The IoT in PV systems monitors the performance, fault diagnostics, predicts its performance, and improves the accuracy of the monitoring compared to the previous ones because of the continuous connectivity between sensing, communication, and processing tiers. This paper will provide a detailed literature review of IoT-supported solar PV systems with respect to their architecture and real-time monitoring systems that enable effective system operation and reliability. Different IoT based architectures are discussed such as the cloud architecture, edge architecture, and the fog computing architecture whereby each has their own unique roles in data acquisition, transmission, and analytics. Additionally, the paper examines the efficiency optimization methods, including adaptive maximum power point tracking, AI-driven data analytics, predictive maintenance, and intelligent cleaning technologies. The fact that these are complex features that have been integrated shows that the IoT can be used to make traditional PV systems smart enough to turn them into self-optimizing energy infrastructure. Lastly, the paper defines the important research opportunities and future directions, including the necessity to have scalable, secure, and interoperable IoT systems to enable next-generation sustainable energy systems.
{"title":"IoT-enabled solar PV systems: real-time monitoring and efficiency optimization","authors":"Geetam Shukla , Akash Kumar Shukla , K.N. Shukla , Shishir Dixit","doi":"10.1016/j.rio.2025.100949","DOIUrl":"10.1016/j.rio.2025.100949","url":null,"abstract":"<div><div>The IoT in PV systems monitors the performance, fault diagnostics, predicts its performance, and improves the accuracy of the monitoring compared to the previous ones because of the continuous connectivity between sensing, communication, and processing tiers. This paper will provide a detailed literature review of IoT-supported solar PV systems with respect to their architecture and real-time monitoring systems that enable effective system operation and reliability. Different IoT based architectures are discussed such as the cloud architecture, edge architecture, and the fog computing architecture whereby each has their own unique roles in data acquisition, transmission, and analytics. Additionally, the paper examines the efficiency optimization methods, including adaptive maximum power point tracking, AI-driven data analytics, predictive maintenance, and intelligent cleaning technologies. The fact that these are complex features that have been integrated shows that the IoT can be used to make traditional PV systems smart enough to turn them into self-optimizing energy infrastructure. Lastly, the paper defines the important research opportunities and future directions, including the necessity to have scalable, secure, and interoperable IoT systems to enable next-generation sustainable energy systems.</div></div>","PeriodicalId":21151,"journal":{"name":"Results in Optics","volume":"22 ","pages":"Article 100949"},"PeriodicalIF":3.0,"publicationDate":"2025-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145797925","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}
In this paper, an ideal highly sensitive THz biological sensor based on a polarization-insensitive graphene absorber with three bands is designed and optimized. The concept of a polarization-insensitive sensor involves a ring of graphene and eight symmetrical ring resonators. Finite element modeling reveals that the developed absorber may be fine-tuned for a sensing capacity and an absorption efficiency of over 99.8 %. At frequencies of 3.769 THz, 5.888 THz, and 9.453 THz, respectively, three distinct narrow absorption peaks with efficiencies of 98.6 %, 99.2 %, and 99.8 % are produced as a result of field confinement induced by graphene surface plasmon resonances. This study delineates our sensitive refractive index sensor, including circular micro ring resonator and multiple graphene rings. A periodic design consisting of a center ring and eight peripheral rings that rotate π/4 rad produces a three-band absorber arrangement independent of wave polarization. Moreover, it has been demonstrated that modifying the graphene layer’s chemical potential may change the resonance frequencies while improving absorber performance. A maximum sensitivity of 3045 GHz/RIU, a Q-factor of 26.01, and a figure-of-merit of 9.18 RIU−1 are achieved by the proposed refractive index sensor with an analyte thickness of 2.3 μm. The suggested THz RI sensor offers an identical response for TE and TM polarizations because of its rotational symmetry. The performance of RI sensors is assessed using two biological samples: breast cancer and healthy breast cells. The findings unequivocally demonstrate the THz sensor’s possible biological applications. Achieving high absorption and sensitivity is the main feature of this paper.
