Pub Date : 2025-03-12DOI: 10.1016/j.photonics.2025.101379
Omar A.M. Abdelraouf , Ahmed Mousa , Mohamed Ragab
Metasurfaces are crucial in advancing flat optics and nanophotonics, offering unique advantages in creating vibrant structural colors and high-Q factor cavities. Multi-layer metasurfaces (MLMs) take this further by enhancing light-matter interactions inside the single meta-atom at the nanoscale. However, optimizing MLM designs is challenging due to the complex interplay of many parameters, making traditional simulation methods slow and inefficient. In this work, we introduce NanoPhotoNet, an advanced AI-powered design tool that leverages a hybrid deep neural network (DNN) combining convolutional neural networks (CNN) and Long Short-Term Memory (LSTM) models. NanoPhotoNet significantly accelerates the design process for MLMs, achieving over 98.3 % prediction accuracy and a 50,000x speed improvement compared to conventional techniques. This enables the creation of structural colors far beyond the standard RGB range, increasing the RGB gamut area up to 163 %. Additionally, NanoPhotoNet facilitates tunable color generation, extending the capabilities of MLMs to advanced applications like tunable color filters, nanolasers, and reconfigurable beam steering. This approach represents a transformative progress in metasurface design, unlocking new possibilities for high-performance, tunable nanophotonic devices.
{"title":"NanoPhotoNet: AI-enhanced design tool for reconfigurable and high-performance multi-layer metasurfaces","authors":"Omar A.M. Abdelraouf , Ahmed Mousa , Mohamed Ragab","doi":"10.1016/j.photonics.2025.101379","DOIUrl":"10.1016/j.photonics.2025.101379","url":null,"abstract":"<div><div>Metasurfaces are crucial in advancing flat optics and nanophotonics, offering unique advantages in creating vibrant structural colors and high-Q factor cavities. Multi-layer metasurfaces (MLMs) take this further by enhancing light-matter interactions inside the single meta-atom at the nanoscale. However, optimizing MLM designs is challenging due to the complex interplay of many parameters, making traditional simulation methods slow and inefficient. In this work, we introduce NanoPhotoNet, an advanced AI-powered design tool that leverages a hybrid deep neural network (DNN) combining convolutional neural networks (CNN) and Long Short-Term Memory (LSTM) models. NanoPhotoNet significantly accelerates the design process for MLMs, achieving over 98.3 % prediction accuracy and a 50,000x speed improvement compared to conventional techniques. This enables the creation of structural colors far beyond the standard RGB range, increasing the RGB gamut area up to 163 %. Additionally, NanoPhotoNet facilitates tunable color generation, extending the capabilities of MLMs to advanced applications like tunable color filters, nanolasers, and reconfigurable beam steering. This approach represents a transformative progress in metasurface design, unlocking new possibilities for high-performance, tunable nanophotonic devices.</div></div>","PeriodicalId":49699,"journal":{"name":"Photonics and Nanostructures-Fundamentals and Applications","volume":"64 ","pages":"Article 101379"},"PeriodicalIF":2.5,"publicationDate":"2025-03-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143637557","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}
High-efficiency and highly integrated optical switches in integrated photonic circuits have long been a pursuit for researchers. Due to the inherent limitations of silicon materials and fabrication processes, commonly used resonant or interferometric optical switches typically require tens to hundreds of micrometers of footprint to achieve desirable modulation efficiency. In response, we propose an optical switch structure filled with phase-change material (PCM) in a narrow slit, with tapered waveguides on curved sides coupling light in and out of the slit, enabling strong light-matter interaction. This structure consists of curved-side tapered coupling waveguides at both ends and a slit filled with GST (Ge2Sb2Te5) in the middle. By applying an external stimulus to induce a phase change in the GST, which exhibits significant differences in optical properties between its crystalline and amorphous states, substantial modulation efficiency can be achieved. Operating in the transverse electric mode within the band of 1500–1600 nm, this structure can achieve an extinction ratio (ER) of 34.08 dB and an insertion loss (IL) of 0.18 dB at 1550 nm, and this design can still achieve an ER over 27.26 dB and an IL less than 0.43 dB within a wavelength range of ± 50 nm, with an overall length of just 10 micrometers. The proposed structure offers high modulation efficiency and a low footprint, while also exhibiting high tolerance to fabrication errors, making it highly promising for future photonic communication systems.
