Pub Date : 2026-02-01DOI: 10.1016/j.rio.2026.100961
Sepehr Najafi, Mahdi Khaje, Abdollah Eslamimajd
Directional coupler (DC) and multimode interference (MMI) devices are widely used components in photonic integrated circuits (PICs). In this study, the structures of DC and MMI devices based on silicon nitride (Si3N4) are introduced and simulated, followed by a comprehensive comparison of these two beam splitters using the finite element method (FEM). Their performance and fabrication tolerances are evaluated, with the effects of manufacturing limitations, wavelength and polarization dependency being considered. Through numerical simulations, the impact of fabrication constraints on the robustness, efficiency, and practicality of these components is assessed. The results highlight the advantages and limitations of both devices under realistic fabrication conditions, providing valuable insights into their applicability for a range of optical applications.
{"title":"Directional coupler and multimode interference devices based on SiN: An approach to investigating fabrication tolerances","authors":"Sepehr Najafi, Mahdi Khaje, Abdollah Eslamimajd","doi":"10.1016/j.rio.2026.100961","DOIUrl":"10.1016/j.rio.2026.100961","url":null,"abstract":"<div><div>Directional coupler (DC) and multimode interference (MMI) devices are widely used components in photonic integrated circuits (PICs). In this study, the structures of DC and MMI devices based on silicon nitride (Si<sub>3</sub>N<sub>4</sub>) are introduced and simulated, followed by a comprehensive comparison of these two beam splitters using the finite element method (FEM). Their performance and fabrication tolerances are evaluated, with the effects of manufacturing limitations, wavelength and polarization dependency being considered. Through numerical simulations, the impact of fabrication constraints on the robustness, efficiency, and practicality of these components is assessed. The results highlight the advantages and limitations of both devices under realistic fabrication conditions, providing valuable insights into their applicability for a range of optical applications.</div></div>","PeriodicalId":21151,"journal":{"name":"Results in Optics","volume":"23 ","pages":"Article 100961"},"PeriodicalIF":3.0,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146079087","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-02-01DOI: 10.1016/j.rio.2026.100974
Muhammad Farid Ghazali , Hisham Mohamad , Muhammad Yusoff Mohd Nasir , Muhammad Aizzuddin Abdullah , Alarifi Hamzh , Muhammad Noor Adam Bin Kamaruzaman
Reliable monitoring of ground deformation during microtunneling is essential for safeguarding adjacent infrastructure and understanding soil–structure interaction under construction-induced loading. This study presents a performance evaluation of a Brillouin Optical Time Domain Analysis (BOTDA)-based distributed fibre optic strain sensing (DOFSS) inclinometer system applied to a microtunneling project beneath an active railway in Ipoh, Malaysia. Rather than introducing a new sensing methodology, the study focuses on assessing the practical performance, deployment behaviour, and limitations of a distributed fibre optic (FO) inclinometer under real construction conditions. The monitoring programme integrates laboratory calibration, field deployment, fibre integrity assessment, and numerical validation. Laboratory cantilever tests were conducted to verify strain transfer behaviour and calibrate strain-to-curvature and displacement reconstruction. Vertical and horizontal FO inclinometers were deployed to capture subsurface lateral deformation and near-surface settlement during pipe jacking operations. Field measurements identified clear deformation responses associated with the approach, passage, and departure of the tunneling machine. Fibre breakage events were analysed using Optical Time-Domain Reflectometry (OTDR), providing insight into installation-induced effects, grout stiffness, and casing rigidity on fibre survivability. Staged numerical simulations reproduced the observed deformation trends, supporting interpretation of field measurements. Overall, the results demonstrate that BOTDA-based distributed fibre optic inclinometers are effective for capturing spatially continuous trends of construction-induced ground deformation when installation strategy and mechanical coupling are appropriately controlled.
