We have proposed three novel Raman techniques to expand capabilities for non-destructive dyed-fiber forensics: THz Raman spectroscopy (TRS), integrating-cavity-enhanced Raman spectroscopy (ICERS), and deep-UV Raman spectroscopy (DUVRS). In this study, we report on our attempts to apply these techniques to a variety of dyed-nylon fibers and report on the results of each technique, with a particular focus on the dyes Acid Red 337 and Acid Yellow 49. We find that none of the dyes tested had discernible THz peaks but that they do impact the peak positions of the host fabric’s THz spectrum. For ICERS, we find that light absorption overwhelms any possible cavity enhancement, making the technique unusable for most dyed fabrics when using UV/VIS excitation. However, NIR excitation may still prove beneficial, but a new cavity material (with a higher NIR reflectance) is needed. Finally, we tested DUVRS but found that, for all the dyed fibers tested, the DUV excitation resulted in rapid photodegradation, making the technique unusable for non-destructive forensics.
{"title":"Comparison of Novel Raman Techniques for Fiber Forensics","authors":"Benjamin R. Anderson, N. Gese, H. Eilers","doi":"10.3390/opt4030032","DOIUrl":"https://doi.org/10.3390/opt4030032","url":null,"abstract":"We have proposed three novel Raman techniques to expand capabilities for non-destructive dyed-fiber forensics: THz Raman spectroscopy (TRS), integrating-cavity-enhanced Raman spectroscopy (ICERS), and deep-UV Raman spectroscopy (DUVRS). In this study, we report on our attempts to apply these techniques to a variety of dyed-nylon fibers and report on the results of each technique, with a particular focus on the dyes Acid Red 337 and Acid Yellow 49. We find that none of the dyes tested had discernible THz peaks but that they do impact the peak positions of the host fabric’s THz spectrum. For ICERS, we find that light absorption overwhelms any possible cavity enhancement, making the technique unusable for most dyed fabrics when using UV/VIS excitation. However, NIR excitation may still prove beneficial, but a new cavity material (with a higher NIR reflectance) is needed. Finally, we tested DUVRS but found that, for all the dyed fibers tested, the DUV excitation resulted in rapid photodegradation, making the technique unusable for non-destructive forensics.","PeriodicalId":54548,"journal":{"name":"Progress in Optics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-07-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75507863","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}
F. N. Murrieta-Rico, J. Antúnez-García, R. Yocupicio-Gaxiola, Armando Reyes Serrato, V. Petranovskii, M. Xiao, O. Sergiyenko, W. Flores-Fuentes, J. Rodríguez-Quiñonez
Zeolites are porous materials that have cavities interconnected by channels. These crystalline materials are composed of Si-O tetrahedral structures, and according to the assembly of such tetrahedral structures, specific crystalline structures are obtained. Until now, it has been said that there are more than 245 different zeolitic frameworks, and since each one has a specific distribution of pores and cavities, each kind of zeolite has a specific area-to-volume ratio. As a result of the type of zeolite structure, the zeolite can exhibit specific properties, i.e., electrical or optical. Moreover, the physical properties of zeolites can be modified after the inclusion of another chemical species in their structure or in their voids, which can result in tuning a zeolite for specific applications. In this work, synthetic zeolites of types LTA, FAU and MFI are characterized by a number of methods. In particular, the data from UV-Vis spectroscopy are analyzed, and the effect of crystalline structure on properties such as optical bandgap, refractive index, absorption coefficient, incident photon frequency, and extinction coefficient is studied.