{"title":"Highly sensitive multi-mode tunable THz graphene-based refractive index biosensor","authors":"Ehsan Veisi , Mahmood Seifouri , Mina Amirmazlaghani , Fatemeh Geran Gharakhili , Saeed Olyaee","doi":"10.1016/j.rio.2025.100948","DOIUrl":"10.1016/j.rio.2025.100948","url":null,"abstract":"<div><div>In this paper, an ideal highly sensitive THz biological sensor based on a polarization-insensitive graphene absorber with three bands is designed and optimized. The concept of a polarization-insensitive sensor involves a ring of graphene and eight symmetrical ring resonators. Finite element modeling reveals that the developed absorber may be fine-tuned for a sensing capacity and an absorption efficiency of over 99.8 %. At frequencies of 3.769 THz, 5.888 THz, and 9.453 THz, respectively, three distinct narrow absorption peaks with efficiencies of 98.6 %, 99.2 %, and 99.8 % are produced as a result of field confinement induced by graphene surface plasmon resonances. This study delineates our sensitive refractive index sensor, including circular micro ring resonator and multiple graphene rings. A periodic design consisting of a center ring and eight peripheral rings that rotate π/4 rad produces a three-band absorber arrangement independent of wave polarization. Moreover, it has been demonstrated that modifying the graphene layer’s chemical potential may change the resonance frequencies while improving absorber performance. A maximum sensitivity of 3045 GHz/RIU, a Q-factor of 26.01, and a figure-of-merit of 9.18 RIU<sup>−1</sup> are achieved by the proposed refractive index sensor with an analyte thickness of 2.3 μm. The suggested THz RI sensor offers an identical response for TE and TM polarizations because of its rotational symmetry. The performance of RI sensors is assessed using two biological samples: breast cancer and healthy breast cells. The findings unequivocally demonstrate the THz sensor’s possible biological applications. Achieving high absorption and sensitivity is the main feature of this paper.</div></div>","PeriodicalId":21151,"journal":{"name":"Results in Optics","volume":"22 ","pages":"Article 100948"},"PeriodicalIF":3.0,"publicationDate":"2025-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145797943","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 : 2025-12-14DOI: 10.1016/j.rio.2025.100951
Marwa Salem , Mostafa M. Salah , Ahmed Shaker , Mohamed Abouelatta , Kawther A. Al-Dhlan , Mohammad T. Alshammari , Tariq S. Almurayziq , Muhammad Tauseef Qureshi , Mohamed Mousa
The primary objective of next-generation solar cell technologies is to achieve higher power conversion efficiency (PCE) while maintaining long-term operational stability. Among the promising approaches to meet this demand, tandem solar cell architectures, particularly those combining perovskite and CIGS, have attracted significant attention owing to their complementary absorption spectra and potential for surpassing the efficiency limits of single-junction devices. This paper presents a comprehensive theoretical comparison between two-terminal (2T) and four-terminal (4T) configurations of perovskite/CIGS tandem solar cells by analyzing their performance characteristics and structural differences. The tandem designs considered in this study are based on a dual-junction layout. The front sub-cell consists of a perovskite film sandwiched between PCBM as an electron transport layer (ETL) and Cu2O as a hole transport layer (HTL). The rear sub-cell consists of a p-type CIGS absorber, integrated with a CdS buffer layer and a ZnO window layer to complete the bottom junction. The optoelectronic properties of each sub-cell are modeled and simulated under standard test conditions to evaluate the photovoltaic (PV) metrics for both 2T and 4T configurations. By comparing the interconnection schemes and operational mechanisms of the two architectures, this work highlights the trade-offs between fabrication complexity and device performance. The results provide valuable insights for guiding the design and optimization of high-efficiency tandem solar cells tailored for commercially feasible PV applications.