{"title":"Compact hybrid waveguide optical switch with low loss and high extinction ratio based on Ge2Sb2Te5","authors":"Tong Jiang , Qipeng Zhan , Hao Ding , Zhixiang Huang , Li Ding","doi":"10.1016/j.photonics.2025.101368","DOIUrl":"10.1016/j.photonics.2025.101368","url":null,"abstract":"<div><div>High-efficiency and highly integrated optical switches in integrated photonic circuits have long been a pursuit for researchers. Due to the inherent limitations of silicon materials and fabrication processes, commonly used resonant or interferometric optical switches typically require tens to hundreds of micrometers of footprint to achieve desirable modulation efficiency. In response, we propose an optical switch structure filled with phase-change material (PCM) in a narrow slit, with tapered waveguides on curved sides coupling light in and out of the slit, enabling strong light-matter interaction. This structure consists of curved-side tapered coupling waveguides at both ends and a slit filled with GST (Ge<sub>2</sub>Sb<sub>2</sub>Te<sub>5</sub>) in the middle. By applying an external stimulus to induce a phase change in the GST, which exhibits significant differences in optical properties between its crystalline and amorphous states, substantial modulation efficiency can be achieved. Operating in the transverse electric mode within the band of 1500–1600 nm, this structure can achieve an extinction ratio (ER) of 34.08 dB and an insertion loss (IL) of 0.18 dB at 1550 nm, and this design can still achieve an ER over 27.26 dB and an IL less than 0.43 dB within a wavelength range of ± 50 nm, with an overall length of just 10 micrometers. The proposed structure offers high modulation efficiency and a low footprint, while also exhibiting high tolerance to fabrication errors, making it highly promising for future photonic communication systems.</div></div>","PeriodicalId":49699,"journal":{"name":"Photonics and Nanostructures-Fundamentals and Applications","volume":"64 ","pages":"Article 101368"},"PeriodicalIF":2.5,"publicationDate":"2025-03-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143592347","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 : 2025-03-01DOI: 10.1016/j.photonics.2025.101371
Md. Ferdous Rahman , Md. Mahin Tasdid , Mohammed M. Fadhali , Mukul Sharma , Mehdi Akermi
The limited photon absorption capacity of single-active-layer perovskite solar cells (PSCs) restricts their efficiency and scalability for future photovoltaic applications. This study introduces an innovative double perovskite active layer (DPAL) design, incorporating CsSnI3 and CsPbI3, along with a cadmium sulfide (CdS) electron transport layer (ETL), to overcome these challenges. Using the SCAPS-1D simulation tool, we demonstrate that this novel configuration significantly improves performance, achieving a power conversion efficiency (PCE) of 28.74 %, an open-circuit voltage (VOC) of 0.996 V, a short-circuit current density (JSC) of 34.94 mA/cm², and a fill factor (FF) of 82.61 %. These results surpass the efficiencies of single-active-layer designs, which reach 17.84 % for CsPbI3 and 24.08 % for CsSnI3. The study further explores the influence of active layer thickness, defect density, and interface defect densities on solar cell performance, along with the effects of doping concentration, series and shunt resistance, and temperature on PCE. This research highlights the potential of DPAL-based PSCs as a promising approach for achieving high-efficiency, stable, and cost-effective solar energy solutions.