{"title":"Frequency Response Analysis of FAU, LTA and MFI Zeolites Using UV-Vis and Electrochemical Impedance Spectroscopy","authors":"F. N. Murrieta-Rico, J. Antúnez-García, R. Yocupicio-Gaxiola, Armando Reyes Serrato, V. Petranovskii, M. Xiao, O. Sergiyenko, W. Flores-Fuentes, J. Rodríguez-Quiñonez","doi":"10.3390/opt4030033","DOIUrl":"https://doi.org/10.3390/opt4030033","url":null,"abstract":"Zeolites are porous materials that have cavities interconnected by channels. These crystalline materials are composed of Si-O tetrahedral structures, and according to the assembly of such tetrahedral structures, specific crystalline structures are obtained. Until now, it has been said that there are more than 245 different zeolitic frameworks, and since each one has a specific distribution of pores and cavities, each kind of zeolite has a specific area-to-volume ratio. As a result of the type of zeolite structure, the zeolite can exhibit specific properties, i.e., electrical or optical. Moreover, the physical properties of zeolites can be modified after the inclusion of another chemical species in their structure or in their voids, which can result in tuning a zeolite for specific applications. In this work, synthetic zeolites of types LTA, FAU and MFI are characterized by a number of methods. In particular, the data from UV-Vis spectroscopy are analyzed, and the effect of crystalline structure on properties such as optical bandgap, refractive index, absorption coefficient, incident photon frequency, and extinction coefficient is studied.","PeriodicalId":54548,"journal":{"name":"Progress in Optics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-07-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79799752","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}
Hyoung-In Lee, Tanvi P. Vaidya, Ram Prakash Dwivedi
A review is provided here about the thermal effects on optical chirality. To this goal, chiral objects dispersed in an embedding fluid are examined for their magnetoelectric coupling. Thermal effects on several chiral meta-atoms and their ensembles are examined. To this goal, DNA-like helical structures are examined in detail. The mechanical aspect of thermo-elasticity is reviewed along with transverse deformations while drawing analogies from condensed-matter physics. In this respect, the chirality-induced spin selection is reviewed along with the temperature-mediated electron–phonon interactions. A wide range of materials, such as polymers and biological cells, are also examined for temperature effects. A transition temperature delineating a sign flip in the chirality parameter is identified as well. Chirality-associated functionalities such as ratchet motions, switching, and modulations are investigated for their respective thermal effects. Issues of fabricating chiral meta-atoms are also discussed.
{"title":"Thermal Effects on Optical Chirality, Mechanics, and Associated Symmetry Properties","authors":"Hyoung-In Lee, Tanvi P. Vaidya, Ram Prakash Dwivedi","doi":"10.3390/opt4030030","DOIUrl":"https://doi.org/10.3390/opt4030030","url":null,"abstract":"A review is provided here about the thermal effects on optical chirality. To this goal, chiral objects dispersed in an embedding fluid are examined for their magnetoelectric coupling. Thermal effects on several chiral meta-atoms and their ensembles are examined. To this goal, DNA-like helical structures are examined in detail. The mechanical aspect of thermo-elasticity is reviewed along with transverse deformations while drawing analogies from condensed-matter physics. In this respect, the chirality-induced spin selection is reviewed along with the temperature-mediated electron–phonon interactions. A wide range of materials, such as polymers and biological cells, are also examined for temperature effects. A transition temperature delineating a sign flip in the chirality parameter is identified as well. Chirality-associated functionalities such as ratchet motions, switching, and modulations are investigated for their respective thermal effects. Issues of fabricating chiral meta-atoms are also discussed.","PeriodicalId":54548,"journal":{"name":"Progress in Optics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79611732","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}
Umberto Camellin, F. Franchina, A. Meduri, P. Aragona
Background: Intra-Ocular Lens (IOL) power calculation in long eyes remains challenging despite the availability of new formulas and biometers. This case report shows that optimization of the A-constant in the first eye can reduce postoperative refractive error in the second eye, even in the case of an IOL with negative power. This report aimed to describe a case in which this method was used to calculate IOL power to reduce postoperative refractive error in a long fellow eye. As far as we know, this is the first paper reporting the use of the optimized constant in the first eye to reduce postoperative error in the second eye in the case of a negative IOL. Case presentation: A highly myopic patient with nuclear cataracts underwent phacoemulsification cataract surgery (PCS) in both eyes. The axial length (AL) was 39.42 mm in the right eye and 37.45 mm in the left eye. All biometric data were obtained via low-coherence reflectometry using an OA-2000 biometer (Tomey, Nagoya, Japan). First, an IOL power calculation using the Barrett II formula and PCS was performed in the shorter eye. To evaluate the postoperative refractive error, the optimized A-constant in the left eye was estimated using the Camellin-Calossi formula. The new A-constant was then used for the right eye IOL power calculation using the same formula. The prediction error (PE) in the left eye was −0.23 D with the Barrett II formula. The optimized A-constant method using the Camellin-Calossi formula in the fellow eye gave −0.28 D of PE. Conclusions: The A-constant optimization for very long eyes, using data from the first operated eye, may be useful to reduce refractive prediction error in the second eye in very long eyes, as well as in the case of IOL power with negative values.
