp;Sumit Sharma,&nbsp;Faiz Mahmood,&nbsp;Noman Nazeer,&nbsp;Shakhboz Meylikulov,&nbsp;Hadi Bastani","doi":"10.1016/j.rio.2026.101150","DOIUrl":"10.1016/j.rio.2026.101150","url":null,"abstract":"<div><div>Carbon dots (CDs) have emerged as promising luminescent nanothermometers for optical thermometry owing to their tunable optical properties, low toxicity, environmental compatibility, and structural versatility. However, the intrinsic complexity of their emission mechanisms and the multidimensional nature of synthesis–structure–property relationships continue to hinder the rational development of high-performance temperature-sensing platforms. This review examines the rapidly evolving intersection of CD thermometry and machine learning (ML), with emphasis on how data-driven methodologies are transforming both materials design and thermal-signal interpretation. The fundamental photophysical origins of temperature-dependent luminescence are first analyzed, focusing on the interplay between structural heterogeneity, excited-state dynamics, and thermometric information encoding. Subsequently, machine-learning frameworks relevant to optical sensor development are discussed from the perspectives of descriptor engineering, predictive modeling, uncertainty assessment, and adaptive design. By synthesizing recent advances in ML-assisted CD research, this review identifies emerging design principles governing optical-property prediction, luminescence optimization, and multidimensional temperature sensing. Particular attention is given to the transition from empirical optimization toward predictive and increasingly autonomous thermometric systems. The analysis further highlights unresolved challenges related to mechanistic ambiguity, model transferability, reproducibility, standardization, and real-world deployment. Finally, a future roadmap is proposed in which physically informed ML, integrated data infrastructures, and closed-loop discovery frameworks converge to enable the next generation of intelligent CD thermometric technologies.</div></div>","PeriodicalId":21151,"journal":{"name":"Results in Optics","volume":"25 ","pages":"Article 101150"},"PeriodicalIF":3.3,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148949475","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of poly(3-hexylthiophene) morphology formation on third-order nonlinear optical under green continuous wave excitation","authors":"Nursaadah Ahmad Poad,&nbsp;Ganesan Krishnan,&nbsp;Fadhlina Che Ros,&nbsp;Nurul Syahirah Nasuha Sa'aya,&nbsp;Norhana Abdul Halim,&nbsp;Nor Azlian Abdul Manaf,&nbsp;Siti Zulaikha Ngah Demon","doi":"10.1016/j.rio.2026.101172","DOIUrl":"10.1016/j.rio.2026.101172","url":null,"abstract":"<div><div>Optically tunable devices can be realized through structural modifications of semiconducting polymers, which also moderate their inherent performance limitations. In this study, the susceptibility of poly(3-hexylthiophene) (P3HT) to degradation and morphological collapse is mitigated by synthesizing P3HT nanowires, which exhibited higher crystallinity than amorphous form. Highly ordered π-π stacking within the crystalline P3HT nanowires network is macroscopically manifested by a steep anomalous dispersion slope in its linear refractive index profile. Third-order nonlinear optical (NLO) arising from changes in P3HT morphology were measured at near-resonant, the 532 nm continuous wave excitation. Open- and closed-aperture <em>Z</em>-scan profiles of amorphous P3HT and P3HT nanowires demonstrate reverse saturable absorption and self-defocusing behaviours that are also contributed by photothermal lensing. The investigated configurations yielded effective third-order NLO susceptibilities ranging from 1.72 × 10⁻⁹ esu to 3.62 × 10⁻⁹ esu, within NLO benchmark of conventional functional polymer systems. Notably, extended electronic delocalization in self-assembled P3HT nanowires moderated excited-state absorption pathways, resulting in a concentration-dependent nonlinear optical response with an overall mean <span><math><msup><mi>χ</mi><mfenced><mn>3</mn></mfenced></msup></math></span> suppression of 16.9% ((2.39 ± 