Pub Date : 2025-01-16DOI: 10.1016/j.ijleo.2025.172230
R. Samson Daniel
Asymmetric Coplanar Strip (ACS)-Fed with loop resonators is fashioned in the form of nested configuration, which imparts multiband radiation. By forming nested loops, it increases the number resonance substantially. An invented antenna possesses five rectangular loops, which induces the antenna to radiate 1.17 GHz, 1.74 GHz, 2.31 GHz, 2.93 GHz, 3.63 GHz and 5 GHz frequencies. The developed antenna is amalgamated by ACS-fed with loop resonators, it has been fabricated on a FR-4 substrate having the size of 18181.6 mm3, = 4.4 and = 0.02. To ascertain the optimal peak gain of the antenna, Frequency Selective Surface (FSS) amelioration approach has been carried out. It is fashioned on 44.544.50.8 mm3 FR-4 substrate by 44 FSS array configurations. At 5 GHz resonance, the antenna imparts the peak gain of 0.52 dBi without FSS. To meliorate the peak gain, the antenna is covered by 44 FSS array, which executes as the reflector for rendering the peak gain of 6.62 dBi. The transmission line model of FSS unit cell has been explored with the help of LC values to identity the band reject mechanisms, which is examined by Agilent ADS software. The calibrated radiation factors of the fabricated antenna with FSS cover endorse simulated counterparts, which is suitable for GSM, WiMAX and WLAN applications.
{"title":"Asymmetric Coplanar Strip‑Fed multiband loop antenna with FSS cover for gain improvement","authors":"R. Samson Daniel","doi":"10.1016/j.ijleo.2025.172230","DOIUrl":"10.1016/j.ijleo.2025.172230","url":null,"abstract":"<div><div>Asymmetric Coplanar Strip (ACS)-Fed with loop resonators is fashioned in the form of nested configuration, which imparts multiband radiation. By forming nested loops, it increases the number resonance substantially. An invented antenna possesses five rectangular loops, which induces the antenna to radiate 1.17 GHz, 1.74 GHz, 2.31 GHz, 2.93 GHz, 3.63 GHz and 5 GHz frequencies. The developed antenna is amalgamated by ACS-fed with loop resonators, it has been fabricated on a FR-4 substrate having the size of 18<span><math><mo>×</mo></math></span>18<span><math><mo>×</mo></math></span>1.6 mm<sup>3</sup>, <span><math><msub><mrow><mi>ε</mi></mrow><mrow><mi>r</mi></mrow></msub></math></span>= 4<sup>.</sup>4 and <span><math><mrow><mi>tan</mi><mrow><mi>δ</mi></mrow></mrow></math></span> = 0.02. To ascertain the optimal peak gain of the antenna, Frequency Selective Surface (FSS) amelioration approach has been carried out. It is fashioned on 44.5<span><math><mo>×</mo></math></span>44.5<span><math><mo>×</mo></math></span>0.8 mm<sup>3</sup> FR-4 substrate by 4<span><math><mo>×</mo></math></span>4 FSS array configurations. At 5 GHz resonance, the antenna imparts the peak gain of 0.52 dBi without FSS. To meliorate the peak gain, the antenna is covered by 4<span><math><mo>×</mo></math></span>4 FSS array, which executes as the reflector for rendering the peak gain of 6.62 dBi. The transmission line model of FSS unit cell has been explored with the help of LC values to identity the band reject mechanisms, which is examined by Agilent ADS software. The calibrated radiation factors of the fabricated antenna with FSS cover endorse simulated counterparts, which is suitable for GSM, WiMAX and WLAN applications.</div></div>","PeriodicalId":19513,"journal":{"name":"Optik","volume":"323 ","pages":"Article 172230"},"PeriodicalIF":3.1,"publicationDate":"2025-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143183013","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}
The paper demonstrates the research of a fiber Bragg gratings inscription method including translation of a laser beam relative to a phase mask. Passing laser radiation through a phase mask results in diffraction into +1 and −1 orders, which makes it possible to inscribe FBGs inside a fiber core and the laser beam translation allows to obtain long apodized gratings. For each Bragg grating, the dependences of optical characteristics on the parameters of laser radiation are established. The result of inscription FBGs to obtain laser generation is presented in the article as well.