{"title":"Field performance and deployment challenges of a BOTDA-based distributed fibre optic inclinometer for microtunneling-induced ground deformation monitoring","authors":"Muhammad Farid Ghazali , Hisham Mohamad , Muhammad Yusoff Mohd Nasir , Muhammad Aizzuddin Abdullah , Alarifi Hamzh , Muhammad Noor Adam Bin Kamaruzaman","doi":"10.1016/j.rio.2026.100974","DOIUrl":"10.1016/j.rio.2026.100974","url":null,"abstract":"<div><div>Reliable monitoring of ground deformation during microtunneling is essential for safeguarding adjacent infrastructure and understanding soil–structure interaction under construction-induced loading. This study presents a performance evaluation of a Brillouin Optical Time Domain Analysis (BOTDA)-based distributed fibre optic strain sensing (DOFSS) inclinometer system applied to a microtunneling project beneath an active railway in Ipoh, Malaysia. Rather than introducing a new sensing methodology, the study focuses on assessing the practical performance, deployment behaviour, and limitations of a distributed fibre optic (FO) inclinometer under real construction conditions. The monitoring programme integrates laboratory calibration, field deployment, fibre integrity assessment, and numerical validation. Laboratory cantilever tests were conducted to verify strain transfer behaviour and calibrate strain-to-curvature and displacement reconstruction. Vertical and horizontal FO inclinometers were deployed to capture subsurface lateral deformation and near-surface settlement during pipe jacking operations. Field measurements identified clear deformation responses associated with the approach, passage, and departure of the tunneling machine. Fibre breakage events were analysed using Optical Time-Domain Reflectometry (OTDR), providing insight into installation-induced effects, grout stiffness, and casing rigidity on fibre survivability. Staged numerical simulations reproduced the observed deformation trends, supporting interpretation of field measurements. Overall, the results demonstrate that BOTDA-based distributed fibre optic inclinometers are effective for capturing spatially continuous trends of construction-induced ground deformation when installation strategy and mechanical coupling are appropriately controlled.</div></div>","PeriodicalId":21151,"journal":{"name":"Results in Optics","volume":"23 ","pages":"Article 100974"},"PeriodicalIF":3.0,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146079088","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-02-01DOI: 10.1016/j.rio.2026.100971
Juthika Alamgir Orpa, Al Nahid , Sunjida Sultana
Photonic integrated circuit has recently gained significant attention due to it’s diverse innovative applications. In this paper, we investigated a passive optical coupling in a waveguide via 3D FDTD simulation. It is based on a Si3N4 waveguide and a III-V binary compound test waveguide, with an amorphous Si optical bridge. It demonstrates FDTD simulations of optical field propagation and transmission. Here, the materials of the test waveguide are changed from GaAs to InAs to conduct a comparative study of binary semiconductor compounds with similar refractive index but different crystal structures. GaAs and InAs have different lattice constants, band gaps, electrical and optical properties. This waveguide, guides light using passive optical coupling. In this vertical coupling configuration light enters through Si3N4 waveguide and then amorphous Si and lastly the test waveguide. Here in the test waveguide, GaAs is used and then it is changed into InAs to study efficient coupling efficiency, optical power transmission, electric field distribution and photon transmission. In this waveguide, optical coupling occurs twice. The efficiency has been observed from the second coupling event. Also, the structural parameter has been changed, and the whole phenomenon has been studied for 1310 nm (O-band) to 1595 nm (L-band). The optical transmission ranges from 92% to 98%, with an observed coupling efficiency of 33%. We found that the studied waveguide could be employed to enable an efficient optical waveguide coupling to facilitate the transmission and change of light in photonic integrated circuit.