{"title":"Unlocking Cesium based new double absorber perovskite solar cells with efficiency above 28 % for next generation solar cell","authors":"Md. Ferdous Rahman , Md. Mahin Tasdid , Mohammed M. Fadhali , Mukul Sharma , Mehdi Akermi","doi":"10.1016/j.photonics.2025.101371","DOIUrl":"10.1016/j.photonics.2025.101371","url":null,"abstract":"<div><div>The limited photon absorption capacity of single-active-layer perovskite solar cells (PSCs) restricts their efficiency and scalability for future photovoltaic applications. This study introduces an innovative double perovskite active layer (DPAL) design, incorporating CsSnI<sub>3</sub> and CsPbI<sub>3</sub>, along with a cadmium sulfide (CdS) electron transport layer (ETL), to overcome these challenges. Using the SCAPS-1D simulation tool, we demonstrate that this novel configuration significantly improves performance, achieving a power conversion efficiency (PCE) of 28.74 %, an open-circuit voltage (V<sub>OC</sub>) of 0.996 V, a short-circuit current density (J<sub>SC</sub>) of 34.94 mA/cm², and a fill factor (FF) of 82.61 %. These results surpass the efficiencies of single-active-layer designs, which reach 17.84 % for CsPbI<sub>3</sub> and 24.08 % for CsSnI<sub>3</sub>. The study further explores the influence of active layer thickness, defect density, and interface defect densities on solar cell performance, along with the effects of doping concentration, series and shunt resistance, and temperature on PCE. This research highlights the potential of DPAL-based PSCs as a promising approach for achieving high-efficiency, stable, and cost-effective solar energy solutions.</div></div>","PeriodicalId":49699,"journal":{"name":"Photonics and Nanostructures-Fundamentals and Applications","volume":"64 ","pages":"Article 101371"},"PeriodicalIF":2.5,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143578125","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 : 2025-02-24DOI: 10.1016/j.photonics.2025.101370
Junjiao Lu, Han Li, Xuejun Qiu, Hao Long, Jian Shen
This study presents a novel metamaterial structure utilizing graphene metamaterial for polarization control, resulting in a multi-window electromagnetically induced transparency (EIT)-like effect. The unit structure comprises double graphene square rings (DGSRs) and a parallel graphene strip (GS). By varying the angle of polarization of the incident light, the number of transparent windows can be switched among 0, 1, 2, and by manipulating the geometric parameters and Fermi level of the graphene structure, the amplitude and frequency of the transparent window can be dynamically adjusted. In addition, when the incident wave is obliquely incident, the metamaterial structure has good insensitivity to the incident angle (<60°). Furthermore, the potential applications of this metamaterial structure in slow light effect and refractive index sensing are also investigated, demonstrating its promising performance.
{"title":"Polarization controllable multi-window electromagnetically induced transparency-like in a graphene metamaterial","authors":"Junjiao Lu, Han Li, Xuejun Qiu, Hao Long, Jian Shen","doi":"10.1016/j.photonics.2025.101370","DOIUrl":"10.1016/j.photonics.2025.101370","url":null,"abstract":"<div><div>This study presents a novel metamaterial structure utilizing graphene metamaterial for polarization control, resulting in a multi-window electromagnetically induced transparency (EIT)-like effect. The unit structure comprises double graphene square rings (DGSRs) and a parallel graphene strip (GS). By varying the angle of polarization of the incident light, the number of transparent windows can be switched among 0, 1, 2, and by manipulating the geometric parameters and Fermi level of the graphene structure, the amplitude and frequency of the transparent window can be dynamically adjusted. In addition, when the incident wave is obliquely incident, the metamaterial structure has good insensitivity to the incident angle (<60°). Furthermore, the potential applications of this metamaterial structure in slow light effect and refractive index sensing are also investigated, demonstrating its promising performance.</div></div>","PeriodicalId":49699,"journal":{"name":"Photonics and Nanostructures-Fundamentals and Applications","volume":"64 ","pages":"Article 101370"},"PeriodicalIF":2.5,"publicationDate":"2025-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143519951","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 : 2025-02-20DOI: 10.1016/j.photonics.2025.101369
Ahmad Khanehzar, Naser Zamani, Ali Hatef
Phase change materials (PCMs) are attractive candidates for tunable devices due to their unique properties, such as high degree of scalability, thermal control, low power consumption, wide waveband operation, and the ability to switch between different optical phases. These properties can be enhanced by integrating PCMs with other materials, such as plasmonic nanoparticles. In this work, a core-shell nanostructure (Au@GSST) is proposed comprising a gold nanoparticle (AuNP) core coated with Ge2Sb2Se4Te1 (GSST), a PCM with high optical contrast, embedded in an aqueous medium. We demonstrate how the phase transition of GSST can be actively controlled by the light energy absorption of the Au@GSST. The integration of the Au core facilitates the phase change process of GSST due to its plasmonic effect, which leads to lower heat capacity and higher heat conductivity of the AuNP. These characteristics accelerate the GSST phase change process at a lower continuous wave (CW) laser intensity compared to a bare GSST nanoparticle. An induced photothermal process that includes heat transfer, the crystalline fraction, and the electric field enhancement of the Au@GSST, as functions of the laser wavelength and intensity is investigated. Our results show that through this process, the GSST shell can be tuned between fully amorphous, intermediate, and fully crystalline states. This phase transition leads to a substantial modification of the optical responses of the Au@GSST. The absorption, scattering and extinction cross-sections of the structure over a wide range of wavelengths before and after the GSST phase transition is studied. We focus on two specific wavelengths, 778 nm and 919 nm, which exhibit higher light absorption contrast in both the amorphous and crystalline phases of GSST. Such active tunning of Au@GSST without morphological variation can be utilized in reconfigurable nanophotonic devices, such as switches, modulators, and sensors.
