G. Veronis, Yin Huang, Yuecheng Shen, Vahid Foroughi Nezhad, Chenglong You
We introduce a nanoplasmonic isolator consisting of a cavity coupled to a metal-dielectric-metal (MDM) waveguide. The waveguide and cavity are filled with a magneto-optical (MO) material, and the structure is under a static magnetic field. We show that, when MO activity is present, the cavity becomes a traveling wave resonator with unequal decay rates into the forward and backward directions. As a result, the structure operates as an isolator. We also introduce non-Hermitian plasmonic waveguide-cavity systems with topological edge states (TESs) at singular points. The structure unit cells consist of an MDM waveguide side-coupled to MDM stub resonators with modulated distances between adjacent stubs. In such structures the modulated distances introduce an effective gauge magnetic field. We show that such structures achieve extremely high sensitivity of the reflected light intensity. TESs at singular points could lead to singularity-based plasmonic devices with enhanced performance.
{"title":"Magneto-optical isolation and topological edge states at singular points in plasmonic structures","authors":"G. Veronis, Yin Huang, Yuecheng Shen, Vahid Foroughi Nezhad, Chenglong You","doi":"10.1117/12.2633235","DOIUrl":"https://doi.org/10.1117/12.2633235","url":null,"abstract":"We introduce a nanoplasmonic isolator consisting of a cavity coupled to a metal-dielectric-metal (MDM) waveguide. The waveguide and cavity are filled with a magneto-optical (MO) material, and the structure is under a static magnetic field. We show that, when MO activity is present, the cavity becomes a traveling wave resonator with unequal decay rates into the forward and backward directions. As a result, the structure operates as an isolator. We also introduce non-Hermitian plasmonic waveguide-cavity systems with topological edge states (TESs) at singular points. The structure unit cells consist of an MDM waveguide side-coupled to MDM stub resonators with modulated distances between adjacent stubs. In such structures the modulated distances introduce an effective gauge magnetic field. We show that such structures achieve extremely high sensitivity of the reflected light intensity. TESs at singular points could lead to singularity-based plasmonic devices with enhanced performance.","PeriodicalId":13820,"journal":{"name":"International Conference on Nanoscience, Engineering and Technology (ICONSET 2011)","volume":"23 1","pages":"121960C - 121960C-6"},"PeriodicalIF":0.0,"publicationDate":"2022-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74293787","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}
Agnès Pérez-Millan, Laia Borrell, José Contador, M. Balasa, A. Lladó, R. Sánchez-Valle, R. Sala‐Llonch
INTRODUCTION: Early Onset Alzheimer’s Disease (EOAD, <65 years) and Frontotemporal Dementia (FTD) are common forms of early-onset dementia. Therefore, there is a need to establish accurate diagnosis and to obtain markers for disease tracking. We combined supervised and unsupervised machine learning (ML) to discriminate between EOAD and FTD patients. METHODS: We included 3T-T1 MRI of 203 subjects under 65 years old: 66 healthy controls (CTR, age: 55.0 ± 8.4 years), 85 EOAD patients (age: 57.3 ± 6.1 years) and 52 FTD patients (age: 57.9 ± 4.8 years). We obtained subcortical gray matter volumes and cortical thickness (CTh) regional measures using FreeSurfer. For ML, we performed a Principal Component Analysis (PCA) of all volumes and CTh values. Then, the first principal component (PC) was introduced into a Support Vector Machine (SVM). Overall performance was assessed using k-fold cross-validation. RESULTS: Our algorithm had an accuracy of 87.2 ± 14.2 % in the CTR vs EOAD classification, 80.8 ± 20.4% for CTR vs FTD, 66.5 ± 12.9 % for EOAD vs FTD and 65.2 ± 10.6% when discriminating the three groups. We used the weights of the first PC to create disease-specific patterns. CONCLUSION: By using a single feature that combines information from CTh and subcortical volumes, our algorithm classifies CTR, EOAD and FTD with good accuracy. We suggest that this approach can be used as a feature reduction strategy in ML algorithms while providing interpretable atrophy patterns.