0.47) <span><math><mo>×</mo><msup><mn>10</mn><mrow><mo>−</mo><mn>9</mn></mrow></msup></math></span>esu for nanowires versus (2.88 ± 0.84) <span><math><mo>×</mo><msup><mn>10</mn><mrow><mo>−</mo><mn>9</mn></mrow></msup></math></span>esu for amorphous P3HT).The vulnerability of the highly crystalline P3HT nanowires to chemical aging under ambient conditions persisted, as shown by X-ray photoelectron spectroscopy analysis. Current study demonstrates that P3HT nanowires were capable of light–matter interactions however with limited efficacy in blocking long-term chemical oxidation or significantly enhancing NLO performance. Still, continued exploration of organic nanomaterials remains promising for the development of sustainable optical power-limiting devices and solid-state laser components.</div></div>","PeriodicalId":21151,"journal":{"name":"Results in Optics","volume":"25 ","pages":"Article 101172"},"PeriodicalIF":3.3,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149045649","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Comprehensive analysis of 6G optical NOMA waveforms using neural network-based detection for high-order QAM modulation","authors":"Arun Kumar,&nbsp;Venkatachalam Revathi,&nbsp;Nishant Gaur,&nbsp;Aziz Nanthaamornphong","doi":"10.1016/j.rio.2026.101159","DOIUrl":"10.1016/j.rio.2026.101159","url":null,"abstract":"<div><div>This paper presents a comprehensive investigation of sixth-generation (6G) optical non-orthogonal multiple access (NOMA) waveform performance using high-order quadrature amplitude modulation (QAM) schemes ranging from 64-QAM to 512-QAM, with emphasis on detection reliability and spectral efficiency under practical impairments. A unified evaluation framework is developed to systematically compare classical detectors, namely minimum mean square error (MMSE) and QR-decomposition with M-algorithm maximum likelihood detection (QRM-MLD), standalone deep learning models including convolutional neural networks (CNN) and recurrent neural networks (RNN), as well as hybrid architectures combining CNN-MMSE and the proposed RNN-MMSE. Simulation results demonstrate that increasing the modulation order substantially degrades bit error rate (BER) performance; conventional optical NOMA requires approximately 20–22 dB signal-to-noise ratio (SNR) to achieve a BER of <span><math><mrow><mn>1</mn><msup><mrow><mn>0</mn></mrow><mrow><mo>−</mo><mn>3</mn></mrow></msup></mrow></math></span> at 512-QAM. In contrast, the proposed hybrid RNN-MMSE detector reduces this requirement to approximately 12.5–13 dB, yielding an SNR gain of up to 9–10 dB. Furthermore, power spectral density (PSD) analysis confirms that the hybrid model significantly suppresses spectral leakage, with sidelobe levels reduced below −130 dB/Hz. These improvements stem from the joint exploitation of statistical signal estimation and data-driven sequential learning, which effectively handles nonlinear distortions and multi-user interference in optical channels. The proposed framework maintains a favorable trade-off between detection performance and computational complexity, demonstrating that hybrid deep learning-assisted detection constitutes a robust and scalable solution for high-data-rate, interference-limited 6G optical communication systems.</div></div>","PeriodicalId":21151,"journal":{"name":"Results in Optics","volume":"25 ","pages":"Article 101159"},"PeriodicalIF":3.3,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149045662","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Efficient synthesis of Gd-doped ZnWO₄@GO composite and investigation of luminescence properties","authors":"Sadegh Azadmehr,&nbsp;Sanaz Alamdari,&nbsp;Majid Jafar Tafreshi,&nbsp;Aliasghar Najafzadehkhoee,&nbsp;Jose J. Velázquez,&nbsp;Shiva Khani,&nbsp;Pejman Rezaei","doi":"10.1016/j.rio.2026.101163","DOIUrl":"10.1016/j.rio.2026.101163","url":null,"abstract":"<div><div>This work investigates the structural, multi-excitation luminescence, and alpha-induced scintillation properties of a Gd-doped zinc tungstate/graphene oxide (ZnWO₄/GO: Gd) ternary nanocomposite. Pristine ZnWO₄, GO, and the ZnWO₄/GO: Gd composite were synthesized via a facile co-precipitation route combined