{"title":"A simulation-based comparative study of 2T and 4T perovskite/CIGS tandem solar cell configurations","authors":"Marwa Salem , Mostafa M. Salah , Ahmed Shaker , Mohamed Abouelatta , Kawther A. Al-Dhlan , Mohammad T. Alshammari , Tariq S. Almurayziq , Muhammad Tauseef Qureshi , Mohamed Mousa","doi":"10.1016/j.rio.2025.100951","DOIUrl":"10.1016/j.rio.2025.100951","url":null,"abstract":"<div><div>The primary objective of next-generation solar cell technologies is to achieve higher power conversion efficiency (PCE) while maintaining long-term operational stability. Among the promising approaches to meet this demand, tandem solar cell architectures, particularly those combining perovskite and CIGS, have attracted significant attention owing to their complementary absorption spectra and potential for surpassing the efficiency limits of single-junction devices. This paper presents a comprehensive theoretical comparison between two-terminal (2T) and four-terminal (4T) configurations of perovskite/CIGS tandem solar cells by analyzing their performance characteristics and structural differences. The tandem designs considered in this study are based on a dual-junction layout. The front sub-cell consists of a perovskite film sandwiched between PCBM as an electron transport layer (ETL) and Cu<sub>2</sub>O as a hole transport layer (HTL). The rear sub-cell consists of a p-type CIGS absorber, integrated with a CdS buffer layer and a ZnO window layer to complete the bottom junction. The optoelectronic properties of each sub-cell are modeled and simulated under standard test conditions to evaluate the photovoltaic (PV) metrics for both 2T and 4T configurations. By comparing the interconnection schemes and operational mechanisms of the two architectures, this work highlights the trade-offs between fabrication complexity and device performance. The results provide valuable insights for guiding the design and optimization of high-efficiency tandem solar cells tailored for commercially feasible PV applications.</div></div>","PeriodicalId":21151,"journal":{"name":"Results in Optics","volume":"22 ","pages":"Article 100951"},"PeriodicalIF":3.0,"publicationDate":"2025-12-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145797941","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 : 2025-12-13DOI: 10.1016/j.rio.2025.100947
Ian Yulianti , Budi Astuti , M. Alauhdin , Sevia M. Idrus , Muhammad Yusof Mohd. Noor , Nishfa Mufatihah , Mahardika Prasetya Aji , Ngurah Made Darma Putra , Savela Y. Anggaladewi , Joshu Leonardy
This study aimed to explore fabrication of optical waveguides using recycled expanded polystyrene (EPS) as the core material. The recycling process was performed by heating EPS inside the furnace for 2 h, with temperature varying from 200 °C to 280 °C. Refractive index measurement showed that EPS heated at temperature of 200 (EPS200) and 210 (EPS210) exhibited the highest refractive index. Waveguides were fabricated using polymethylmethacrylate (PMMA) sheet as a cladding layer. This sheet was engraved with CNC engraving machine to form a groove at cross-section of 1 × 1 mm2 filled with EPS. Furthermore, characterizations were conducted to investigate propagation loss (PL), temperature-dependent loss (TDL), operating temperature, and time-dependent loss. The results showed that waveguides from EPS200 and EPS210 had the lowest power loss of 3.38 dB and 4.13 dB, respectively, measured at a wavelength of 660 nm. In terms of PL, the fabricated waveguide showed comparable values of 3.46 dB/cm and 3.79 dB/cm for EPS200 and EPS210, respectively. TDL was 7.87 × 10-2 dB/oC and 4.06 × 10-2 dB/oC for EPS200 and EPS210, respectively. Under cyclic temperature loading, waveguides could withstand up to 60 °C. Meanwhile, for prolonged exposure at temperature of 40 °C, there were no significant alterations in terms of power loss.
{"title":"Fabrication and characterization of low-cost optical waveguides using recycled expanded polystyrene (EPS) as core material","authors":"Ian Yulianti , Budi Astuti , M. Alauhdin , Sevia M. Idrus , Muhammad Yusof Mohd. Noor , Nishfa Mufatihah , Mahardika Prasetya Aji , Ngurah Made Darma Putra , Savela Y. Anggaladewi , Joshu Leonardy","doi":"10.1016/j.rio.2025.100947","DOIUrl":"10.1016/j.rio.2025.100947","url":null,"abstract":"<div><div>This study aimed to explore fabrication of optical waveguides using recycled expanded polystyrene (EPS) as the core material. The recycling process was performed by heating EPS inside the furnace for 2 h, with temperature varying from 200 °C to 280 °C. Refractive index measurement showed that EPS heated at temperature of 200 (EPS200) and 210 (EPS210) exhibited the highest refractive index. Waveguides were fabricated using polymethylmethacrylate (PMMA) sheet