{"title":"FDTD investigation of optical integration between Si3N4 and III-V compound semiconductor based waveguide","authors":"Juthika Alamgir Orpa, Al Nahid , Sunjida Sultana","doi":"10.1016/j.rio.2026.100971","DOIUrl":"10.1016/j.rio.2026.100971","url":null,"abstract":"<div><div>Photonic integrated circuit has recently gained significant attention due to it’s diverse innovative applications. In this paper, we investigated a passive optical coupling in a waveguide via 3D FDTD simulation. It is based on a Si<sub>3</sub>N<sub>4</sub> waveguide and a III-V binary compound test waveguide, with an amorphous Si optical bridge. It demonstrates FDTD simulations of optical field propagation and transmission. Here, the materials of the test waveguide are changed from GaAs to InAs to conduct a comparative study of binary semiconductor compounds with similar refractive index but different crystal structures. GaAs and InAs have different lattice constants, band gaps, electrical and optical properties. This waveguide, guides light using passive optical coupling. In this vertical coupling configuration light enters through Si<sub>3</sub>N<sub>4</sub> waveguide and then amorphous Si and lastly the test waveguide. Here in the test waveguide, GaAs is used and then it is changed into InAs to study efficient coupling efficiency, optical power transmission, electric field distribution and photon transmission. In this waveguide, optical coupling occurs twice. The efficiency has been observed from the second coupling event. Also, the structural parameter has been changed, and the whole phenomenon has been studied for 1310 nm (O-band) to 1595 nm (L-band). The optical transmission ranges from 92% to 98%, with an observed coupling efficiency of 33%. We found that the studied waveguide could be employed to enable an efficient optical waveguide coupling to facilitate the transmission and change of light in photonic integrated circuit.</div></div>","PeriodicalId":21151,"journal":{"name":"Results in Optics","volume":"23 ","pages":"Article 100971"},"PeriodicalIF":3.0,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146079086","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-02-01DOI: 10.1016/j.rio.2025.100952
Kun Cao, Shuxiang Deng, Yang Xu, Keran Deng
This work reports a pioneering design of high-bandwidth, ultra-low-loss, and process-robust edge coupler optimized for 9-μm single-mode fibers. The architecture employs a bilayer waveguide structure comprising a silicon nitride top layer and a lithium niobate bottom layer. Through systematic geometric parameter optimization, the vertical mode matching efficiency is substantially enhanced, while a trident-shaped lithium niobate waveguide configuration is innovatively incorporated to fine-tune the lateral mode field distribution. Leveraging a two-stage inverse-tapered waveguide design, optical mode energy is efficiently transferred from the silica cladding to the lithium niobate ridge waveguide. Simulation results demonstrate that at 1550 nm, the coupler achieves an edge mode overlap loss of 0.05 dB and a TE-mode coupling loss of 0.16 dB per facet. Compared with current state-of-the-art processes, the achieved coupling efficiency exhibits exceptional performance benchmarks. Notably, it maintains exceptional transmission stability across a broad 300-nm(1400 nm-1700 nm) spectral bandwidth (Coupling loss < 0.3 dB/facet). In alignment tolerance characterization, vertical/lateral offsets of ± 2 μm result in insertion losses of 0.67 dB and 0.79 dB, respectively, underscoring its superior process robustness and engineering viability. Compared to current state-of-the-art designs, this work represents a notable advancement in reconciling process robustness with low-loss performance. This design provides a viable option for broadband optical communication devices.
{"title":"High-bandwidth and low-loss thin-film lithium niobate trident edge coupler","authors":"Kun Cao, Shuxiang Deng, Yang Xu, Keran Deng","doi":"10.1016/j.rio.2025.100952","DOIUrl":"10.1016/j.rio.2025.100952","url":null,"abstract":"<div><div>This work reports a pioneering design of high-bandwidth, ultra-low-loss, and process-robust edge coupler optimized for 9-μm single-mode fibers. The architecture employs a bilayer waveguide structure comprising a silicon nitride top layer and a lithium niobate bottom layer. Through systematic geometric parameter optimization, the vertical mode matching efficiency is substantially enhanced, while a trident-shaped lithium niobate waveguide configuration is innovatively incorporated to fine-tune the lateral mode field distribution. Leveraging a two-stage inverse-tapered waveguide design, optical mode energy is efficiently transferred from the silica cladding to the lithium niobate ridge waveguide. Simulation results demonstrate that at 1550 nm, the coupler achieves an edge mode overlap loss of 0.05 dB and a TE-mode coupling loss of 0.16 dB per facet. Compared with current state-of-the-art processes, the achieved coupling efficiency exhibits exceptional performance benchmarks. Notably, it maintains exceptional transmission stability across a broad 300-nm(1400 nm-1700 nm) spectral bandwidth (Coupling loss < 0.3 dB/facet). In alignment tolerance characterization, vertical/lateral offsets of ± 2 μm result in insertion losses of 0.67 dB and 0.79 dB, respectively, underscoring its superior process robustness and engineering viability. Compared to current state-of-the-art designs, this work represents a notable advancement in reconciling process robustness with low-loss performance. This design provides a viable option for broadband optical communication devices.</div></div>","PeriodicalId":21151,"journal":{"name":"Results in Optics","volume":"23 ","pages":"Article 100952"},"PeriodicalIF":3.0,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146079070","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-02-01DOI: 10.1016/j.rio.2026.100964