{"title":"Classification between early onset Alzheimer's disease and frontotemporal dementia using a single neuroimaging feature","authors":"Agnès Pérez-Millan, Laia Borrell, José Contador, M. Balasa, A. Lladó, R. Sánchez-Valle, R. Sala‐Llonch","doi":"10.1117/12.2632990","DOIUrl":"https://doi.org/10.1117/12.2632990","url":null,"abstract":"INTRODUCTION: Early Onset Alzheimer’s Disease (EOAD, <65 years) and Frontotemporal Dementia (FTD) are common forms of early-onset dementia. Therefore, there is a need to establish accurate diagnosis and to obtain markers for disease tracking. We combined supervised and unsupervised machine learning (ML) to discriminate between EOAD and FTD patients. METHODS: We included 3T-T1 MRI of 203 subjects under 65 years old: 66 healthy controls (CTR, age: 55.0 ± 8.4 years), 85 EOAD patients (age: 57.3 ± 6.1 years) and 52 FTD patients (age: 57.9 ± 4.8 years). We obtained subcortical gray matter volumes and cortical thickness (CTh) regional measures using FreeSurfer. For ML, we performed a Principal Component Analysis (PCA) of all volumes and CTh values. Then, the first principal component (PC) was introduced into a Support Vector Machine (SVM). Overall performance was assessed using k-fold cross-validation. RESULTS: Our algorithm had an accuracy of 87.2 ± 14.2 % in the CTR vs EOAD classification, 80.8 ± 20.4% for CTR vs FTD, 66.5 ± 12.9 % for EOAD vs FTD and 65.2 ± 10.6% when discriminating the three groups. We used the weights of the first PC to create disease-specific patterns. CONCLUSION: By using a single feature that combines information from CTh and subcortical volumes, our algorithm classifies CTR, EOAD and FTD with good accuracy. We suggest that this approach can be used as a feature reduction strategy in ML algorithms while providing interpretable atrophy patterns.","PeriodicalId":13820,"journal":{"name":"International Conference on Nanoscience, Engineering and Technology (ICONSET 2011)","volume":"71 1","pages":"122040D - 122040D-8"},"PeriodicalIF":0.0,"publicationDate":"2022-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84139284","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, we demonstrate the approach of obtaining an array of ZnO nanowires, deposited as a thin film on different substrates (glass, Si plate, foil, etc.). As-obtained ZnO thin films have a hydrophilic state with water droplets with a contact angle value of 0°. Treatment of ZnO thin films with H2 gas (under specific conditions) changes the state of ZnO thin films to a hydrophobic state with a roll-off angle with the droplet of water 60°. However, ZnO thin films treatment with O2 gas makes ZnO thin films go back to a hydrophilic state. This operation can be repeated in a cycle manner using H2 and O2 gases to approach different states of ZnO thin films such as hydrophilic and hydrophobic. Thin films of ZnO nanowires can be deposited on a variety of substrates such as glasses, metals, and polyamides.
{"title":"A method for modifying the surface properties of ZnO nanowires deposited as thin films on various substrates","authors":"V. Kolbjonoks, Vladimirs Kostjukevičs","doi":"10.1117/12.2633401","DOIUrl":"https://doi.org/10.1117/12.2633401","url":null,"abstract":"In this paper, we demonstrate the approach of obtaining an array of ZnO nanowires, deposited as a thin film on different substrates (glass, Si plate, foil, etc.). As-obtained ZnO thin films have a hydrophilic state with water droplets with a contact angle value of 0°. Treatment of ZnO thin films with H2 gas (under specific conditions) changes the state of ZnO thin films to a hydrophobic state with a roll-off angle with the droplet of water 60°. However, ZnO thin films treatment with O2 gas makes ZnO thin films go back to a hydrophilic state. This operation can be repeated in a cycle manner using H2 and O2 gases to approach different states of ZnO thin films such as hydrophilic and hydrophobic. Thin films of ZnO nanowires can be deposited on a variety of substrates such as glasses, metals, and polyamides.","PeriodicalId":13820,"journal":{"name":"International Conference on Nanoscience, Engineering and Technology (ICONSET 2011)","volume":"79 1","pages":"122020C - 122020C-6"},"PeriodicalIF":0.0,"publicationDate":"2022-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91231494","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}
M. Serhatlioglu, Emil Alstrup Jensen, M. Niora, A. T. Hansen, Christian Friberg Nielsen, Michelle Maria Theresia Jansman, L. Hosta‐Rigau, M. Dziegiel, K. Berg-Sørensen, I. Hickson, A. Kristensen