as a cladding layer. This sheet was engraved with CNC engraving machine to form a groove at cross-section of 1 × 1 mm<sup>2</sup> filled with EPS. Furthermore, characterizations were conducted to investigate propagation loss (PL), temperature-dependent loss (TDL), operating temperature, and time-dependent loss. The results showed that waveguides from EPS200 and EPS210 had the lowest power loss of 3.38 dB and 4.13 dB, respectively, measured at a wavelength of 660 nm. In terms of PL, the fabricated waveguide showed comparable values of 3.46 dB/cm and 3.79 dB/cm for EPS200 and EPS210, respectively. TDL was 7.87 × 10<sup>-2</sup> dB/<sup>o</sup>C and 4.06 × 10<sup>-2</sup> dB/<sup>o</sup>C for EPS200 and EPS210, respectively. Under cyclic temperature loading, waveguides could withstand up to 60 °C. Meanwhile, for prolonged exposure at temperature of 40 °C, there were no significant alterations in terms of power loss.</div></div>","PeriodicalId":21151,"journal":{"name":"Results in Optics","volume":"22 ","pages":"Article 100947"},"PeriodicalIF":3.0,"publicationDate":"2025-12-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145797924","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 proposes a novel hybrid Visible Light Communication (VLC) and Power Line Communication (PLC) framework, optimized through Orthogonal Frequency Division Multiplexing with Quadrature Amplitude Modulation (OFDM-QAM), aiming to enhance spectral efficiency, reliability, and power efficiency in high-speed indoor networks. The proposed architecture exploits the complementary strengths of VLC’s high-capacity optical wireless access and PLC’s cost-efficient wired backbone, providing seamless broadband connectivity in indoor environments. A comprehensive MATLAB-based simulation framework was developed to analyze Bit Error Rate (BER), Error Vector Magnitude (EVM), and Peak-to-Average Power Ratio (PAPR) under varying modulation orders, subcarrier allocations, and channel conditions. Numerical results demonstrate that for a 128-subcarrier OFDM system with 4-QAM, the proposed design achieves a BER of 1.2 × 10-5 at 20 dB Eb/N0, compared to 4.7 × 10-4 for 16-QAM under the same conditions—representing an almost 39 × improvement. Simulation results confirm that the proposed hybrid configuration achieves an EVM of 3.8 %, corresponding to a 52 % relative reduction versus the standalone PLC case with 8.0 %. Additionally, the proposed hybrid scheme yields a 22 % relative EVM improvement (from 4.1 % to 3.2 %) compared to a state-of-the-art predistortion method. A concurrent 18 % PAPR reduction over standalone OFDM is also demonstrated. In comparison to state-of-the-art VLC-RF and PLC-VLC hybrids, the proposed design achieves nearly an order-of-magnitude enhancement in reliability, while maintaining spectral efficiency. These findings establish the hybrid VLC-PLC architecture as a promising candidate for next-generation indoor broadband networks.
本文提出了一种新型的混合可见光通信（VLC）和电力线通信（PLC）框架，该框架通过正交频分复用与正交调幅（OFDM-QAM）进行优化，旨在提高高速室内网络的频谱效率、可靠性和功率效率。所提出的架构利用了VLC的高容量光学无线接入和PLC的低成本有线骨干网的互补优势，在室内环境中提供无缝宽带连接。开发了一个基于matlab的综合仿真框架，用于分析不同调制顺序、子载波分配和信道条件下的误码率（BER）、误差矢量幅度（EVM）和峰均功率比（PAPR）。数值结果表明，对于具有4-QAM的128子载波OFDM系统，所提出的设计在20 dB Eb/N0下实现了1.2 × 10-5的误码率，而在相同条件下，16-QAM的误码率为4.7 × 10-4，几乎提高了39倍。仿真结果证实，所提出的混合配置实现了3.8%的EVM，与独立PLC的8.0%相比，相对降低了52%。此外，与最先进的预失真方法相比，所提出的混合方案相对EVM提高了22%（从4.1%降至3.2%）。在独立OFDM的基础上，还演示了18%的PAPR降低。与最先进的VLC-RF和PLC-VLC混合电路相比，该设计在保持频谱效率的同时，在可靠性方面提高了近一个数量级。这些发现确立了vllc - plc混合架构作为下一代室内宽带网络的有前途的候选者。
{"title":"Performance optimization of hybrid VLC-PLC systems using OFDM-QAM modulation for High-Speed indoor communications","authors":"Saeed Najafi Chabok, Gholamreza Baghersalimi, Hossein Goorani","doi":"10.1016/j.rio.2025.100946","DOIUrl":"10.1016/j.rio.2025.100946","url":null,"abstract":"<div><div>This paper proposes a novel hybrid Visible Light Communication (VLC) and Power Line Communication (PLC) framework, optimized through Orthogonal Frequency Division Multiplexing with Quadrature Amplitude Modulation (OFDM-QAM), aiming to enhance spectral efficiency, reliability, and power efficiency in high-speed indoor networks. The proposed architecture exploits the complementary strengths of VLC’s high-capacity optical wireless access and PLC’s cost-efficient wired backbone, providing seamless broadband connectivity in indoor environments. A comprehensive MATLAB-based simulation framework was developed to analyze Bit Error Rate (BER), Error Vector Magnitude (EVM), and Peak-to-Average Power Ratio (PAPR) under varying modulation orders, subcarrier allocations, and channel conditions. Numerical results demonstrate that for a 128-subcarrier OFDM system with 4-QAM, the proposed design achieves a BER of 1.2 × 10<sup>-5</sup> at 20 dB <em>E<sub>b</sub></em>/<em>N</em><sub>0</sub>, compared