{"title":"Tunable NIR nano-absorber based on photothermal response and thermoplasmonic modulation of Au@GSST core-shell nanoparticle","authors":"Ahmad Khanehzar, Naser Zamani, Ali Hatef","doi":"10.1016/j.photonics.2025.101369","DOIUrl":"10.1016/j.photonics.2025.101369","url":null,"abstract":"<div><div>Phase change materials (PCMs) are attractive candidates for tunable devices due to their unique properties, such as high degree of scalability, thermal control, low power consumption, wide waveband operation, and the ability to switch between different optical phases. These properties can be enhanced by integrating PCMs with other materials, such as plasmonic nanoparticles. In this work, a core-shell nanostructure (Au@GSST) is proposed comprising a gold nanoparticle (AuNP) core coated with Ge<sub>2</sub>Sb<sub>2</sub>Se<sub>4</sub>Te<sub>1</sub> (GSST), a PCM with high optical contrast, embedded in an aqueous medium. We demonstrate how the phase transition of GSST can be actively controlled by the light energy absorption of the Au@GSST. The integration of the Au core facilitates the phase change process of GSST due to its plasmonic effect, which leads to lower heat capacity and higher heat conductivity of the AuNP. These characteristics accelerate the GSST phase change process at a lower continuous wave (CW) laser intensity compared to a bare GSST nanoparticle. An induced photothermal process that includes heat transfer, the crystalline fraction, and the electric field enhancement of the Au@GSST, as functions of the laser wavelength and intensity is investigated. Our results show that through this process, the GSST shell can be tuned between fully amorphous, intermediate, and fully crystalline states. This phase transition leads to a substantial modification of the optical responses of the Au@GSST. The absorption, scattering and extinction cross-sections of the structure over a wide range of wavelengths before and after the GSST phase transition is studied. We focus on two specific wavelengths, 778 nm and 919 nm, which exhibit higher light absorption contrast in both the amorphous and crystalline phases of GSST. Such active tunning of Au@GSST without morphological variation can be utilized in reconfigurable nanophotonic devices, such as switches, modulators, and sensors.</div></div>","PeriodicalId":49699,"journal":{"name":"Photonics and Nanostructures-Fundamentals and Applications","volume":"64 ","pages":"Article 101369"},"PeriodicalIF":2.5,"publicationDate":"2025-02-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143480497","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 : 2025-02-01DOI: 10.1016/j.photonics.2025.101354
Zhensheng Wang , Yan Li , Haizhu Wang , Dengkui Wang , Jiao Wang , Minghui Lv , Lulu Gan , Shucun Zhao
In this paper, the InGaAs/GaAsP multiple quantum wells (MQWs) were successfully fabricated using metal-organic chemical vapor deposition (MOCVD) equipment, exhibiting the characteristics of a well-cluster composite (WCC) quantum structure. X-ray diffraction (XRD) tests indicated that the crystalline quality of the MQWs was high. Furthermore, photoluminescence (PL) tests revealed that the highly strained InGaAs/GaAsP quantum well structures could emit lasers simultaneously in the 950 nm and 1030 nm bands. This observation demonstrated that the double peaks observed in the quantum well photoluminescence were associated with indium-rich clusters (IRCs) generated by In-atom polarization, highlighting significant advantages for the development of new dual-wavelength lasers. This finding holds considerable importance for the advancement of novel monolithic quantum confined lasers that provide outputs in dual-wavelength and dual-polarization formats.