{"title":"IOL Power Calculation in an Unusual Long Fellow Eye: A Case Report","authors":"Umberto Camellin, F. Franchina, A. Meduri, P. Aragona","doi":"10.3390/opt4030029","DOIUrl":"https://doi.org/10.3390/opt4030029","url":null,"abstract":"Background: Intra-Ocular Lens (IOL) power calculation in long eyes remains challenging despite the availability of new formulas and biometers. This case report shows that optimization of the A-constant in the first eye can reduce postoperative refractive error in the second eye, even in the case of an IOL with negative power. This report aimed to describe a case in which this method was used to calculate IOL power to reduce postoperative refractive error in a long fellow eye. As far as we know, this is the first paper reporting the use of the optimized constant in the first eye to reduce postoperative error in the second eye in the case of a negative IOL. Case presentation: A highly myopic patient with nuclear cataracts underwent phacoemulsification cataract surgery (PCS) in both eyes. The axial length (AL) was 39.42 mm in the right eye and 37.45 mm in the left eye. All biometric data were obtained via low-coherence reflectometry using an OA-2000 biometer (Tomey, Nagoya, Japan). First, an IOL power calculation using the Barrett II formula and PCS was performed in the shorter eye. To evaluate the postoperative refractive error, the optimized A-constant in the left eye was estimated using the Camellin-Calossi formula. The new A-constant was then used for the right eye IOL power calculation using the same formula. The prediction error (PE) in the left eye was −0.23 D with the Barrett II formula. The optimized A-constant method using the Camellin-Calossi formula in the fellow eye gave −0.28 D of PE. Conclusions: The A-constant optimization for very long eyes, using data from the first operated eye, may be useful to reduce refractive prediction error in the second eye in very long eyes, as well as in the case of IOL power with negative values.","PeriodicalId":54548,"journal":{"name":"Progress in Optics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87440712","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}
We model the effects of the photosensitive parameters of aerosols on their optical properties to provide a solid framework for further experimental and theoretical studies. A spherical dust particle is used to study the effects of the ambient medium, size, surface roughness, wavelength, and imaginary part of the complex refractive index. Five Gaussian random spheres with different aspect ratios are simulated to study the dependence of aerosol light scattering properties on particle shape distribution. To investigate the influence of composition, we model two typical kaolinite-like particles (pure and composite) collected from Southwest Sahara, with 0 and 2% hematite at different mixing states. Using the method of discrete-dipole approximation in DDSCAT, a comparative study is performed with the Mueller matrix elements, scattering, absorption, extinction efficiencies, single scattering albedo, and linear depolarization ratio as indicators. For single, microscopic dust particles, near-field calculations are carried out. The results show that the intensity of backscattering and the scattering efficiency decreases in water compared to dry air. Light in the visible range is more efficient for aerosol scattering experiments. A small number of impurities in the sample will increase its absorbing properties, but, in general, the scattering efficiencies strongly depend on the single-particle mixing state. Smaller particles with a diameter comparable to the wavelength of incident light show higher scattering efficiencies but lower backscattering intensities than larger particles, while surface roughness is shown to strongly alter the polarizability of the particle but has a negligible effect on its single-scattering albedo. Moreover, different shapes have a strong effect on the degree of linear polarization, but, in general, using the spherical over elliptic shape model can underestimate the scattering efficiencies by up to 4%. Finally, variation in the imaginary part of the complex RI can underestimate the single scattering albedo by up to 35.8%.