to 4.7 × 10<sup>-4</sup> for 16-QAM under the same conditions—representing an almost 39 × improvement. Simulation results confirm that the proposed hybrid configuration achieves an EVM of 3.8 %, corresponding to a 52 % relative reduction versus the standalone PLC case with 8.0 %. Additionally, the proposed hybrid scheme yields a 22 % relative EVM improvement (from 4.1 % to 3.2 %) compared to a state-of-the-art predistortion method. A concurrent 18 % PAPR reduction over standalone OFDM is also demonstrated. In comparison to state-of-the-art VLC-RF and PLC-VLC hybrids, the proposed design achieves nearly an order-of-magnitude enhancement in reliability, while maintaining spectral efficiency. These findings establish the hybrid VLC-PLC architecture as a promising candidate for next-generation indoor broadband networks.</div></div>","PeriodicalId":21151,"journal":{"name":"Results in Optics","volume":"22 ","pages":"Article 100946"},"PeriodicalIF":3.0,"publicationDate":"2025-12-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145797923","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 : 2025-12-13DOI: 10.1016/j.rio.2025.100945
Florian Rackerseder , Helen Bolek , Martin Traub , Lucas Warnecke , Sarah Klein , Friederike Brackmann , Mark Pätzel , Jan Kallweit , Robert Seewald , Alexander Schiebahn , Constantin Häfner
Within this work, an optical system was developed for coupling 405 nm laser radiation into a bundle of polymer optical fibers (POF) for a UV curing application. Traditional UV curing methods require at least one transparent joining partner, which limits their use in certain industrial applications. To enable efficient light coupling even between non-transparent materials, a novel bonding process has been developed that uses sidelight-activated POF woven into a fabric. By lateral emission from the fabric, the radiation reaches the bonding zone, so that the adhesive is cured over a large area.
The optical system aims to achieve homogeneous illumination in the bonding zone by employing a diode laser, which offers advantages over traditional LED sources, particularly in terms of absorption efficiency of UV adhesives. The system is characterized by its coupling efficiency and the feasible homogeneity of the intensity profile in the image plane. Both quantities have been determined experimentally and by simulation with Zemax OpticStudio, achieving a coupling efficiency of up to 74% and a homogeneity exceeding 95% in the focal plane.
Further investigation into the distribution of defects inside the fiber revealed that specific parameters significantly influence the homogeneity of lateral light emission. The results indicate that a tailored defect configuration can optimize the curing process, paving the way for future applications in industrial adhesive bonding. The findings underscore the potential for commercialization of this innovative optical coupling system within manufacturing sectors requiring efficient and large-area UV curing solutions.
{"title":"405 nm diode laser system for curing UV adhesives based on embedded sidelight-activated polymer optical fibers","authors":"Florian Rackerseder , Helen Bolek , Martin Traub , Lucas Warnecke , Sarah Klein , Friederike Brackmann , Mark Pätzel , Jan Kallweit , Robert Seewald , Alexander Schiebahn , Constantin Häfner","doi":"10.1016/j.rio.2025.100945","DOIUrl":"10.1016/j.rio.2025.100945","url":null,"abstract":"<div><div>Within this work, an optical system was developed for coupling 405 nm laser radiation into a bundle of polymer optical fibers (POF) for a UV curing application. Traditional UV curing methods require at least one transparent joining partner, which limits their use in certain industrial applications. To enable efficient light coupling even between non-transparent materials, a novel bonding process has been developed that uses sidelight-activated POF woven into a fabric. By lateral emission from the fabric, the radiation reaches the bonding zone, so that the adhesive is cured over a large area.</div><div>The optical system aims to achieve homogeneous illumination in the bonding zone by employing a diode laser, which offers advantages over traditional LED sources, particularly in terms of absorption efficiency of UV adhesives. The system is characterized by its coupling efficiency and the feasible homogeneity of the intensity profile in the image plane. Both quantities have been determined experimentally and by simulation with Zemax OpticStudio, achieving a coupling efficiency of up to 74% and a homogeneity exceeding 95% in the focal plane.</div><div>Further investigation into the distribution of defects inside the fiber revealed that specific parameters significantly influence the homogeneity of lateral light emission. The results indicate that a tailored defect configuration can optimize the curing process, paving the way for future applications in industrial adhesive bonding. The findings underscore the potential for commercialization of this innovative optical coupling system within manufacturing sectors requiring efficient and large-area UV curing solutions.</div></div>","PeriodicalId":21151,"journal":{"name":"Results in Optics","volume":"22 ","pages":"Article 100945"},"PeriodicalIF":3.0,"publicationDate":"2025-12-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145797940","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 : 2025-12-11DOI: 10.1016/j.rio.2025.100944