{"title":"Luminescence characterisation of composite quantum confinement structures of In0.29Ga0.71As well-cluster composite","authors":"Zhensheng Wang , Yan Li , Haizhu Wang , Dengkui Wang , Jiao Wang , Minghui Lv , Lulu Gan , Shucun Zhao","doi":"10.1016/j.photonics.2025.101354","DOIUrl":"10.1016/j.photonics.2025.101354","url":null,"abstract":"<div><div>In this paper, the InGaAs/GaAsP multiple quantum wells (MQWs) were successfully fabricated using metal-organic chemical vapor deposition (MOCVD) equipment, exhibiting the characteristics of a well-cluster composite (WCC) quantum structure. X-ray diffraction (XRD) tests indicated that the crystalline quality of the MQWs was high. Furthermore, photoluminescence (PL) tests revealed that the highly strained InGaAs/GaAsP quantum well structures could emit lasers simultaneously in the 950 nm and 1030 nm bands. This observation demonstrated that the double peaks observed in the quantum well photoluminescence were associated with indium-rich clusters (IRCs) generated by In-atom polarization, highlighting significant advantages for the development of new dual-wavelength lasers. This finding holds considerable importance for the advancement of novel monolithic quantum confined lasers that provide outputs in dual-wavelength and dual-polarization formats.</div></div>","PeriodicalId":49699,"journal":{"name":"Photonics and Nanostructures-Fundamentals and Applications","volume":"63 ","pages":"Article 101354"},"PeriodicalIF":2.5,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143167035","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}
A novel twin-core photonic crystal fiber (TC-PCF) sensor for alcohol detection has been introduced that specifically targets ethanol, propanol, butanol and pentanol. The sensor utilizes silica as a substrate material with circular air holes in the cladding region and operates between 2 µm and 3 µm range of wavelength. Simulations and evaluations are performed on COMSOL Multiphysics software interface. The twin core structure of this sensor contributes to its enhanced or high-precision sensitivity, and the TC-PCF is versatile, making it suitable for detecting four different types of alcohol. This sensor reveals exceptional wavelength sensitivities of 8383.168 nm/RIU, 13759.69 nm/RIU and 14554.26 nm/RIU for ethanol, propanol and butanol respectively for the fiber length of 1600 µm. The amplitude sensitivity for ethanol, propanol, and butanol are 2.95 RIU−1, 5.16 RIU−1 and 5.82 RIU−1 respectively, while the corresponding resolutions for ethanol, propanol and butanol are 119.2 × 10−7 RIU, 72.6 × 10−7 RIU and 68.7 × 10−7 RIU respectively. The figures of merit (FOM) are 29.50 RIU−1, 46.19 RIU−1 and 53.26 RIU−1 for ethanol, propanol and butanol respectively. The sensor offers high sensitivity, a compact design and ease of fabrication which offers significant advantages over traditional alcohol detection methods, making it highly suitable for future alcohol sensing applications.