{"title":"Near-Field Single-Scattering Calculations of Aerosols: Sensitivity Studies","authors":"N. A. Arreyndip, K. Kandler, Aryasree Sudharaj","doi":"10.3390/opt4020028","DOIUrl":"https://doi.org/10.3390/opt4020028","url":null,"abstract":"We model the effects of the photosensitive parameters of aerosols on their optical properties to provide a solid framework for further experimental and theoretical studies. A spherical dust particle is used to study the effects of the ambient medium, size, surface roughness, wavelength, and imaginary part of the complex refractive index. Five Gaussian random spheres with different aspect ratios are simulated to study the dependence of aerosol light scattering properties on particle shape distribution. To investigate the influence of composition, we model two typical kaolinite-like particles (pure and composite) collected from Southwest Sahara, with 0 and 2% hematite at different mixing states. Using the method of discrete-dipole approximation in DDSCAT, a comparative study is performed with the Mueller matrix elements, scattering, absorption, extinction efficiencies, single scattering albedo, and linear depolarization ratio as indicators. For single, microscopic dust particles, near-field calculations are carried out. The results show that the intensity of backscattering and the scattering efficiency decreases in water compared to dry air. Light in the visible range is more efficient for aerosol scattering experiments. A small number of impurities in the sample will increase its absorbing properties, but, in general, the scattering efficiencies strongly depend on the single-particle mixing state. Smaller particles with a diameter comparable to the wavelength of incident light show higher scattering efficiencies but lower backscattering intensities than larger particles, while surface roughness is shown to strongly alter the polarizability of the particle but has a negligible effect on its single-scattering albedo. Moreover, different shapes have a strong effect on the degree of linear polarization, but, in general, using the spherical over elliptic shape model can underestimate the scattering efficiencies by up to 4%. Finally, variation in the imaginary part of the complex RI can underestimate the single scattering albedo by up to 35.8%.","PeriodicalId":54548,"journal":{"name":"Progress in Optics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-06-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80518247","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}
Image-guided liver biopsies can improve their success rate when combined with the optical detection of Indocyanine Green (ICG) fluorescence accumulated in tumors. Previous works used a camera coupled to a thin borescope to capture and quantify images from fluorescence emission during procedures; however, light-scattering prevented the formation of sharp images, and the time response for weakly fluorescent tumors was very low. Instead, replacing the camera with a photodiode detector shows an improved temporal resolution in a more compact and lighter device. This work presents the new design in a comparative study between both detection technologies, including an assessment of the temporal response and sensitivity to the presence of background fluorescence.
{"title":"Advantages of a Photodiode Detector Endoscopy System in Fluorescence-Guided Percutaneous Liver Biopsies.","authors":"Asier Marcos-Vidal, Pedram Heidari, Sheng Xu, Bradford J Wood, Umar Mahmood","doi":"10.3390/opt4020025","DOIUrl":"10.3390/opt4020025","url":null,"abstract":"<p><p>Image-guided liver biopsies can improve their success rate when combined with the optical detection of Indocyanine Green (ICG) fluorescence accumulated in tumors. Previous works used a camera coupled to a thin borescope to capture and quantify images from fluorescence emission during procedures; however, light-scattering prevented the formation of sharp images, and the time response for weakly fluorescent tumors was very low. Instead, replacing the camera with a photodiode detector shows an improved temporal resolution in a more compact and lighter device. This work presents the new design in a comparative study between both detection technologies, including an assessment of the temporal response and sensitivity to the presence of background fluorescence.</p>","PeriodicalId":54548,"journal":{"name":"Progress in Optics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10701657/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79419624","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The impact of intraocular scatter and higher order aberrations (HOAs) on ocular optical quality was investigated. An optical eye model was constructed using the measured ocular aberrations, corneal surfaces, axial length, and scatter fraction, and the impact of HOAs and scatter on modulation transfer functions (MTFs) was studied based on the newly established optical eye model. For uniform intraocular scatter, the monochromatic and polychromatic MTF decreased as the HOAs or scatter fractions increased independently at each spatial frequency, which implied that both were essential for visual quality. In addition, the scatter effect on MTF was more significant for the eye with less HOA. The combined deterioration effect of these two factors on the MTF was less than their summation, suggesting a potential compensatory mechanism between HOAs and scatter.