Flow cytometry (FC) is a pivotal tool for studying the physical and chemical properties of particles. State-of-the-art FC systems are highly advanced, yet they are expensive, bulky, and require high sample volume, qualified operators, and periodic maintenance. The manipulation of particles suspended in viscoelastic fluids has received increasing attention, especially for miniaturized flow cytometry technologies. This study presents a miniaturized optical capillary FC device using the viscoelastic focusing technique. A straight, one inlet/outlet microcapillary device is precisely aligned to a fiber-coupled laser source and detectors. Forward scattered, side scattered, and fluorescently emitted light signals are collected and analyzed in a real-time environment. The developed platform fits onto an inverted microscope stage enabling real-time microscopy imaging of the particles of interest together with the flow cytometry analysis. We achieved stable viscoelastic focusing and performed FC measurements for rigid polystyrene beads (diameters: 2 – 15 μm), non-spherical human erythrocytes, and canonical shape metaphase human chromosomes. We performed cytometry measurements with a throughput of 100 events/s yielding a coefficient of variation of 2%. This newly developed FC device is a versatile tool and can be operated with any inverted microscope to get the mutual benefits of optical and imaging FC measurements. Furthermore, it is possible to extend these benefits by adding more back-end tools, such as optical trapping and Raman spectroscopy.
{"title":"Development of a fiber-based microfluidic flow cytometry platform using viscoelastic fluids for polydisperse particle suspensions","authors":"M. Serhatlioglu, Emil Alstrup Jensen, M. Niora, A. T. Hansen, Christian Friberg Nielsen, Michelle Maria Theresia Jansman, L. Hosta‐Rigau, M. Dziegiel, K. Berg-Sørensen, I. Hickson, A. Kristensen","doi":"10.1117/12.2633628","DOIUrl":"https://doi.org/10.1117/12.2633628","url":null,"abstract":"Flow cytometry (FC) is a pivotal tool for studying the physical and chemical properties of particles. State-of-the-art FC systems are highly advanced, yet they are expensive, bulky, and require high sample volume, qualified operators, and periodic maintenance. The manipulation of particles suspended in viscoelastic fluids has received increasing attention, especially for miniaturized flow cytometry technologies. This study presents a miniaturized optical capillary FC device using the viscoelastic focusing technique. A straight, one inlet/outlet microcapillary device is precisely aligned to a fiber-coupled laser source and detectors. Forward scattered, side scattered, and fluorescently emitted light signals are collected and analyzed in a real-time environment. The developed platform fits onto an inverted microscope stage enabling real-time microscopy imaging of the particles of interest together with the flow cytometry analysis. We achieved stable viscoelastic focusing and performed FC measurements for rigid polystyrene beads (diameters: 2 – 15 μm), non-spherical human erythrocytes, and canonical shape metaphase human chromosomes. We performed cytometry measurements with a throughput of 100 events/s yielding a coefficient of variation of 2%. This newly developed FC device is a versatile tool and can be operated with any inverted microscope to get the mutual benefits of optical and imaging FC measurements. Furthermore, it is possible to extend these benefits by adding more back-end tools, such as optical trapping and Raman spectroscopy.","PeriodicalId":13820,"journal":{"name":"International Conference on Nanoscience, Engineering and Technology (ICONSET 2011)","volume":"24 1","pages":"1219802 - 1219802-8"},"PeriodicalIF":0.0,"publicationDate":"2022-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78447556","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}
G. Hunt, J. Miragliotta, L. Oh, J. Ginn, A. Warren, D. Shrekenhamer
Thermal regulation is essential for numerous applications across multiple industries such as the efficient temperature control of indoor facilities and the reliable operation of many electronic systems. Vanadium dioxide (VO2) is a phase change material that is well-suited for thermal regulation as a result of its ultrafast, reversible, solid-state transition at 68°C that produces a significant contrast in its infrared (IR) emissive properties. To meet application demands, VO2’s transition temperature can be tuned via doping with a reduction in temperature of ~22 °C per atomic percent tungsten (at. % W6+). However, historically this decrease in the transition temperature has coincided with a reduction in IR optical contrast between the two phases. In this investigation, we demonstrate that by patterning VO2 thin film composites with preoptimized thicknesses, a thermal regulation system with a tunable transition temperature and no significant degradation of contrast between the states is produced. Through carefully selected user-defined patterning of the undoped VO2 layer within the multilayer film, a 64% operating optical contrast was achieved across the 8 – 13 μm spectral region as compared to 42% in the as-deposited film. Additionally, at a doping level of 1.7%, the transition temperature in a VO2 thin film composite with micron-scaled patterning was reduced to 25°C while maintaining 58% emissive contrast in the 8 – 13 μm spectral region.