with a modified Hummers' method. Comprehensive characterizations using XRD, XPS, TEM, FE-SEM, EDS, and FTIR confirmed the formation of the monoclinic wolframite ZnWO₄ phase with predominantly spherical nanoparticles (average size ∼111 nm) uniformly anchored onto the 2D GO sheets. Under ultraviolet illumination and ion-beam bombardment (2.2 MeV protons and 5.5 MeV alpha), the composite exhibited broad blue emission centered at 460–465 nm. This emission enhancement and spectral modulation are attributed to the synergistic interplay between Gd³⁺-mediated defect engineering in the host matrix and accelerated interfacial charge extraction facilitated by the GO network. Under irradiation with a 9.8 kBq ²⁴¹Am alpha source, the ZnWO₄/GO: Gd composite achieved a net counting rate of 2518 ± 2.9 counts s⁻¹, representing an approximately 2.69-fold enhancement (∼169% increase) compared to the ZnWO₄:Gd reference (936 ± 1.8 counts s⁻¹) under identical detection geometries. Furthermore, the ternary composite demonstrated high linearity with respect to alpha-source activity and a fast scintillation response time of approximately 0.59 μs. These results demonstrate the strong potential of Gd-modified ZnWO₄/GO nanocomposites as cost-effective, scalable, and efficient phosphors for ionizing-radiation detection and optoelectronic sensing applications.</div></div>","PeriodicalId":21151,"journal":{"name":"Results in Optics","volume":"25 ","pages":"Article 101163"},"PeriodicalIF":3.3,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149155651","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Synthesis, characterization and low power Z-scan study of bandgap-engineered N, S-co-doped carbon quantum dots using lasers of different colors","authors":"Shaghayegh Khalilzadeh,&nbsp;Ehsan Koushki,&nbsp;Mohammad-Reza Zamani-Meymian","doi":"10.1016/j.rio.2026.101169","DOIUrl":"10.1016/j.rio.2026.101169","url":null,"abstract":"<div><div>The tailoring of electronic states in carbon-based nanostructures through heteroatom doping remains a critical frontier for advanced optoelectronic applications. In this work, N, S-co-doped carbon quantum dots (N, S-CQDs) were synthesized via a facile hydrothermal method, and their linear and thermos-optical (TO) properties were systematically compared with those of pristine CQDs (S1). Upon N, S-co-doping, an apparent discrepancy was observed: The Tauc plot revealed an intrinsic core bandgap widening (blue-shift), whereas the photoluminescence (PL) spectra and TO responses shifted toward longer wavelengths (red-shift). This behavior is elucidated by a model where doping simultaneously widens the core bandgap and introduces dense, lower-energy surface states within the forbidden zone, dominating the radiative recombination. TO properties were investigated using the <em>Z</em>-scan technique under continuous wave (CW) laser excitation at multiple wavelengths: violet (405 nm), green (532 nm), and red (650 nm). The experimental results revealed that sample S2 exhibits significantly enhanced nonlinear absorption coefficients (<span><math><mi>β</mi></math></span>) and nonlinear refractive indices (<span><math><msub><mi>n</mi><mn>2</mn></msub></math></span>) compared to S1, identifying a robust Reverse Saturable Absorption (RSA) and self-defocusing behavior. Notably, the TO response reached its maximum in the red region, where the excitation energy enters into resonance with the dopant-induced surface levels. These findings provide a comprehensive framework for bandgap engineering in CQDs and demonstrate their high efficacy as versatile materials for multi-wavelength optical limiting and nonlinear photonic devices.