{"title":"Effect of Higher Order Aberrations and Intraocular Scatter on Optical Quality Based on an Optical Eye Model","authors":"Feng Rao, X. Zhao, Ming Zhang, Yan Wang","doi":"10.3390/opt4020027","DOIUrl":"https://doi.org/10.3390/opt4020027","url":null,"abstract":"The impact of intraocular scatter and higher order aberrations (HOAs) on ocular optical quality was investigated. An optical eye model was constructed using the measured ocular aberrations, corneal surfaces, axial length, and scatter fraction, and the impact of HOAs and scatter on modulation transfer functions (MTFs) was studied based on the newly established optical eye model. For uniform intraocular scatter, the monochromatic and polychromatic MTF decreased as the HOAs or scatter fractions increased independently at each spatial frequency, which implied that both were essential for visual quality. In addition, the scatter effect on MTF was more significant for the eye with less HOA. The combined deterioration effect of these two factors on the MTF was less than their summation, suggesting a potential compensatory mechanism between HOAs and scatter.","PeriodicalId":54548,"journal":{"name":"Progress in Optics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-05-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82272591","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}
Sheheera Irfan, Yasir A. Haleem, M. Irshad, Muhammad Farooq Saleem, M. Arshad, Muhammad Habib
Phase transitions are an intriguing yet poorly understood aspect of transition-metal-based materials; these phase transitions can result in changes to the refractive index, absorption coefficient, and other optical properties of the materials. Transition-metal-based materials exist in a variety of crystalline phases and also have metallic, semi-metallic, and semi-conducting characteristics. In this review, we demonstrate that alloyed W- and Mo-based dichalcogenides enable phase transitions in structures, with phase transition temperatures that are tunable across a wide range using various alloy models and modern DFT-based calculations. We also analyze the tuning the optical bandgap of the metal oxide nanoparticles through doping of the transition metal in a manner that is suitable for optical switching and thermal imaging. After the introduction and a brief illustration of the structures and their exceptional properties, we discuss synthetic methodologies and their application as part of important strategies toward the enhanced performance of transition-metal-based dichalcogenides and oxides. In the end, our conclusion highlights the prospects of 2D materials as phase transition materials due to their advantages in terms of scalability and adaptability.
{"title":"Tunability of the Optical Properties of Transition-Metal-Based Structural Phase Change Materials","authors":"Sheheera Irfan, Yasir A. Haleem, M. Irshad, Muhammad Farooq Saleem, M. Arshad, Muhammad Habib","doi":"10.3390/opt4020026","DOIUrl":"https://doi.org/10.3390/opt4020026","url":null,"abstract":"Phase transitions are an intriguing yet poorly understood aspect of transition-metal-based materials; these phase transitions can result in changes to the refractive index, absorption coefficient, and other optical properties of the materials. Transition-metal-based materials exist in a variety of crystalline phases and also have metallic, semi-metallic, and semi-conducting characteristics. In this review, we demonstrate that alloyed W- and Mo-based dichalcogenides enable phase transitions in structures, with phase transition temperatures that are tunable across a wide range using various alloy models and modern DFT-based calculations. We also analyze the tuning the optical bandgap of the metal oxide nanoparticles through doping of the transition metal in a manner that is suitable for optical switching and thermal imaging. After the introduction and a brief illustration of the structures and their exceptional properties, we discuss synthetic methodologies and their application as part of important strategies toward the enhanced performance of transition-metal-based dichalcogenides and oxides. In the end, our conclusion highlights the prospects of 2D materials as phase transition materials due to their advantages in terms of scalability and adaptability.","PeriodicalId":54548,"journal":{"name":"Progress in Optics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-05-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78329979","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}
Ben Sicks, Anna-Maria Gierke, Florian Sommerfeld, Martin Klein, M. Hessling
(1) Background: Applications using touch screens are increasingly deployed in medical facilities, as well as in public areas. When touching the display with fingers, potentially pathogenic microorganisms such as methicillin-resistant Staphylococcus aureus (MRSA) can be transmitted. An automated process to decontaminate the device in between users would be highly useful. (2) Methods: Thin glass plates were superficially contaminated with the non-pathogenic Staphylococcus carnosus in a controlled manner. Subsequently, UVA radiation of 400 or 380 nm was laterally coupled into the glass plate, which acted as a light guide. Contact agar plates recorded the change in the staphylococci concentration over time. Additionally, the UVA radiation emitted by the glass plates was measured and the potential risk to humans assessed. (3) Results: Staphylococci concentration decreased as a result of UVA radiation for both wavelengths. At 400 nm, it took about 7.5 h and at 380 nm about 1 h until a reduction of 90% was reached. To meet higher disinfection requirements, disproportionately longer irradiation times were necessary. The potential UVA irradiation of humans in front of the glass pane was about 35 µW/cm2 or less and posed no risk to humans. (4) Conclusions: Side-coupled UVA radiation is in principle capable of safely automatically disinfecting microorganisms on touch screens. However, the required irradiation times are still in the hour range, so that a rapid disinfection within a minute or less is not yet possible with the presented setup. However, higher UVA intensities might reduce the current disinfection durations.