{"title":"High emissive contrast of patterned tungsten-doped VO2 thin film composites","authors":"G. Hunt, J. Miragliotta, L. Oh, J. Ginn, A. Warren, D. Shrekenhamer","doi":"10.1117/12.2632385","DOIUrl":"https://doi.org/10.1117/12.2632385","url":null,"abstract":"Thermal regulation is essential for numerous applications across multiple industries such as the efficient temperature control of indoor facilities and the reliable operation of many electronic systems. Vanadium dioxide (VO2) is a phase change material that is well-suited for thermal regulation as a result of its ultrafast, reversible, solid-state transition at 68°C that produces a significant contrast in its infrared (IR) emissive properties. To meet application demands, VO2’s transition temperature can be tuned via doping with a reduction in temperature of ~22 °C per atomic percent tungsten (at. % W6+). However, historically this decrease in the transition temperature has coincided with a reduction in IR optical contrast between the two phases. In this investigation, we demonstrate that by patterning VO2 thin film composites with preoptimized thicknesses, a thermal regulation system with a tunable transition temperature and no significant degradation of contrast between the states is produced. Through carefully selected user-defined patterning of the undoped VO2 layer within the multilayer film, a 64% operating optical contrast was achieved across the 8 – 13 μm spectral region as compared to 42% in the as-deposited film. Additionally, at a doping level of 1.7%, the transition temperature in a VO2 thin film composite with micron-scaled patterning was reduced to 25°C while maintaining 58% emissive contrast in the 8 – 13 μm spectral region.","PeriodicalId":13820,"journal":{"name":"International Conference on Nanoscience, Engineering and Technology (ICONSET 2011)","volume":"21 1","pages":"1219505 - 1219505-6"},"PeriodicalIF":0.0,"publicationDate":"2022-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82818603","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}
Silicon photonics has emerged as the dominant technology platform for short distance, inter-chip communication for a variety of photonic computing and sensing applications due to its efficiency in modulation and confinement of light across telecom frequencies in addition to its inherent CMOS compatibility. The integration of metallic nanogaps within silicon photonic architectures provides a promising route for scaling this platform through the extreme confinement offered by plasmonics while providing an efficient route to interfacing future photonic integrated circuits with electronics. However, fabricating the gap sizes (< λg/10) required of plasmonic resonating nanogaps for efficient operation across telecommunication frequencies is highly challenging. Efficient coupling from waveguides to plasmonic nanogaps also remains a major source of loss. Here, we show that the key to merging these platforms lies in applying metamaterial/metasurface engineering principles to the design of the nanogap. Over the last decade, metamaterials and metasurfaces have emerged as a versatile toolkit for control and enhancement of light-matter interaction at application-driven wavelengths of interest in nanophotonic device platforms. We show that integrating a metagrating within a waveguide-coupled plasmonic nanogap made from Au, can enhance coupling to and from the silicon waveguides. Furthermore, the incorporation of the metasurface within the gap allows resonant response to be maintained at user-specified wavelength of interest with gaps as large as λg/5, drastically easing fabrication. Finally, we show that by incorporating a reconfigurable phase change chalcogenide alloy into the gap, non-volatile signal switching with modulation contrasts of up to 10:1 can be achieved across telecom frequencies.