{"title":"Research of fiber Bragg gratings inscription by the method of translation of a laser beam relative to a phase mask","authors":"V.A. Yakimuk, S.V. Varzhel, I.D. Moor, Y.I. Yandybaeva, U.R. Korobkova, V.A. Klishina, A.V. Kulikov","doi":"10.1016/j.ijleo.2025.172216","DOIUrl":"10.1016/j.ijleo.2025.172216","url":null,"abstract":"<div><div>The paper demonstrates the research of a fiber Bragg gratings inscription method including translation of a laser beam relative to a phase mask. Passing laser radiation through a phase mask results in diffraction into +1 and −1 orders, which makes it possible to inscribe FBGs inside a fiber core and the laser beam translation allows to obtain long apodized gratings. For each Bragg grating, the dependences of optical characteristics on the parameters of laser radiation are established. The result of inscription FBGs to obtain laser generation is presented in the article as well.</div></div>","PeriodicalId":19513,"journal":{"name":"Optik","volume":"323 ","pages":"Article 172216"},"PeriodicalIF":3.1,"publicationDate":"2025-01-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143183011","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 : 2025-01-15DOI: 10.1016/j.ijleo.2025.172225
Li Min , Keyuan Wang
A multifunctional terahertz element (MTE) was constructed with a silicon substrate etched with periodically distributed rectangular holes, integrating the functions of a quarter-wave plate, half-wave plate, and reflector. Results show that the quarter-wave plate has a transmittance of over 90 % within a bandwidth exceeding 1 THz, the half-wave plate achieves nearly 100 % polarization conversion efficiency at 5 THz, and the reflector maintains 100 % reflectivity within the frequency range of 13 THz to 21 THz. It suitable for photonic chip integration to achieve polarization control and filtering, with broad applications in sensing, detection, and photonic computing.
{"title":"Terahertz multifunctional elements based on all-dielectric metamaterials","authors":"Li Min , Keyuan Wang","doi":"10.1016/j.ijleo.2025.172225","DOIUrl":"10.1016/j.ijleo.2025.172225","url":null,"abstract":"<div><div>A multifunctional terahertz element (MTE) was constructed with a silicon substrate etched with periodically distributed rectangular holes, integrating the functions of a quarter-wave plate, half-wave plate, and reflector. Results show that the quarter-wave plate has a transmittance of over 90 % within a bandwidth exceeding 1 THz, the half-wave plate achieves nearly 100 % polarization conversion efficiency at 5 THz, and the reflector maintains 100 % reflectivity within the frequency range of 13 THz to 21 THz. It suitable for photonic chip integration to achieve polarization control and filtering, with broad applications in sensing, detection, and photonic computing.</div></div>","PeriodicalId":19513,"journal":{"name":"Optik","volume":"323 ","pages":"Article 172225"},"PeriodicalIF":3.1,"publicationDate":"2025-01-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143183009","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}
In this study, a single crystal of 2,4-dihydroxybenzophenone (DHBP) was grown using the vertical Bridgman method using a custom-designed double zone furnace. DSC revealed the melting and freezing points of DHBP as 149 ℃ and 61 ℃, respectively. A transparent Bridgman furnace with a steep temperature gradient was employed to accommodate the significant phase change temperature difference. The conventional V-shaped ampoule was modified with a shorter cone length and angle to optimize the growth process. X-ray diffraction (XRD) confirmed the monoclinic structure (P21/c) of the DHBP crystal retained post-melting and crystallization. High-resolution XRD revealed excellent crystalline perfection of the grown DHBP crystal with an FWHM of 154” for the (0 2 0) lattice plane. The FTIR and FT-Raman analyses confirmed the functional groups of the melt-grown DHBP single crystal aligned well with those of the solution-grown crystal. The grown DHBP shows 70 % transmittance (450–1000 nm), a 390 nm cut-off, an optical band gap of 3.13 eV and an Urbach energy of 0.11 eV. Photoconductivity analysis revealed that the as-grown crystal in the (0 2 0) plane acquired negative conductivity. Photoluminescence studies revealed fluorescence at 530 nm under 390 nm excitation. A Z-scan experiment was performed using both CW He-Ne laser (632 nm) and Nd:YAG pulsed laser (532 nm) to explore third-order NLO properties. The DHBP crystal demonstrates reverse saturable absorption, attributed to the phenomenon of two-photon absorption. According to pure electronic nonlinearity, the nonlinear absorption coefficient and optical limiting threshold were determined to be 5.4 × 10−11 m/W and 3.24 × 1012 W/m2, respectively.