{"title":"Disinfection of Transparent Screens by Side-Coupled UVA LED Radiation","authors":"Ben Sicks, Anna-Maria Gierke, Florian Sommerfeld, Martin Klein, M. Hessling","doi":"10.3390/opt4020023","DOIUrl":"https://doi.org/10.3390/opt4020023","url":null,"abstract":"(1) Background: Applications using touch screens are increasingly deployed in medical facilities, as well as in public areas. When touching the display with fingers, potentially pathogenic microorganisms such as methicillin-resistant Staphylococcus aureus (MRSA) can be transmitted. An automated process to decontaminate the device in between users would be highly useful. (2) Methods: Thin glass plates were superficially contaminated with the non-pathogenic Staphylococcus carnosus in a controlled manner. Subsequently, UVA radiation of 400 or 380 nm was laterally coupled into the glass plate, which acted as a light guide. Contact agar plates recorded the change in the staphylococci concentration over time. Additionally, the UVA radiation emitted by the glass plates was measured and the potential risk to humans assessed. (3) Results: Staphylococci concentration decreased as a result of UVA radiation for both wavelengths. At 400 nm, it took about 7.5 h and at 380 nm about 1 h until a reduction of 90% was reached. To meet higher disinfection requirements, disproportionately longer irradiation times were necessary. The potential UVA irradiation of humans in front of the glass pane was about 35 µW/cm2 or less and posed no risk to humans. (4) Conclusions: Side-coupled UVA radiation is in principle capable of safely automatically disinfecting microorganisms on touch screens. However, the required irradiation times are still in the hour range, so that a rapid disinfection within a minute or less is not yet possible with the presented setup. However, higher UVA intensities might reduce the current disinfection durations.","PeriodicalId":54548,"journal":{"name":"Progress in Optics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82633839","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}
Nuisance alarm rate (NAR) is one of the key performance parameters in a phase-sensitive optical time domain reflectometry (φ-OTDR)-based fence intrusion detection system. Typically, the vibrations caused by ambient environmental conditions, such as heavy rain, strong wind, and passing vehicles, easily result in many nuisance alarms. Significant research efforts have been undertaken to suppress the NAR. In this paper, we propose to utilize short segments of the sensing fiber as reference sensors for significant reduction in the NAR in φ-OTDR for the first time, to the best of our knowledge. According to our field trial results, the proposed approach can reduce the NAR by more than 90%. The proposed approach is very simple, practical, and cost-effective, which can be easily integrated with the existing methods of reducing NAR and act as an additional level of decision-making algorithm for triggering alarms.
{"title":"Self-Contained Reference Sensors to Reduce Nuisance Alarm Rate in φ-OTDR-Based Fence Intrusion Detection System","authors":"Hailiang Zhang, Hui Dong, D. Hu, Jun Hong Ng","doi":"10.3390/opt4020024","DOIUrl":"https://doi.org/10.3390/opt4020024","url":null,"abstract":"Nuisance alarm rate (NAR) is one of the key performance parameters in a phase-sensitive optical time domain reflectometry (φ-OTDR)-based fence intrusion detection system. Typically, the vibrations caused by ambient environmental conditions, such as heavy rain, strong wind, and passing vehicles, easily result in many nuisance alarms. Significant research efforts have been undertaken to suppress the NAR. In this paper, we propose to utilize short segments of the sensing fiber as reference sensors for significant reduction in the NAR in φ-OTDR for the first time, to the best of our knowledge. According to our field trial results, the proposed approach can reduce the NAR by more than 90%. The proposed approach is very simple, practical, and cost-effective, which can be easily integrated with the existing methods of reducing NAR and act as an additional level of decision-making algorithm for triggering alarms.","PeriodicalId":54548,"journal":{"name":"Progress in Optics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86345992","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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