{"title":"Waveguide-coupled plasmonic nanogap-integrated phase change metasurfaces","authors":"Ahmed H. Elfarash, A. Mandal, B. Gholipour","doi":"10.1117/12.2633266","DOIUrl":"https://doi.org/10.1117/12.2633266","url":null,"abstract":"Silicon photonics has emerged as the dominant technology platform for short distance, inter-chip communication for a variety of photonic computing and sensing applications due to its efficiency in modulation and confinement of light across telecom frequencies in addition to its inherent CMOS compatibility. The integration of metallic nanogaps within silicon photonic architectures provides a promising route for scaling this platform through the extreme confinement offered by plasmonics while providing an efficient route to interfacing future photonic integrated circuits with electronics. However, fabricating the gap sizes (< λg/10) required of plasmonic resonating nanogaps for efficient operation across telecommunication frequencies is highly challenging. Efficient coupling from waveguides to plasmonic nanogaps also remains a major source of loss. Here, we show that the key to merging these platforms lies in applying metamaterial/metasurface engineering principles to the design of the nanogap. Over the last decade, metamaterials and metasurfaces have emerged as a versatile toolkit for control and enhancement of light-matter interaction at application-driven wavelengths of interest in nanophotonic device platforms. We show that integrating a metagrating within a waveguide-coupled plasmonic nanogap made from Au, can enhance coupling to and from the silicon waveguides. Furthermore, the incorporation of the metasurface within the gap allows resonant response to be maintained at user-specified wavelength of interest with gaps as large as λg/5, drastically easing fabrication. Finally, we show that by incorporating a reconfigurable phase change chalcogenide alloy into the gap, non-volatile signal switching with modulation contrasts of up to 10:1 can be achieved across telecom frequencies.","PeriodicalId":13820,"journal":{"name":"International Conference on Nanoscience, Engineering and Technology (ICONSET 2011)","volume":"175 1","pages":"1219608 - 1219608-5"},"PeriodicalIF":0.0,"publicationDate":"2022-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82973452","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}
S. Roy, Snigdhadev Chakraborty, Lokesh Muruga, Rahul Vaippuly, Vandana Yadav, S. Bajpai, Privitha Edwina, Basudev Roy
The cell membrane has fluctuations due to thermal and athermal sources. That causes the membrane to flicker. Conventionally, only the normal (perpendicular to the membrane) fluctuations are studied and then used to ascertain the membrane properties like the bending rigidity. It is here that we introduce a different concept, namely the slope fluctuations of the cell membrane which can be modelled as a gradient of the normal fluctuations. This can be studied using a new technique where a birefringent particle placed on the membrane turns in the out of plane sense, called the pitch sense. We introduce the pitch detection technique in optical tweezers relying upon asymmetric scattering from a birefringent particle under crossed polarizers. We then go on to use this pitch detection technique to ascertain the power spectral density of membrane slope fluctuations and find it to be (frequency)−1 while the normal fluctuations yields (frequency)−5/3. We also explore a different regime where the cell is applied with the drug Latrunculin-B which inhibits actin polymerization and find the effect on membrane fluctuations. We find that even as the normal fluctuations now become (frequency)−4/3, the slope fluctuations spectrum still remains (frequency)−1, with exactly the same coefficient as the case when the drug was not applied. Thus, this presents a convenient opportunity to study the membrane parameters like bending rigidity as a function of time after applying the drug. This would be the first time the membrane bending rigidity could be studied as a function of time upon the application of Lat-B without reverting to AFM.