{"title":"Unveiling two-photon absorption dynamic in melt grown 2,4-dihydroxybenzophenone (DHBP) single crystal: Insights from bridgman method using double-zone glass furnace","authors":"Mohamad Asikali Abdul Hakkim , Rajesh Paulraj , Sabari Girisun T.C.","doi":"10.1016/j.ijleo.2025.172215","DOIUrl":"10.1016/j.ijleo.2025.172215","url":null,"abstract":"<div><div>In this study, a single crystal of 2,4-dihydroxybenzophenone (DHBP) was grown using the vertical Bridgman method using a custom-designed double zone furnace. DSC revealed the melting and freezing points of DHBP as 149 ℃ and 61 ℃, respectively. A transparent Bridgman furnace with a steep temperature gradient was employed to accommodate the significant phase change temperature difference. The conventional V-shaped ampoule was modified with a shorter cone length and angle to optimize the growth process. X-ray diffraction (XRD) confirmed the monoclinic structure (P2<sub>1/c</sub>) of the DHBP crystal retained post-melting and crystallization. High-resolution XRD revealed excellent crystalline perfection of the grown DHBP crystal with an FWHM of 154” for the (0 2 0) lattice plane. The FTIR and FT-Raman analyses confirmed the functional groups of the melt-grown DHBP single crystal aligned well with those of the solution-grown crystal. The grown DHBP shows 70 % transmittance (450–1000 nm), a 390 nm cut-off, an optical band gap of 3.13 eV and an Urbach energy of 0.11 eV. Photoconductivity analysis revealed that the as-grown crystal in the (0 2 0) plane acquired negative conductivity. Photoluminescence studies revealed fluorescence at 530 nm under 390 nm excitation. A Z-scan experiment was performed using both CW He-Ne laser (632 nm) and Nd:YAG pulsed laser (532 nm) to explore third-order NLO properties. The DHBP crystal demonstrates reverse saturable absorption, attributed to the phenomenon of two-photon absorption. According to pure electronic nonlinearity, the nonlinear absorption coefficient and optical limiting threshold were determined to be 5.4 × 10<sup>−11</sup> m/W and 3.24 × 10<sup>12</sup> W/m<sup>2</sup>, respectively.</div></div>","PeriodicalId":19513,"journal":{"name":"Optik","volume":"323 ","pages":"Article 172215"},"PeriodicalIF":3.1,"publicationDate":"2025-01-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143183010","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 : 2025-01-09DOI: 10.1016/j.ijleo.2025.172214
Sadia Waheed , Shazia Bashir , Gin Jose , Robert Mathieson , Eric Kumi Barimah , Asma Hayat , Muhammad Rana Ayub
The effect of environmental conditions and irradiances on femtosecond laser-induced breakdown spectroscopy of Aluminum (Al) plasma has been investigated. For this purpose, a femtosecond laser (1030 nm, 220 fs) was employed to irradiate the Al targets under air and vacuum environments at different laser irradiances ranging from 1.8 TWcm−2 to 5.4 TWcm−2. LIBS analysis shows that optical intensity of emission spectra and plasma parameters (electron temperature “Te” and electron number density “ne”) are increased with increasing the laser irradiances of Al plasma under both environments. The electron temperature is evaluated by using both Boltzmann and Saha Boltzmann distributions, whereas electron density is evaluated by using Stark broadening. With increasing laser irradiances, the values of Te of Al plasma increases from 8061 K to 8745 K under vacuum environment, whereas, for air Te increases from 8203 K to 8874 K. In case of Saha Boltzmann plot, the values of Te under vacuum vary from 8467 K to 8949 K and in air environment the estimated values of Te increases from the 8600 K to 9027 K. Likewise, the values of ne of Al plasma vary from 8.52 x 1018 cm−3 to 9.22 x 1018 cm−3 under vacuum environmental condition, while in case of air, the values of ne vary from 8.72 x 1018 cm−3 to 9.38 x 1018 cm−3. Slightly higher values of Al plasma parameters in air as compared to vacuum are explainable on the basis of confinement effect offered by 760 Torr atmospheric pressure. The air environment restricts free expansion of Al plasma that results into enhanced rate of collisional excitation, recombination with increased life time of plasma that slows down the plasma plume. The laser-target interaction process of air also causes exothermic reactions of reactive gases (H2, O2, CO2 etc) which are responsible for enhanced energy coupling to target in addition to laser energy deposition which in turn increases ablation rate and evaporation of the target. The increasing trends of emission intensity and plasma parameters with the increasing laser irradiances are attributed to enhanced mass ablation rate due to more energy deposition that increases the excitation and de-excitation within the plasma. The higher values of Al plasma parameters under certain environments make it more beneficial for various applications including surface structuring, electron ion implantation, pulse laser deposition of thin films and other industrial applications.