Arash Vaghef-Koodehi
This comprehensive theoretical study investigates a novel MXene-based side-illuminated Schottky photodetector (SIMS-PD) integrated on an InP waveguide platform for telecommunication wavelengths. Building on our previous work with graphene-based devices achieving responsivities up to 1.76 A/W, we propose a Ti3C2Tx MXene double-layer structure that theoretically demonstrates superior performance metrics. Through electromagnetic modeling using Lumerical MODE and COMSOL Multiphysics, we predict a responsivity of 2.31 A/W at 1.55 μm—representing a 31% improvement over trilayer graphene devices. The MXene structure exhibits ultra-low dark current (5 × 10−1⁶ A), exceptional detectivity (2.1 × 1013 Jones), and 42 GHz bandwidth capability. These enhanced properties arise from MXene’s unique combination of metallic conductivity (8,500 S/cm), tunable work function (4.1–4.8 eV), and strong optical absorption coefficient (3.8 × 105 cm−1). Comparative analysis reveals MXene’s advantages in terms of solution processability, environmental stability, and voltage tunability (Δμ = 0.8 eV) over graphene counterparts. The proposed device architecture features optimized field confinement at the MXene-InP interface with 85% modal overlap, achieving quantum efficiency of 0.69. This work establishes MXene as a promising alternative to graphene for next-generation integrated photodetectors, particularly for applications in optical communications, quantum technologies, and high-sensitivity sensing systems.
{"title":"High-Performance Ti3C2Tx MXene-InP Side-Illuminated Schottky Photodetector: Theoretical design and performance enhancement beyond Graphene-Based devices","authors":"Arash Vaghef-Koodehi","doi":"10.1016/j.rio.2026.100964","DOIUrl":"10.1016/j.rio.2026.100964","url":null,"abstract":"<div><div>This comprehensive theoretical study investigates a novel MXene-based side-illuminated Schottky photodetector (SIMS-PD) integrated on an InP waveguide platform for telecommunication wavelengths. Building on our previous work with graphene-based devices achieving responsivities up to 1.76 A/W, we propose a Ti<sub>3</sub>C<sub>2</sub>T<sub>x</sub> MXene double-layer structure that theoretically demonstrates superior performance metrics. Through electromagnetic modeling using Lumerical MODE and COMSOL Multiphysics, we predict a responsivity of 2.31 A/W at 1.55 μm—representing a 31% improvement over trilayer graphene devices. The MXene structure exhibits ultra-low dark current (5 × 10<sup>−</sup>1⁶ A), exceptional detectivity (2.1 × 1013 Jones), and 42 GHz bandwidth capability. These enhanced properties arise from MXene’s unique combination of metallic conductivity (8,500 S/cm), tunable work function (4.1–4.8 eV), and strong optical absorption coefficient (3.8 × 105 cm<sup>−</sup>1). Comparative analysis reveals MXene’s advantages in terms of solution processability, environmental stability, and voltage tunability (Δμ = 0.8 eV) over graphene counterparts. The proposed device architecture features optimized field confinement at the MXene-InP interface with 85% modal overlap, achieving quantum efficiency of 0.69. This work establishes MXene as a promising alternative to graphene for next-generation integrated photodetectors, particularly for applications in optical communications, quantum technologies, and high-sensitivity sensing systems.</div></div>","PeriodicalId":21151,"journal":{"name":"Results in Optics","volume":"23 ","pages":"Article 100964"},"PeriodicalIF":3.0,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146079085","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This paper presents a theoretical study of femtosecond-laser–induced ionization processes on diamond surfaces based on three analytical models: the multiphoton (MP) ionization model, the Ammosov–Delone–Krainov (ADK) tunneling model, and the Ivanov–Yudin (IY) model. The models were employed to analyze the dependence of plasma density on laser intensity, frequency ratio, and temporal evolution. The results reveal that the MP model is effective at low intensities and high frequencies, the ADK model is more accurate under strong-field conditions, and the IY model captures nonadiabatic and time-dependent effects, serving as an intermediate bridge between the two. Overall, a comprehensive understanding of laser–matter interactions requires a hybrid use of analytical models or their integration with advanced computational techniques, and the findings provide valuable insights for applications in micro- and nanoprocessing technologies, optical and quantum device fabrication, and biomedical sensing.