{"title":"High-precision alcohol sensing using twin core photonic crystal fiber","authors":"Vikash Mourya , Sapana Yadav , Pooja Lohia , Adarsh Chandra Mishra , D.K. Dwivedi , Upendra Kulshrestha","doi":"10.1016/j.photonics.2024.101348","DOIUrl":"10.1016/j.photonics.2024.101348","url":null,"abstract":"<div><div>A novel twin-core photonic crystal fiber (TC-PCF) sensor for alcohol detection has been introduced that specifically targets ethanol, propanol, butanol and pentanol. The sensor utilizes silica as a substrate material with circular air holes in the cladding region and operates between 2 µm and 3 µm range of wavelength. Simulations and evaluations are performed on COMSOL Multiphysics software interface. The twin core structure of this sensor contributes to its enhanced or high-precision sensitivity, and the TC-PCF is versatile, making it suitable for detecting four different types of alcohol. This sensor reveals exceptional wavelength sensitivities of 8383.168 nm/RIU, 13759.69 nm/RIU and 14554.26 nm/RIU for ethanol, propanol and butanol respectively for the fiber length of 1600 µm. The amplitude sensitivity for ethanol, propanol, and butanol are 2.95 RIU<sup>−1</sup>, 5.16 RIU<sup>−1</sup> and 5.82 RIU<sup>−1</sup> respectively, while the corresponding resolutions for ethanol, propanol and butanol are 119.2 × 10<sup>−7</sup> RIU, 72.6 × 10<sup>−7</sup> RIU and 68.7 × 10<sup>−7</sup> RIU respectively. The figures of merit (FOM) are 29.50 RIU<sup>−1</sup>, 46.19 RIU<sup>−1</sup> and 53.26 RIU<sup>−1</sup> for ethanol, propanol and butanol respectively. The sensor offers high sensitivity, a compact design and ease of fabrication which offers significant advantages over traditional alcohol detection methods, making it highly suitable for future alcohol sensing applications.</div></div>","PeriodicalId":49699,"journal":{"name":"Photonics and Nanostructures-Fundamentals and Applications","volume":"63 ","pages":"Article 101348"},"PeriodicalIF":2.5,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143167894","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 : 2025-02-01DOI: 10.1016/j.photonics.2025.101353
Yuhan Ge , Zexu Liu , Xueyao Song , Jicheng Wang
The all-dielectric phase metasurface due to their low-loss characteristics can be used for efficient wavefront control in the optical visible range. In this paper, we construct and design an improved diatomic structure metasurface by using the joint regulation of geometric phase and propagation phase. Compared with single atomic structures, we introduce new degrees of freedom to flexibly and effectively control the phase and amplitude of the optical wavefront. We can joint geometric phase or propagation phase to arrange two kinds of supramolecular structures to sophisticatedly realize multifunctional modulations of on/off imaging distributions in the near field and different image displays in the far field. We believe that our research results can provide reference for multifunctional optical surfaces, dynamic optical control and optical information encryption.
{"title":"Multifunctional light field modulations of composite- phase-based diatomic metasurfaces","authors":"Yuhan Ge , Zexu Liu , Xueyao Song , Jicheng Wang","doi":"10.1016/j.photonics.2025.101353","DOIUrl":"10.1016/j.photonics.2025.101353","url":null,"abstract":"<div><div>The all-dielectric phase metasurface due to their low-loss characteristics can be used for efficient wavefront control in the optical visible range. In this paper, we construct and design an improved diatomic structure metasurface by using the joint regulation of geometric phase and propagation phase. Compared with single atomic structures, we introduce new degrees of freedom to flexibly and effectively control the phase and amplitude of the optical wavefront. We can joint geometric phase or propagation phase to arrange two kinds of supramolecular structures to sophisticatedly realize multifunctional modulations of on/off imaging distributions in the near field and different image displays in the far field. We believe that our research results can provide reference for multifunctional optical surfaces, dynamic optical control and optical information encryption.</div></div>","PeriodicalId":49699,"journal":{"name":"Photonics and Nanostructures-Fundamentals and Applications","volume":"63 ","pages":"Article 101353"},"PeriodicalIF":2.5,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143168033","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}
A novel method is proposed for improving electromagnetic radiation of antenna in two distant bands independently and consists of nanocomposite based electric, magnetic materials coating on radiator suitable for flexible antenna design. Coplanar waveguide (CPW) fed flexible radiator is designed and fabricated on thin cotton substrate, the radiating patch consists of heptagon ring, rigid structure and printed on surface of substrate. CPW antenna consists of a signal strip placed in between two rectangular ground plane at one side of the substrate and suitable for flexible conformal designs. The rigid strip radiates upper band signal due to its smaller dimension and heptagon strip generate lower band due to its longer structure. A nanocomposite based electric material Graphene Quantum Dots (GQDs) is coated on rigid radiating patch that enhance radiation of upper band and nanocomposite based magnetic material nickel (Ni) nanoparticles on heptagon ring patch to improve lower band characteristics of antenna. GQDs offer high conductivity and low loss tangent through sp²-hybridized carbon atoms, quantum confinement, and edge effects, making them ideal for transparent, flexible antennas with superior signal transmission. Ni has unpaired 3d-electrons that produce magnetic moments due to their spin and orbital angular momentum, enabling high conductivity, permeability, and frequency-dependent properties ideal for antenna. Nanocomposite coated antenna has gain, bandwidth enhancement of 96 % and 90 % respectively as compared to antenna without nanocomposite materials. The fabricated antenna attained 2.4/5.2/5.8 GHz WLAN, ISM, 5 G sub 6 GHz, 2.4/5.0 GHz Wi-Fi and 2.5/3.5/5.5 GHz WiMAX bands, suitable for practical wireless applications.