{"title":"Femtosecond laser-induced breakdown spectroscopy of aluminum plasma under the vacuum & air environments at various laser irradiances","authors":"Sadia Waheed , Shazia Bashir , Gin Jose , Robert Mathieson , Eric Kumi Barimah , Asma Hayat , Muhammad Rana Ayub","doi":"10.1016/j.ijleo.2025.172214","DOIUrl":"10.1016/j.ijleo.2025.172214","url":null,"abstract":"<div><div>The effect of environmental conditions and irradiances on femtosecond laser-induced breakdown spectroscopy of Aluminum (Al) plasma has been investigated. For this purpose, a femtosecond laser (1030 nm, 220 fs) was employed to irradiate the Al targets under air and vacuum environments at different laser irradiances ranging from 1.8 TWcm<sup>−2</sup> to 5.4 TWcm<sup>−2</sup>. LIBS analysis shows that optical intensity of emission spectra and plasma parameters (electron temperature “T<sub>e</sub>” and electron number density “n<sub>e</sub>”) are increased with increasing the laser irradiances of Al plasma under both environments. The electron temperature is evaluated by using both Boltzmann and Saha Boltzmann distributions, whereas electron density is evaluated by using Stark broadening. With increasing laser irradiances, the values of T<sub>e</sub> of Al plasma increases from 8061 K to 8745 K under vacuum environment, whereas, for air T<sub>e</sub> increases from 8203 K to 8874 K. In case of Saha Boltzmann plot, the values of T<sub>e</sub> under vacuum vary from 8467 K to 8949 K and in air environment the estimated values of T<sub>e</sub> increases from the 8600 K to 9027 K. Likewise, the values of n<sub>e</sub> of Al plasma vary from 8.52 x 10<sup>18</sup> cm<sup>−3</sup> to 9.22 x 10<sup>18</sup> cm<sup>−3</sup> under vacuum environmental condition, while in case of air, the values of n<sub>e</sub> vary from 8.72 x 10<sup>18</sup> cm<sup>−3</sup> to 9.38 x 10<sup>18</sup> cm<sup>−3</sup>. Slightly higher values of Al plasma parameters in air as compared to vacuum are explainable on the basis of confinement effect offered by 760 Torr atmospheric pressure. The air environment restricts free expansion of Al plasma that results into enhanced rate of collisional excitation, recombination with increased life time of plasma that slows down the plasma plume. The laser-target interaction process of air also causes exothermic reactions of reactive gases (H<sub>2</sub>, O<sub>2</sub>, CO<sub>2</sub> etc) which are responsible for enhanced energy coupling to target in addition to laser energy deposition which in turn increases ablation rate and evaporation of the target. The increasing trends of emission intensity and plasma parameters with the increasing laser irradiances are attributed to enhanced mass ablation rate due to more energy deposition that increases the excitation and de-excitation within the plasma. The higher values of Al plasma parameters under certain environments make it more beneficial for various applications including surface structuring, electron ion implantation, pulse laser deposition of thin films and other industrial applications.</div></div>","PeriodicalId":19513,"journal":{"name":"Optik","volume":"324 ","pages":"Article 172214"},"PeriodicalIF":3.1,"publicationDate":"2025-01-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143178887","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 : 2025-01-06DOI: 10.1016/j.ijleo.2025.172213
Amegha Sahni , S. Deepika , C. Nagarajan , Seunghwoi Han , J. Kawya , T.C. Sabari Girisun , K. Manirahulan , N. Angeline Little Flower , R. Annie Sujatha