{"title":"Surface ionization of diamond by femtosecond laser pulses: A comparative study of analytical models","authors":"Zukhriddin Ruziev , Usman Sapaev , Husan Eshkuvatov , Rakhmatillo Karimov , Islom Egamberdiev , Madumar Musurmonov , Bekzod Rahmatov , Azamat Japakov , Shavkat Karshiboev , Khurshida Begmurodova , Rakhmat Turniyazov","doi":"10.1016/j.rio.2025.100942","DOIUrl":"10.1016/j.rio.2025.100942","url":null,"abstract":"<div><div>This paper presents a theoretical study of femtosecond-laser–induced ionization processes on diamond surfaces based on three analytical models: the multiphoton (MP) ionization model, the Ammosov–Delone–Krainov (ADK) tunneling model, and the Ivanov–Yudin (IY) model. The models were employed to analyze the dependence of plasma density on laser intensity, frequency ratio, and temporal evolution. The results reveal that the MP model is effective at low intensities and high frequencies, the ADK model is more accurate under strong-field conditions, and the IY model captures nonadiabatic and time-dependent effects, serving as an intermediate bridge between the two. Overall, a comprehensive understanding of laser–matter interactions requires a hybrid use of analytical models or their integration with advanced computational techniques, and the findings provide valuable insights for applications in micro- and nanoprocessing technologies, optical and quantum device fabrication, and biomedical sensing.</div></div>","PeriodicalId":21151,"journal":{"name":"Results in Optics","volume":"23 ","pages":"Article 100942"},"PeriodicalIF":3.0,"publicationDate":"2026-01-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146023850","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-16DOI: 10.1016/j.rio.2026.100962
Kris Bulmer, Jean-François Bisson, Alain Haché
Phase-change materials (PCMs) enable the modification of the polarization of reflected light over nanometer-scale distances. For an isotropic and homogeneous film deposited on planar substrates, this is only possible at oblique angles of incidence, and the greatest modulation occurs near the pseudo-Brewster angle, but at low reflectance. This tradeoff between polarization modulation and output intensity is a limiting factor for applications. In this paper, we explain why stronger polarization switching also tends to occur at low reflectance. We also show that for properly designed structures, switching between maximally separated, i.e. orthogonal, polarization states can occur with low losses. Finally, we compare the polarization switching capabilities of two different PCM materials on corrugated substrates at normal incidence and show that this simple design can achieve orthogonal polarization switching at high reflectance. For example, in the case of GST on a gold-coated grating at a wavelength λ of 1457 nm, near orthogonal switching is possible with a reflectance of around 50 %.
{"title":"High-efficiency polarization switching in phase-change-material films at normal incidence","authors":"Kris Bulmer, Jean-François Bisson, Alain Haché","doi":"10.1016/j.rio.2026.100962","DOIUrl":"10.1016/j.rio.2026.100962","url":null,"abstract":"<div><div>Phase-change materials (PCMs) enable the modification of the polarization of reflected light over nanometer-scale distances. For an isotropic and homogeneous film deposited on planar substrates, this is only possible at oblique angles of incidence, and the greatest modulation occurs near the pseudo-Brewster angle, but at low reflectance. This tradeoff between polarization modulation and output intensity is a limiting factor for applications. In this paper, we explain why stronger polarization switching also tends to occur at low reflectance. We also show that for properly designed structures, switching between maximally separated, i.e. orthogonal, polarization states can occur with low losses. Finally, we compare the polarization switching capabilities of two different PCM materials on corrugated substrates at normal incidence and show that this simple design can achieve orthogonal polarization switching at high reflectance. For example, in the case of GST on a gold-coated grating at a wavelength λ of 1457 nm, near orthogonal switching is possible with a reflectance of around 50 %.</div></div>","PeriodicalId":21151,"journal":{"name":"Results in Optics","volume":"23 ","pages":"Article 100962"},"PeriodicalIF":3.0,"publicationDate":"2026-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146023782","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-16DOI: 10.1016/j.rio.2026.100963