V. Kalaipoonguzhali , Sandeep Prabhu , U. Arun Kumar , R. Dhivya
This study presents a high-sensitivity metasurface-based biosensor for COVID-19 detection, incorporating advanced two-dimensional materials which includes graphene, borophene, MoS2, phosphorene, and germanene. The design consists of a graphene base layer supporting two phosphorene-coated rectangular resonators, a germanene-coated central circular resonator, and a MoS2-coated concentric ring structure. COMSOL Multiphysics simulations demonstrate an exceptionally high refractive-index sensitivity of 667 GHz RIU−1 within the 1.334–1.355 RIU range. Machine-learning-assisted optimization using polynomial regression enhances predictive reliability, achieving R2 values between 87 % and 100 %. The proposed sensor exhibits a detection accuracy of 32.258 and a maximum figure of merit (FOM) of 21.505 RIU−1, indicating strong potential for rapid and precise point-of-care COVID-19 diagnostics. Furthermore, the sensor maintains stable performance under varying incidence angles (0–80°) and tunable graphene chemical potentials (0.1–0.9 eV), confirming its robustness and practical adaptability.
{"title":"Angle-robust hybrid 2D-material metasurface biosensor for COVID-19 detection with machine-learning optimization","authors":"V. Kalaipoonguzhali , Sandeep Prabhu , U. Arun Kumar , R. Dhivya","doi":"10.1016/j.rio.2025.100944","DOIUrl":"10.1016/j.rio.2025.100944","url":null,"abstract":"<div><div>This study presents a high-sensitivity metasurface-based biosensor for COVID-19 detection, incorporating advanced two-dimensional materials which includes graphene, borophene, MoS<sub>2</sub>, phosphorene, and germanene. The design consists of a graphene base layer supporting two phosphorene-coated rectangular resonators, a germanene-coated central circular resonator, and a MoS<sub>2</sub>-coated concentric ring structure. COMSOL Multiphysics simulations demonstrate an exceptionally high refractive-index sensitivity of 667 GHz RIU<sup>−1</sup> within the 1.334–1.355 RIU range. Machine-learning-assisted optimization using polynomial regression enhances predictive reliability, achieving R<sup>2</sup> values between 87 % and 100 %. The proposed sensor exhibits a detection accuracy of 32.258 and a maximum figure of merit (FOM) of 21.505 RIU<sup>−1</sup>, indicating strong potential for rapid and precise point-of-care COVID-19 diagnostics. Furthermore, the sensor maintains stable performance under varying incidence angles (0–80°) and tunable graphene chemical potentials (0.1–0.9 eV), confirming its robustness and practical adaptability.</div></div>","PeriodicalId":21151,"journal":{"name":"Results in Optics","volume":"22 ","pages":"Article 100944"},"PeriodicalIF":3.0,"publicationDate":"2025-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145797942","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 : 2025-12-11DOI: 10.1016/j.rio.2025.100943
Lingxi Liu, Lihe Yan, Jinhai Si, Xun Hou
To address the core challenges of complex noise, insufficient feature utilization, and poor task collaboration in structured light 3D scanning, this paper presents a graph neural network, named StructuredLight-GNN. By integrating confidence-aware mechanisms, attention mechanisms, and multi-scale feature extraction modules, the network constructs an end-to-end framework that enables collaborative processing across the entire “denoising - optimization - detection” pipeline for structured light point clouds. Key innovations include confidence-fused adaptive graph construction, multi-branch heterogeneous feature extraction, multi-task joint optimization, and hierarchical multi-scale processing. The network effectively handles complex noise patterns in structured light scans, such as phase unwrapping errors, ambient light-induced outliers, Gray code decoding failures, and blocky missing points caused by highly reflective surfaces. It also accurately identifies imaged objects even in the presence of obstacles and interference, demonstrating the significant potential of graph neural networks in structured light 3D scanning.