The optical limiting study of intrinsic and cobalt doped ZnO has been carried out in the ns regime with varying dopant concentrations. The flower-like structured, polycrystalline wurtzite ZnO has been revealed by the structural and morphological data. Presence of cobalt ions was confirmed by the Raman peaks corresponding to the Co-O-Zn vibrations and absorption peaks indicating d-d transitions in cobalt (II) ions. The single beam Z- scan technique with nano pulsed Nd-YAG laser is employed to study the nonlinear optical responses and optical limiting studies. While 5 % doped samples showed the lowest optical limiting threshold value of 18.8 GW/cm2, 1 % and 3 % doped samples exhibited higher values than intrinsic ZnO. Intensity-varying nonlinear optical studies have also been performed to confirm the defects-assisted sequential two-photon absorption (2PA), which promoted the reverse saturable absorption (RSA) characteristics of the materials.
{"title":"Defect-driven sequential two-photon absorption for enhanced optical limiting in Co:ZnO","authors":"Amegha Sahni , S. Deepika , C. Nagarajan , Seunghwoi Han , J. Kawya , T.C. Sabari Girisun , K. Manirahulan , N. Angeline Little Flower , R. Annie Sujatha","doi":"10.1016/j.ijleo.2025.172213","DOIUrl":"10.1016/j.ijleo.2025.172213","url":null,"abstract":"<div><div>The optical limiting study of intrinsic and cobalt doped ZnO has been carried out in the ns regime with varying dopant concentrations. The flower-like structured, polycrystalline wurtzite ZnO has been revealed by the structural and morphological data. Presence of cobalt ions was confirmed by the Raman peaks corresponding to the Co-O-Zn vibrations and absorption peaks indicating d-d transitions in cobalt (II) ions. The single beam Z- scan technique with nano pulsed Nd-YAG laser is employed to study the nonlinear optical responses and optical limiting studies. While 5 % doped samples showed the lowest optical limiting threshold value of 18.8 GW/cm<sup>2</sup>, 1 % and 3 % doped samples exhibited higher values than intrinsic ZnO. Intensity-varying nonlinear optical studies have also been performed to confirm the defects-assisted sequential two-photon absorption (2PA), which promoted the reverse saturable absorption (RSA) characteristics of the materials.</div></div>","PeriodicalId":19513,"journal":{"name":"Optik","volume":"323 ","pages":"Article 172213"},"PeriodicalIF":3.1,"publicationDate":"2025-01-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143183007","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 : 2025-01-04DOI: 10.1016/j.ijleo.2024.172212
Dokhyl AlQahtani , Fady El-Nahal
The demand for optical networks that offer low latency and high capacity is increasing with the rise of next-generation cellular systems. Centralized Radio Access Network (C-RAN) architecture provides a cost-effective approach to mobile network deployment. To enhance flexibility and minimize fronthaul network implementation expenses, we propose a bidirectional fronthaul C-RAN configuration that combines coherent Wavelength Division Multiplexing (WDM), passive optical networks (PONs), and free-space optical (FSO) communication. This system utilizes an efficient wavelength reuse technique employing reflective semiconductor optical amplifiers (RSOAs), which helps reduce costs and boost capacity, resulting in a high-throughput network. The setup achieves a downstream data rate of 125 Gbps using 16-quadrature amplitude modulation (16-QAM) and an upstream data rate of 10 Gbps using on-off keying (OOK). An FSO link was modeled using a Gamma–Gamma channel for optical signal transmission. The bit error rate (BER) results suggest that the fronthaul based on WDM-FSO-PON can reach 4 Tbps over a 2.5 km free-space link.