{"title":"Direct detection of cell membrane slope fluctuations upon adding Latrunculin B using optical tweezers and single probe particle","authors":"S. Roy, Snigdhadev Chakraborty, Lokesh Muruga, Rahul Vaippuly, Vandana Yadav, S. Bajpai, Privitha Edwina, Basudev Roy","doi":"10.1117/12.2626451","DOIUrl":"https://doi.org/10.1117/12.2626451","url":null,"abstract":"The cell membrane has fluctuations due to thermal and athermal sources. That causes the membrane to flicker. Conventionally, only the normal (perpendicular to the membrane) fluctuations are studied and then used to ascertain the membrane properties like the bending rigidity. It is here that we introduce a different concept, namely the slope fluctuations of the cell membrane which can be modelled as a gradient of the normal fluctuations. This can be studied using a new technique where a birefringent particle placed on the membrane turns in the out of plane sense, called the pitch sense. We introduce the pitch detection technique in optical tweezers relying upon asymmetric scattering from a birefringent particle under crossed polarizers. We then go on to use this pitch detection technique to ascertain the power spectral density of membrane slope fluctuations and find it to be (frequency)−1 while the normal fluctuations yields (frequency)−5/3. We also explore a different regime where the cell is applied with the drug Latrunculin-B which inhibits actin polymerization and find the effect on membrane fluctuations. We find that even as the normal fluctuations now become (frequency)−4/3, the slope fluctuations spectrum still remains (frequency)−1, with exactly the same coefficient as the case when the drug was not applied. Thus, this presents a convenient opportunity to study the membrane parameters like bending rigidity as a function of time after applying the drug. This would be the first time the membrane bending rigidity could be studied as a function of time upon the application of Lat-B without reverting to AFM.","PeriodicalId":13820,"journal":{"name":"International Conference on Nanoscience, Engineering and Technology (ICONSET 2011)","volume":"63 1","pages":"121980J - 121980J-9"},"PeriodicalIF":0.0,"publicationDate":"2022-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83477854","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}
Cosmin Constantin-Popescu, M. Shalaginov, F. Yang, Hung-I Lin, S. An, Christopher M. Roberts, P. Miller, M. Kang, K. Richardson, Hualiang Zhang, C. Rivero‐Baleine, Hyun Jung Kim, T. Gu, S. Vitale, Juejun Hu
Phase change materials or PCMs are truly remarkable compounds whose unique switchable properties have fueled an explosion of emerging applications in electronics and photonics. Nonetheless, if we discount their use in optical discs, PCMs’ immense application potential in photonics beyond data recording has only begun to unfold in the past decade. While the material requirements for optical or electronic data storage have been succinctly summarized as five key elements “writability, archival storage, erasability, readability, and cyclability” decades ago, these requirements are not universally relevant to the diverse set of photonic applications now being explored. It also comes as no surprise that existing PCMs, which have been heavily vetted for data storage, are not necessarily the optimal compositions for different use cases in optics and photonics. PCMs with their attributes custom-tailored for specific applications are therefore in demand as phase-change photonics continue to expand. Here we discuss the PCM selection and design strategies specifically for photonic applications as well as our recent work developing active integrated photonic devices and meta-surface optics based on new PCMs tailored for photonics.
{"title":"New phase change materials for active photonics","authors":"Cosmin Constantin-Popescu, M. Shalaginov, F. Yang, Hung-I Lin, S. An, Christopher M. Roberts, P. Miller, M. Kang, K. Richardson, Hualiang Zhang, C. Rivero‐Baleine, Hyun Jung Kim, T. Gu, S. Vitale, Juejun Hu","doi":"10.1117/12.2631038","DOIUrl":"https://doi.org/10.1117/12.2631038","url":null,"abstract":"Phase change materials or PCMs are truly remarkable compounds whose unique switchable properties have fueled an explosion of emerging applications in electronics and photonics. Nonetheless, if we discount their use in optical discs, PCMs’ immense application potential in photonics beyond data recording has only begun to unfold in the past decade. While the material requirements for optical or electronic data storage have been succinctly summarized as five key elements “writability, archival storage, erasability, readability, and cyclability” decades ago, these requirements are not universally relevant to the diverse set of photonic applications now being explored. It also comes as no surprise that existing PCMs, which have been heavily vetted for data storage, are not necessarily the optimal compositions for different use cases in optics and photonics. PCMs with their attributes custom-tailored for specific applications are therefore in demand as phase-change photonics continue to expand. Here we discuss the PCM selection and design strategies specifically for photonic applications as well as our recent work developing active integrated photonic devices and meta-surface optics based on new PCMs tailored for photonics.","PeriodicalId":13820,"journal":{"name":"International Conference on Nanoscience, Engineering and Technology (ICONSET 2011)","volume":"215 1","pages":"1219606 - 1219606-12"},"PeriodicalIF":0.0,"publicationDate":"2022-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83616343","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}
Jonas O. Brown, M. Taheri, Nick R. Sesing, T. Salguero, F. Kargar, A. Balandin
In this invited contribution, we review recent results and report on the phase transitions and de-pinning of the charge-density waves in single-crystal 1T-TaS2 thin-film and 1T-TaS2 / h-BN heterostructure devices. It is known that 1T-TaS2 reveals charge-density-wave phases below and above room temperature. The de-pinning of the charge-density waves in the quasi-2D materials is different from that in “conventional” bulk charge-density-wave materials with quasi-1D motifs in the crystal structure. The de-pinning process in 1T-TaS2 is not accompanied by an observable abrupt increase in electric current – in contrast to de-pinning in the conventional charge-density-wave materials with the quasi-1D crystal structure. The obtained results contribute to the development of the charge-density-wave devices for applications in electronics and optoelectronics.