为改善天线在两个不同波段的独立电磁辐射，提出了一种新方法，该方法由基于纳米复合材料的电、磁材料涂层组成，适用于柔性天线设计。在薄棉基板上设计并制造了共面波导（CPW）馈电柔性辐射器，辐射贴片由七角环组成，具有刚性结构并印刷在基板表面。CPW 天线由放置在基板一侧两个矩形地平面之间的信号条组成，适用于柔性共形设计。刚性条带因其尺寸较小而辐射高频段信号，七边形条带因其结构较长而产生低频段信号。在刚性辐射贴片上涂覆基于纳米复合材料的电学材料石墨烯量子点（GQDs），可增强高频段辐射；在七角环形贴片上涂覆基于纳米复合材料的磁性材料镍（Ni）纳米颗粒，可改善天线的低频段特性。GQDs 通过sp²杂化碳原子、量子约束和边缘效应实现了高导电性和低损耗正切，是具有出色信号传输性能的透明柔性天线的理想材料。镍具有未配对的 3d 电子，它们的自旋和轨道角动量会产生磁矩，因此具有高导电性、磁导率和随频率变化的特性，是天线的理想材料。与不含纳米复合材料的天线相比，纳米复合材料涂层天线的增益和带宽分别提高了 96% 和 90%。所制造的天线达到了 2.4/5.2/5.8 GHz WLAN、ISM、5 G sub 6 GHz、2.4/5.0 GHz Wi-Fi 和 2.5/3.5/5.5 GHz WiMAX 频段，适合实际无线应用。
{"title":"Nanocomposite based electric and magnetic material enhancing electromagnetic characteristics of cotton substrate radiator","authors":"Abhilash S. Vasu , T.K. Sreeja , N.R. Lakshmi , Silpa Ajith Kumar","doi":"10.1016/j.photonics.2025.101367","DOIUrl":"10.1016/j.photonics.2025.101367","url":null,"abstract":"<div><div>A novel method is proposed for improving electromagnetic radiation of antenna in two distant bands independently and consists of nanocomposite based electric, magnetic materials coating on radiator suitable for flexible antenna design. Coplanar waveguide (CPW) fed flexible radiator is designed and fabricated on thin cotton substrate, the radiating patch consists of heptagon ring, rigid structure and printed on surface of substrate. CPW antenna consists of a signal strip placed in between two rectangular ground plane at one side of the substrate and suitable for flexible conformal designs. The rigid strip radiates upper band signal due to its smaller dimension and heptagon strip generate lower band due to its longer structure. A nanocomposite based electric material Graphene Quantum Dots (GQDs) is coated on rigid radiating patch that enhance radiation of upper band and nanocomposite based magnetic material nickel (Ni) nanoparticles on heptagon ring patch to improve lower band characteristics of antenna. GQDs offer high conductivity and low loss tangent through sp²-hybridized carbon atoms, quantum confinement, and edge effects, making them ideal for transparent, flexible antennas with superior signal transmission. Ni has unpaired 3d-electrons that produce magnetic moments due to their spin and orbital angular momentum, enabling high conductivity, permeability, and frequency-dependent properties ideal for antenna. Nanocomposite coated antenna has gain, bandwidth enhancement of 96 % and 90 % respectively as compared to antenna without nanocomposite materials. The fabricated antenna attained 2.4/5.2/5.8 GHz WLAN, ISM, 5 G sub 6 GHz, 2.4/5.0 GHz Wi-Fi and 2.5/3.5/5.5 GHz WiMAX bands, suitable for practical wireless applications.</div></div>","PeriodicalId":49699,"journal":{"name":"Photonics and Nanostructures-Fundamentals and Applications","volume":"63 ","pages":"Article 101367"},"PeriodicalIF":2.5,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143465434","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 : 2025-02-01DOI: 10.1016/j.photonics.2025.101358
Harith Ahmad , Kirubhashni Loganathan , Norazriena Yusoff , Mohamad Zamani Zulkifli