{"title":"Coherent WDM-PON and free space optical (FSO) system for front-haul in next-generation cellular networks","authors":"Dokhyl AlQahtani , Fady El-Nahal","doi":"10.1016/j.ijleo.2024.172212","DOIUrl":"10.1016/j.ijleo.2024.172212","url":null,"abstract":"<div><div>The demand for optical networks that offer low latency and high capacity is increasing with the rise of next-generation cellular systems. Centralized Radio Access Network (C-RAN) architecture provides a cost-effective approach to mobile network deployment. To enhance flexibility and minimize fronthaul network implementation expenses, we propose a bidirectional fronthaul C-RAN configuration that combines coherent Wavelength Division Multiplexing (WDM), passive optical networks (PONs), and free-space optical (FSO) communication. This system utilizes an efficient wavelength reuse technique employing reflective semiconductor optical amplifiers (RSOAs), which helps reduce costs and boost capacity, resulting in a high-throughput network. The setup achieves a downstream data rate of 125 Gbps using 16-quadrature amplitude modulation (16-QAM) and an upstream data rate of 10 Gbps using on-off keying (OOK). An FSO link was modeled using a Gamma–Gamma channel for optical signal transmission. The bit error rate (BER) results suggest that the fronthaul based on WDM-FSO-PON can reach 4 Tbps over a 2.5 km free-space link.</div></div>","PeriodicalId":19513,"journal":{"name":"Optik","volume":"323 ","pages":"Article 172212"},"PeriodicalIF":3.1,"publicationDate":"2025-01-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143183008","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}
Wire ropes, as the primary load-bearing components of winch-type sluice gates, require regular maintenance to ensure proper functioning. Traditional cleaning methods for wire ropes often face some issues such as low cleaning efficiency and the risk of damaging the materials matrix the ropes. In order to address these issues of traditional cleaning methods, this paper proposed a cleaning method by employing a nanosecond pulsed fiber laser for the removal of hardened grease from the surface of wire ropes used in sluice gates. The effects of laser power, pulse width, spot overlap rate, and number of cleaning times on the grease removal effect and the degree of damage to the wire rope substrate were investigated by designing single-factor controlled variables and multifactorial orthogonal experiments. The experiment results of effectiveness of grease cleaning were quantified by using the chroma value of a grayscale image, and the degree of damage to the wire rope substrate was presented by using a scanning electron microscope and energy spectrometer to scan the rope surface before and after laser cleaning. The experimental results reveal that optimal grease removal occurs under the following conditions: laser power of 55 W, pulse width of 200 ns, spot overlap rate of 55 %, and two laser cleaning passes, which the integrity of the galvanized layer on the substrate was preserved and minimizing potential damage to the material.
{"title":"Process study of nanosecond pulsed laser cleaning of grease contamination on sluice wire rope surfaces","authors":"Daming Wu , Guisheng Fang , Wei Zhao , Yehang Pan , Taoyuan Zhang , Zhenhua Duan","doi":"10.1016/j.ijleo.2024.172199","DOIUrl":"10.1016/j.ijleo.2024.172199","url":null,"abstract":"<div><div>Wire ropes, as the primary load-bearing components of winch-type sluice gates, require regular maintenance to ensure proper functioning. Traditional cleaning methods for wire ropes often face some issues such as low cleaning efficiency and the risk of damaging the materials matrix the ropes. In order to address these issues of traditional cleaning methods, this paper proposed a cleaning method by employing a nanosecond pulsed fiber laser for the removal of hardened grease from the surface of wire ropes used in sluice gates. The effects of laser power, pulse width, spot overlap rate, and number of cleaning times on the grease removal effect and the degree of damage to the wire rope substrate were investigated by designing single-factor controlled variables and multifactorial orthogonal experiments. The experiment results of effectiveness of grease cleaning were quantified by using the chroma value of a grayscale image, and the degree of damage to the wire rope substrate was presented by using a scanning electron microscope and energy spectrometer to scan the rope surface before and after laser cleaning. The experimental results reveal that optimal grease removal occurs under the following conditions: laser power of 55 W, pulse width of 200 ns, spot overlap rate of 55 %, and two laser cleaning passes, which the integrity of the galvanized layer on the substrate was preserved and minimizing potential damage to the material.</div></div>","PeriodicalId":19513,"journal":{"name":"Optik","volume":"322 ","pages":"Article 172199"},"PeriodicalIF":3.1,"publicationDate":"2025-01-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143162236","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 : 2024-12-31DOI: 10.1016/j.ijleo.2024.172209