{"title":"StructuredLight-GNN: A graph neural network for end-to-end structured light 3D point cloud processing","authors":"Lingxi Liu, Lihe Yan, Jinhai Si, Xun Hou","doi":"10.1016/j.rio.2025.100943","DOIUrl":"10.1016/j.rio.2025.100943","url":null,"abstract":"<div><div>To address the core challenges of complex noise, insufficient feature utilization, and poor task collaboration in structured light 3D scanning, this paper presents a graph neural network, named StructuredLight-GNN. By integrating confidence-aware mechanisms, attention mechanisms, and multi-scale feature extraction modules, the network constructs an end-to-end framework that enables collaborative processing across the entire “denoising - optimization - detection” pipeline for structured light point clouds. Key innovations include confidence-fused adaptive graph construction, multi-branch heterogeneous feature extraction, multi-task joint optimization, and hierarchical multi-scale processing. The network effectively handles complex noise patterns in structured light scans, such as phase unwrapping errors, ambient light-induced outliers, Gray code decoding failures, and blocky missing points caused by highly reflective surfaces. It also accurately identifies imaged objects even in the presence of obstacles and interference, demonstrating the significant potential of graph neural networks in structured light 3D scanning.</div></div>","PeriodicalId":21151,"journal":{"name":"Results in Optics","volume":"22 ","pages":"Article 100943"},"PeriodicalIF":3.0,"publicationDate":"2025-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145748533","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 novel 16-input, 4-output electro-optical encoder utilizing tunable resonant cavities. Light transmission through a silicon waveguide is modulated by a nearby photonic crystal cavity comprising 20 air holes. These air holes form a resonant cavity, filtering out unwanted wavelengths. A graphene-aluminum oxide stack within the cavity controls the filter’s properties by adjusting the graphene’s chemical potential. This configuration creates an electro-optical switch, with seven such switches directing light from input bias ports to four output ports. The device’s area and the contrast ratio are 200 µm2 and 10.61 dB, respectively. The modulation depth of 96.4 % and the crosstalk of −13.52 dB are additional advantages of the designed encoder. The tunability of the transmission efficiency for the designed switches as the basis block is an interesting feature of the designed encoder. Moreover, the design is scalable, allowing for expansion to larger systems, a crucial requirement for advanced optical circuits and networks.
{"title":"Development of a high-performance 16-to-4 electro-optical encoder using photonic crystal resonant cavities","authors":"Fatemeh Haddadan , Mohammad Soroosh , Haraprasad Mondal , Sandip Swarnakar , Ehsan Adibnia","doi":"10.1016/j.rio.2025.100941","DOIUrl":"10.1016/j.rio.2025.100941","url":null,"abstract":"<div><div>This paper presents a novel 16-input, 4-output electro-optical encoder utilizing tunable resonant cavities. Light transmission through a silicon waveguide is modulated by a nearby photonic crystal cavity comprising 20 air holes. These air holes form a resonant cavity, filtering out unwanted wavelengths. A graphene-aluminum oxide stack within the cavity controls the filter’s properties by adjusting the graphene’s chemical potential. This configuration creates an electro-optical switch, with seven such switches directing light from input bias ports to four output ports. The device’s area and the contrast ratio are 200 µm<sup>2</sup> and 10.61 dB, respectively. The modulation depth of 96.4 % and the crosstalk of −13.52 dB are additional advantages of the designed encoder. The tunability of the transmission efficiency for the designed switches as the basis block is an interesting feature of the designed encoder. Moreover, the design is scalable, allowing for expansion to larger systems, a crucial requirement for advanced optical circuits and networks.</div></div>","PeriodicalId":21151,"journal":{"name":"Results in Optics","volume":"22 ","pages":"Article 100941"},"PeriodicalIF":3.0,"publicationDate":"2025-12-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145748535","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 : 2025-12-05DOI: 10.1016/j.rio.2025.100939
Mohamed Moustafa , Ahmed A. El-Naggar , Ziad Abu Waar , Mahmoud Abdelfatah , Abdelhamid El-Shaer