Bui Dinh Bao , Phan Nguyen Nhue , Duong Chi Dung , Vo Quang Sang , Nguyen Minh Hue , Mai Thi Kieu Trang , Nguyễn Văn Ba
Silver (Ag) mirror coatings on glass substrates are widely used in optics due to their high reflectance and low polarization of reflected light. However, poor adhesion between Ag and glass, together with limited oxidation resistance, significantly reduces coating durability and service life. This work focuses on optimizing the structure of silver mirrors through the selection of suitable adhesion-promoting and protective layers. Chromium (Cr), titanium (Ti), and nickel (Ni) were investigated as adhesion layers, given their compatibility with both BK7 glass substrates and silver films. Thin-film structures were designed and simulated using OptiLayer software and fabricated by high-vacuum thermal evaporation (base pressure <5 × 10−6 mbar, deposition rate ∼1,0 Å/s for Ag) in a Univex 400 system (Leybold, Germany). The optimized configuration, determined through simulation and subsequent experimental validation, was Ti (5 nm)/Ag (150 nm)/SiO2 (125 nm), which achieved reflectance above 95 % across the visible to near-infrared range (450–900 nm). Adhesion was evaluated according to ASTM D3359 and MIL-C-48479A standards, confirming strong film-substrate bonding. Experimental results were in good agreement with simulations, demonstrating the effectiveness of the multilayer design strategy for high-performance silver mirror coatings. To ensure measurement reliability, three identical samples were fabricated and characterized, and all reported reflectance values represent averaged results across this sample set.
{"title":"Optimization of silver mirror coatings on glass substrates by vacuum evaporation","authors":"Bui Dinh Bao , Phan Nguyen Nhue , Duong Chi Dung , Vo Quang Sang , Nguyen Minh Hue , Mai Thi Kieu Trang , Nguyễn Văn Ba","doi":"10.1016/j.rio.2026.100963","DOIUrl":"10.1016/j.rio.2026.100963","url":null,"abstract":"<div><div>Silver (Ag) mirror coatings on glass substrates are widely used in optics due to their high reflectance and low polarization of reflected light. However, poor adhesion between Ag and glass, together with limited oxidation resistance, significantly reduces coating durability and service life. This work focuses on optimizing the structure of silver mirrors through the selection of suitable adhesion-promoting and protective layers. Chromium (Cr), titanium (Ti), and nickel (Ni) were investigated as adhesion layers, given their compatibility with both BK7 glass substrates and silver films. Thin-film structures were designed and simulated using OptiLayer software and fabricated by high-vacuum thermal evaporation (base pressure <5 × 10<sup>−6</sup> mbar, deposition rate ∼1,0 Å/s for Ag) in a Univex 400 system (Leybold, Germany). The optimized configuration, determined through simulation and subsequent experimental validation, was Ti (5 nm)/Ag (150 nm)/SiO<sub>2</sub> (125 nm), which achieved reflectance above 95 % across the visible to near-infrared range (450–900 nm). Adhesion was evaluated according to ASTM <span><span>D3359</span><svg><path></path></svg></span> and MIL-C-48479A standards, confirming strong film-substrate bonding. Experimental results were in good agreement with simulations, demonstrating the effectiveness of the multilayer design strategy for high-performance silver mirror coatings. To ensure measurement reliability, three identical samples were fabricated and characterized, and all reported reflectance values represent averaged results across this sample set.</div></div>","PeriodicalId":21151,"journal":{"name":"Results in Optics","volume":"23 ","pages":"Article 100963"},"PeriodicalIF":3.0,"publicationDate":"2026-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146023783","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-15DOI: 10.1016/j.rio.2026.100968
Abdelbasset Azzouz , Rachid Bouhmidi , Mehr E. Munir , Muhammad Sheraz , Teong Chee Chuah , It Ee Lee