Razieh SoltaniSarvestani, Rahim Ghayour, Maryam Mohitpour
An infrared multi-channel optical de/multiplexer consisting of plasmonic waveguides is designed and numerically investigated. The proposed device applies the advantages of surface plasmon polaritons and the Bragg filter waveguides to realize the multi/demulti-plexing function. In this work, the application of single tuned defect in the middle of Bragg grating and a tuned nano-cavity for each channel in the proposed structures present some novel results as demultiplexers operation. According to the simulation results, the transmittances of the output channels reach up to 50 % at the desired wavelengths. Thereafter, the geometries of the proposed structures have been optimized to enhance the functional characteristics. Within the channels, a wavelength spacing of 130 nm and a crosstalk around − 22.6 dB is obtained for the optimized four-channel structure in the desired operating wavelength range. In addition to presenting an innovative structure in this article, the performance parameters such as crosstalk and transmittance are at higher levels compared to those of the devices presented in similar works. The simple fabrication process, high efficiency, narrow passband and wide operating range make the proposed micro device a suitable choice for several applications in optical telecommunications.
{"title":"Design and analysis of an optical demultiplexer based on Bragg grating using plasmonic waveguides and defects","authors":"Razieh SoltaniSarvestani, Rahim Ghayour, Maryam Mohitpour","doi":"10.1016/j.ijleo.2024.172209","DOIUrl":"10.1016/j.ijleo.2024.172209","url":null,"abstract":"<div><div>An infrared multi-channel optical de/multiplexer consisting of plasmonic waveguides is designed and numerically investigated. The proposed device applies the advantages of surface plasmon polaritons and the Bragg filter waveguides to realize the multi/demulti-plexing function. In this work, the application of single tuned defect in the middle of Bragg grating and a tuned nano-cavity for each channel in the proposed structures present some novel results as demultiplexers operation. According to the simulation results, the transmittances of the output channels reach up to 50 % at the desired wavelengths. Thereafter, the geometries of the proposed structures have been optimized to enhance the functional characteristics. Within the channels, a wavelength spacing of 130 nm and a crosstalk around − 22.6 dB is obtained for the optimized four-channel structure in the desired operating wavelength range. In addition to presenting an innovative structure in this article, the performance parameters such as crosstalk and transmittance are at higher levels compared to those of the devices presented in similar works. The simple fabrication process, high efficiency, narrow passband and wide operating range make the proposed micro device a suitable choice for several applications in optical telecommunications.</div></div>","PeriodicalId":19513,"journal":{"name":"Optik","volume":"322 ","pages":"Article 172209"},"PeriodicalIF":3.1,"publicationDate":"2024-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143162216","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 : 2024-12-31DOI: 10.1016/j.ijleo.2024.172200
Yue Feng , Haodong Wu , Mohammed Hazaea Esmail , Chi Liu , Xin Liu , Chao Wang , Tao Shen
As water pollution becomes increasingly severe, human health is facing threats from heavy metal lead ions in water. Therefore, detecting trace amounts of Pb2+ in water has become crucial. Fiber optic sensors have garnered significant attention in the sensor research field due to their small size, high sensitivity, and ease of integration. However, developing a fiber optic sensor capable of detecting Pb2+ at the pmol/L level poses a challenge. The study proposes a novel micro-nano fiber coupler cascaded tilted fiber grating (MFC-TFG) sensor, which is modified with glutathione complexed titanium carbide MXene (GSH@Ti2C) for the detection of Pb2+ concentrations in water environments. It exhibits a selective response to Pb2+ and achieves a limit of detection (LOD) of 0.624 pM (0.013 ng/dL). In the sensor structure, the cladding modes of the TFG can respond to changes in refractive index (RI) and temperature, while the core mode is only affected by temperature. Consequently, the MFC-TFG sensor can simultaneously detect environmental parameters of RI and temperature. By combining fiber optic designs and optimizing sensitive materials, the study addresses ultra-low Pb2+ detection, offering a robust fiber optic solution for heavy metal sensing.
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