This study investigates the influence of deposition methods on the laser performance of Erbium-doped fiber lasers (EDFL). Two deposition methods, namely the drop-casting and airbrush-sprayed techniques, were employed. The reduced graphene oxide/magnesium oxide (rGO/MgO) composite applied using drop-casting on arc-shaped fiber shows a higher modulation depth of 3.27 %, surpassing the 2.12 % achieved by the airbrush-sprayed version. Both composites' structures ensure high thermal stability, allowing for continuous operation for 5 hours without performance degradation. The generation of mode-locking in the EDFL occurred when the incident light interacted with the rGO/MgO composite through the evanescent wave, reaching the threshold pump power of 389.69 mW. Integrating the saturable absorber (SA) in the cavity and adjusting the polarization controller (PC) enables stable pulse generation with a pulse duration of 0.91 ps for drop-casted arc-shape fiber and 1.32 ps for sprayed arc-shape fiber with a fundamental frequency of 18.10 MHz. The difference in modulation depth and laser performance is due to the condensed deposition achieved using drop-casting, resulting in improved interaction between light and matter and better saturable absorption properties. The results of this research provide a compelling alternative for ultrafast fiber lasers that are both compact and efficient, and they have the potential to be utilized in high-speed optical communication as well as medicinal imaging technologies.
{"title":"Studying the influence of deposition methods on ultrashort pulse generation","authors":"Harith Ahmad , Kirubhashni Loganathan , Norazriena Yusoff , Mohamad Zamani Zulkifli","doi":"10.1016/j.photonics.2025.101358","DOIUrl":"10.1016/j.photonics.2025.101358","url":null,"abstract":"<div><div>This study investigates the influence of deposition methods on the laser performance of Erbium-doped fiber lasers (EDFL). Two deposition methods, namely the drop-casting and airbrush-sprayed techniques, were employed. The reduced graphene oxide/magnesium oxide (rGO/MgO) composite applied using drop-casting on arc-shaped fiber shows a higher modulation depth of 3.27 %, surpassing the 2.12 % achieved by the airbrush-sprayed version. Both composites' structures ensure high thermal stability, allowing for continuous operation for 5 hours without performance degradation. The generation of mode-locking in the EDFL occurred when the incident light interacted with the rGO/MgO composite through the evanescent wave, reaching the threshold pump power of 389.69 mW. Integrating the saturable absorber (SA) in the cavity and adjusting the polarization controller (PC) enables stable pulse generation with a pulse duration of 0.91 ps for drop-casted arc-shape fiber and 1.32 ps for sprayed arc-shape fiber with a fundamental frequency of 18.10 MHz. The difference in modulation depth and laser performance is due to the condensed deposition achieved using drop-casting, resulting in improved interaction between light and matter and better saturable absorption properties. The results of this research provide a compelling alternative for ultrafast fiber lasers that are both compact and efficient, and they have the potential to be utilized in high-speed optical communication as well as medicinal imaging technologies.</div></div>","PeriodicalId":49699,"journal":{"name":"Photonics and Nanostructures-Fundamentals and Applications","volume":"63 ","pages":"Article 101358"},"PeriodicalIF":2.5,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143167030","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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