{"title":"Charge-density-wave phase transitions in quasi-2D 1T-TaS2/h-BN heterostructure devices","authors":"Jonas O. Brown, M. Taheri, Nick R. Sesing, T. Salguero, F. Kargar, A. Balandin","doi":"10.1117/12.2637881","DOIUrl":"https://doi.org/10.1117/12.2637881","url":null,"abstract":"In this invited contribution, we review recent results and report on the phase transitions and de-pinning of the charge-density waves in single-crystal 1T-TaS2 thin-film and 1T-TaS2 / h-BN heterostructure devices. It is known that 1T-TaS2 reveals charge-density-wave phases below and above room temperature. The de-pinning of the charge-density waves in the quasi-2D materials is different from that in “conventional” bulk charge-density-wave materials with quasi-1D motifs in the crystal structure. The de-pinning process in 1T-TaS2 is not accompanied by an observable abrupt increase in electric current – in contrast to de-pinning in the conventional charge-density-wave materials with the quasi-1D crystal structure. The obtained results contribute to the development of the charge-density-wave devices for applications in electronics and optoelectronics.","PeriodicalId":13820,"journal":{"name":"International Conference on Nanoscience, Engineering and Technology (ICONSET 2011)","volume":"25 1","pages":"1220004 - 1220004-8"},"PeriodicalIF":0.0,"publicationDate":"2022-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72769111","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}
We model the effect of concentrated sunlight on CIGS thin-film graded-bandgap solar cells using an optoelectronic numerical model. For this purpose it is necessary first to solve the time-harmonic Maxwell equations to compute the electric field in the device due to sunlight and so obtain the electron-hole-pair generation rate. The generation rate is then used as input to a drift-diffusion model governing the flow of electrons and holes in the semiconductor components that predicts the current generated. The optical submodel is linear; however, the electrical submodel is nonlinear. Because the Shockley-Read-Hall contribution to the electron-hole recombination rate increases almost linearly at high electron/hole densities, the efficiency of the solar cell can improve with sunlight concentration. This is illustrated via a numerical study.
{"title":"Nonlinear effects in modeling thin-film graded-bandgap solar cells","authors":"Faiz Ahmad, B. Civiletti, A. Lakhtakia, P. Monk","doi":"10.1117/12.2632264","DOIUrl":"https://doi.org/10.1117/12.2632264","url":null,"abstract":"We model the effect of concentrated sunlight on CIGS thin-film graded-bandgap solar cells using an optoelectronic numerical model. For this purpose it is necessary first to solve the time-harmonic Maxwell equations to compute the electric field in the device due to sunlight and so obtain the electron-hole-pair generation rate. The generation rate is then used as input to a drift-diffusion model governing the flow of electrons and holes in the semiconductor components that predicts the current generated. The optical submodel is linear; however, the electrical submodel is nonlinear. Because the Shockley-Read-Hall contribution to the electron-hole recombination rate increases almost linearly at high electron/hole densities, the efficiency of the solar cell can improve with sunlight concentration. This is illustrated via a numerical study.","PeriodicalId":13820,"journal":{"name":"International Conference on Nanoscience, Engineering and Technology (ICONSET 2011)","volume":"12196 1","pages":"121960D - 121960D-4"},"PeriodicalIF":0.0,"publicationDate":"2022-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89352443","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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