The rapid expansion of terahertz (THz) wireless technologies demands compact, high-performance antennas capable of operating over broad frequency ranges with minimal mutual coupling. In response, this work proposes a miniaturized dual-band multiple-input multiple-output (MIMO) antenna tailored for ultra-wideband (UWB) THz applications. To enhance impedance bandwidth and radiation efficiency, the design employs a Defected Ground Structure (DGS), which introduces deliberate discontinuities in the ground plane to suppress surface wave propagation. The proposed antenna exhibits a Mutual Envelope Gain (MEG) range between 0.35 and 0.50, a Total Active Reflection Coefficient (TARC) ranging from 0.5 to 2.5, and a Diversity Gain (DG) of 10, confirming its suitability for UWB MIMO performance metrics. Operating at 0.64 THz and 0.92 THz, the antenna achieves respective bandwidths of 0.12 THz and 0.26 THz, effectively covering the 0.5–1.05 THz range. Designed on a flexible polyimide substrate with a relative permittivity of 4.3 and loss tangent of 0.04, the antenna occupies a compact footprint of . The two-port MIMO configuration exhibits strong isolation, with an envelope correlation coefficient (ECC) of 0.006, indicating excellent diversity performance. Full-wave electromagnetic simulations performed using the High Frequency Structure Simulator (HFSS) confirm high impedance matching, with return losses of –56 dB and –30 dB, voltage standing wave ratios (VSWRs) close to 1, and peak gains of 19.56 dBi and 13.86 dBi. Compared to conventional THz antennas, the proposed design demonstrates a favorable balance of miniaturization, bandwidth, and MIMO isolation. Future work includes fabrication and experimental validation to confirm the simulation-based findings.
{"title":"Dual-band terahertz MIMO antenna using DGS for UWB applications","authors":"Abdelbasset Azzouz , Rachid Bouhmidi , Mehr E. Munir , Muhammad Sheraz , Teong Chee Chuah , It Ee Lee","doi":"10.1016/j.rio.2026.100968","DOIUrl":"10.1016/j.rio.2026.100968","url":null,"abstract":"<div><div>The rapid expansion of terahertz (THz) wireless technologies demands compact, high-performance antennas capable of operating over broad frequency ranges with minimal mutual coupling. In response, this work proposes a miniaturized dual-band multiple-input multiple-output (MIMO) antenna tailored for ultra-wideband (UWB) THz applications. To enhance impedance bandwidth and radiation efficiency, the design employs a Defected Ground Structure (DGS), which introduces deliberate discontinuities in the ground plane to suppress surface wave propagation. The proposed antenna exhibits a Mutual Envelope Gain (MEG) range between 0.35 and 0.50, a Total Active Reflection Coefficient (TARC) ranging from 0.5 to 2.5, and a Diversity Gain (DG) of 10, confirming its suitability for UWB MIMO performance metrics. Operating at 0.64 THz and 0.92 THz, the antenna achieves respective bandwidths of 0.12 THz and 0.26 THz, effectively covering the 0.5–1.05 THz range. Designed on a flexible polyimide substrate with a relative permittivity of 4.3 and loss tangent of 0.04, the antenna occupies a compact footprint of <span><math><mrow><mn>0</mn><mo>.</mo><mn>4</mn><mo>×</mo><mn>0</mn><mo>.</mo><mn>8</mn><mspace></mspace><msup><mrow><mtext>mm</mtext></mrow><mrow><mn>2</mn></mrow></msup></mrow></math></span>. The two-port MIMO configuration exhibits strong isolation, with an envelope correlation coefficient (ECC) of 0.006, indicating excellent diversity performance. Full-wave electromagnetic simulations performed using the High Frequency Structure Simulator (HFSS) confirm high impedance matching, with return losses of –56 dB and –30 dB, voltage standing wave ratios (VSWRs) close to 1, and peak gains of 19.56 dBi and 13.86 dBi. Compared to conventional THz antennas, the proposed design demonstrates a favorable balance of miniaturization, bandwidth, and MIMO isolation. Future work includes fabrication and experimental validation to confirm the simulation-based findings.</div></div>","PeriodicalId":21151,"journal":{"name":"Results in Optics","volume":"23 ","pages":"Article 100968"},"PeriodicalIF":3.0,"publicationDate":"2026-01-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145979973","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-13DOI: 10.1016/j.rio.2026.100967
Ajay Kumar Vyas, Krupa Purohit
The rapid advancements in technology and scientific research have led to an unprecedented demand for precise and reliable measurement systems. Traditional sensors, while highly effective in many domains, often face limitations in terms of sensitivity, accuracy, and environmental robustness. Unlike classical sensors, these devices offer unparalleled sensitivity and precision, enabling measurements of physical quantities such as magnetic fields, gravitational waves, and temperature with quantum-level accuracy. This study presents a comprehensive performance evaluation of various quantum sensing technologies for blood-based disease biomarker detection. Using simulation data from the Quantum Toolbox in Python (QuTiP), key performance metrics, including coherence time, signal-to-noise ratio, dynamic range, and entanglement, were analyzed across biomarkers.