Copper-zinc tin sulfide (Cu2ZnSnS4 or CZTS), a quaternary semiconductor with superior optoelectronic properties, has emerged as a promising absorber material for thin-film photovoltaic applications. In this study, a high-efficiency CZTS solar cell was numerically investigated using SCAPS-1D, emphasizing the roles of Cu2O as a hole transport layer (HTL) and Cd0.4Zn0.6S as a tunable buffer layer. The simulated device structure—ITO/AZO/Cd0.4Zn0.6S /CZTS/Cu2O/Mo—was systematically optimized by varying the thickness and bandgap of each functional layer. The best performance was achieved with a 0.01 µm-thick Cu2O HTL (2.2 eV bandgap) and a 0.01 µm-thick Cd0.4Zn0.6S buffer (2.98 eV bandgap), enabling efficient hole extraction, high transparency, and suppressed interfacial recombination. Under these optimized conditions, the device exhibited an open-circuit voltage (Voc) of 0.867 V, short-circuit current density (Jsc) of 43.424 mA/cm2, Fill Factor (FF) of 82.23 %, and a remarkable power conversion efficiency (PCE) of 31.18 %. Additionally, the influence of operating temperature on solar cell performance was evaluated in the range of 280 K to 360 K. The results revealed a notable reduction in the PCE, decreasing from 32.19 % to 27.57 %. This degradation in efficiency is primarily attributed to the temperature-induced increase in reverse saturation current, which adversely impacts the Voc and overall device performance. The interface defect studies revealed severe performance degradation, with efficiency reduced to 21.75 % at a defect density of 1 × 1020 cm−3 at the CZTS/Cd0.4Zn0.6S junction. These findings underscore the critical importance of HTL/buffer layer engineering, interface defect control, and thermal management in advancing high-efficiency, thermally stable, and environmentally benign CZTS-based solar cells.
{"title":"Performance enhancement of CZTS solar cells via Cu2O HTL and Cd0.4Zn0.6S buffer layer: a numerical study","authors":"Mohamed Moustafa , Ahmed A. El-Naggar , Ziad Abu Waar , Mahmoud Abdelfatah , Abdelhamid El-Shaer","doi":"10.1016/j.rio.2025.100939","DOIUrl":"10.1016/j.rio.2025.100939","url":null,"abstract":"<div><div>Copper-zinc tin sulfide (Cu<sub>2</sub>ZnSnS<sub>4</sub> or CZTS), a quaternary semiconductor with superior optoelectronic properties, has emerged as a promising absorber material for thin-film photovoltaic applications. In this study, a high-efficiency CZTS solar cell was numerically investigated using SCAPS-1D, emphasizing the roles of Cu<sub>2</sub>O as a hole transport layer (HTL) and Cd<sub>0.4</sub>Zn<sub>0.6</sub>S as a tunable buffer layer. The simulated device structure—ITO/AZO/Cd<sub>0.4</sub>Zn<sub>0.6</sub>S /CZTS/Cu<sub>2</sub>O/Mo—was systematically optimized by varying the thickness and bandgap of each functional layer. The best performance was achieved with a 0.01 µm-thick Cu<sub>2</sub>O HTL (2.2 eV bandgap) and a 0.01 µm-thick Cd<sub>0.4</sub>Zn<sub>0.6</sub>S buffer (2.98 eV bandgap), enabling efficient hole extraction, high transparency, and suppressed interfacial recombination. Under these optimized conditions, the device exhibited an open-circuit voltage (V<sub>oc</sub>) of 0.867 V, short-circuit current density (J<sub>sc</sub>) of 43.424 mA/cm<sup>2</sup>, Fill Factor (FF) of 82.23 %, and a remarkable power conversion efficiency (PCE) of 31.18 %. Additionally, the influence of operating temperature on solar cell performance was evaluated in the range of 280 K to 360 K. The results revealed a notable reduction in the PCE, decreasing from 32.19 % to 27.57 %. This degradation in efficiency is primarily attributed to the temperature-induced increase in reverse saturation current, which adversely impacts the V<sub>oc</sub> and overall device performance. The interface defect studies revealed severe performance degradation, with efficiency reduced to 21.75 % at a defect density of 1 × 10<sup>20</sup> cm<sup>−3</sup> at the CZTS/Cd<sub>0.4</sub>Zn<sub>0.6</sub>S junction. These findings underscore the critical importance of HTL/buffer layer engineering, interface defect control, and thermal management in advancing high-efficiency, thermally stable, and environmentally benign CZTS-based solar cells.</div></div>","PeriodicalId":21151,"journal":{"name":"Results in Optics","volume":"22 ","pages":"Article 100939"},"PeriodicalIF":3.0,"publicationDate":"2025-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145797939","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}
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