</div></div>","PeriodicalId":21151,"journal":{"name":"Results in Optics","volume":"25 ","pages":"Article 101169"},"PeriodicalIF":3.3,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149155656","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Achieving higher efficiency in solar panels using gold nanosphere arrays in structure of Grated CdS and advanced interfacial layers","authors":"S. Kianjo,&nbsp;A.S. Nooramin","doi":"10.1016/j.rio.2026.101140","DOIUrl":"10.1016/j.rio.2026.101140","url":null,"abstract":"<div><div>The global energy crisis and urgency of transitioning to clean, sustainable energy sources have spurred advancements in solar cell technologies. This work presents a high-efficiency polymer solar cell with the architecture ZnO/CdS/PTB7:PC71BM/Au(NPs)/ZnWO₄/Au. The key components include CdS (ETL), ZnWO₄(HTL), PTB7:PC71BM (polymer absorber layer), Au (back metal contact), and Au Nanoparticles (Au NPs). The structure leverages near-infrared (NIR) absorption (650–1100 nm) through gold nanoparticles, thereby enhancing the performance. CdS was chosen for its superior carrier mobility and conductivity, while ZnWO₄ provides high hole mobility. PTB7:PC71BM further contributes exceptional optical and electrical properties, achieving a power conversion efficiency (PCE) of 44.02%. This innovative architecture addresses NIR absorption limitations, achieving significant advancements in solar energy conversion efficiency. The optical and electrical performance of the proposed structure was investigated using 3D finite-difference time-domain (FDTD) method for electromagnetic simulation coupled with drift–diffusion modeling for carrier transport. This hybrid light-trapping architecture, combining grated CdS and double-layer Au nanoparticles with bimodal spacing, offers significant advantages including absorption enhancement in the NIR region (650–1100 nm), reduced recombination losses, and improved charge extraction. The novelty of this work lies in the synergistic integration of photonic grating modes with plasmonic effects using a double-layer Au NP configuration, achieving a theoretical power conversion efficiency of 44.02%, a substantial improvement over conventional structures.</div></div>","PeriodicalId":21151,"journal":{"name":"Results in Optics","volume":"25 ","pages":"Article 101140"},"PeriodicalIF":3.3,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148939889","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Machine learning-assisted hybrid graphene–MXene–WS₂ terahertz metasurface biosensor for highly sensitive label-free chikungunya virus detection","authors":"G. Arunachalam,&nbsp;A.R. Kalaiarasi,&nbsp;Giri.G. Hallur,&nbsp;V. Parthasarathy","doi":"10.1016/j.rio.2026.101149","DOIUrl":"10.1016/j.rio.2026.101149","url":null,"abstract":"<div><div>Chikungunya virus (CHIKV) remains a major mosquito-borne disease requiring rapid and label-free diagnostic technologies for early detection This study presents a terahertz (THz) metasurface biosensor comprising tungsten disulfide (WS₂) square resonators, MXene concentric rings, gold (Au) circular resonators, copper (Cu) structures, and a gate-tunable monolayer graphene layer on a SiO₂ substrate for numerical investigation of refractive-index sensing using values representative of healthy and CHIKV-related plasma and platelet samples. Finite element simulations in COMSOL Multiphysics were performed to optimize the graphene chemical potential, incident angle, circular resonator radius, and square resonator dimensions. The optimized sensor exhibits a resonance frequency of 0.355 THz with strong electric-field confinement, achieving a maximum numerically predicted refractive-index sensitivity of 907 GHz/RIU over the representative refractive-index range of 1.33–1.39 RIU. The device maintains stable spectral performance for incident angles from 0° to 80°. XGBoost regression models accurately predicted the transmission response for varying structural parameters, achieving R² &gt; 0.997 with low prediction errors. The present work represents a computational proof-of-concept demonstrating the feasibility of a THz metasurface for refractive-index sensing relevant to CHIKV detection. Experimental validation through device fabrication, biofunctionalization with CHIKV-specific recognition elements, and testing using clinical samples will be pursued in future studies to establish practical diagnostic performance.</div></div>","PeriodicalId":21151,"journal":{"name":"Results in Optics","volume":"25 ","pages":"Article 101149"},"PeriodicalIF":3.3,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148939890","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}