Results indicate that Quantum Coherence sensors exhibit superior diagnostic potential due to their high coherence and signal fidelity, followed by Atomic Magnetometers and Nitrogen vacancy Centers, which offer a balance between sensitivity and practical deployment. While Quantum Dots demonstrated strengths in resolution and entanglement, they were limited by noise susceptibility. Superconducting Quantum Interference Devices, despite their established reliability, showed reduced performance in critical quantum metrics. Bridging the gap between laboratory validation and clinical deployment will require interdisciplinary collaboration, standardization, and large-scale clinical trials.
随着技术和科学研究的飞速发展，人们对精确可靠的测量系统产生了前所未有的需求。传统传感器虽然在许多领域都非常有效，但在灵敏度、精度和环境鲁棒性方面往往面临限制。与传统传感器不同，这些设备具有无与伦比的灵敏度和精度，能够以量子级精度测量磁场、引力波和温度等物理量。本研究对基于血液的疾病生物标志物检测的各种量子传感技术进行了综合性能评估。利用Python中的量子工具箱（Quantum Toolbox in Python, QuTiP）的模拟数据，分析了生物标记物的关键性能指标，包括相干时间、信噪比、动态范围和纠缠。结果表明，量子相干传感器由于其高相干性和信号保真度而具有优越的诊断潜力，其次是原子磁强计和氮空位中心，它们在灵敏度和实际部署之间提供了平衡。虽然量子点在分辨率和纠缠方面表现出优势，但它们受到噪声敏感性的限制。超导量子干涉器件，尽管其建立了可靠性，但在关键量子指标上表现出性能下降。弥合实验室验证和临床部署之间的差距需要跨学科合作、标准化和大规模临床试验。
{"title":"Blood Analysis using Quantum Sensor for different disease detection","authors":"Ajay Kumar Vyas, Krupa Purohit","doi":"10.1016/j.rio.2026.100967","DOIUrl":"10.1016/j.rio.2026.100967","url":null,"abstract":"<div><div>The rapid advancements in technology and scientific research have led to an unprecedented demand for precise and reliable measurement systems. Traditional sensors, while highly effective in many domains, often face limitations in terms of sensitivity, accuracy, and environmental robustness. Unlike classical sensors, these devices offer unparalleled sensitivity and precision, enabling measurements of physical quantities such as magnetic fields, gravitational waves, and temperature with quantum-level accuracy. This study presents a comprehensive performance evaluation of various quantum sensing technologies for blood-based disease biomarker detection. Using simulation data from the Quantum Toolbox in Python (QuTiP), key performance metrics, including coherence time, signal-to-noise ratio, dynamic range, and entanglement, were analyzed across biomarkers.</div><div>Results indicate that Quantum Coherence sensors exhibit superior diagnostic potential due to their high coherence and signal fidelity, followed by Atomic Magnetometers and Nitrogen vacancy Centers, which offer a balance between sensitivity and practical deployment. While Quantum Dots demonstrated strengths in resolution and entanglement, they were limited by noise susceptibility. Superconducting Quantum Interference Devices, despite their established reliability, showed reduced performance in critical quantum metrics. Bridging the gap between laboratory validation and clinical deployment will require interdisciplinary collaboration, standardization, and large-scale clinical trials.</div></div>","PeriodicalId":21151,"journal":{"name":"Results in Optics","volume":"23 ","pages":"Article 100967"},"PeriodicalIF":3.0,"publicationDate":"2026-01-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145979969","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
扫码关注我们
求助内容：
应助结果提醒方式：
京公网安备 11010802042870号