This document summarizes Amirhossein Alikhanzadeh's Master's thesis which investigated the effects of beam scattering and beam wandering on laser beams passing through the off-gas duct of an Electric Arc Furnace. The study found that beam scattering due to dust particles and beam wandering caused by turbulence and temperature gradients made it difficult for laser beams to penetrate the duct. Experimental results showed that collecting lenses can help improve laser signal strength in the presence of beam wandering. The research aims to help develop in-situ laser measurement systems for better process control in the steel industry.
1) The document discusses using silver nanoparticles to enhance Raman scattering signals through surface enhanced Raman spectroscopy (SERS) for studying heat transport in quantum dots.
2) Different methods for synthesizing silver nanoparticles were explored and nanoparticles were used to significantly enhance, by at least a factor of 90, the Raman signal of a test molecule (crystal violet).
3) For future work, the researchers want to use the silver nanoparticles to enhance Raman scattering from quantum dots to study heat transport in these nanomaterials.
The document describes the design and development of a solar pumped Nd:YAG laser. It discusses using a Fresnel lens to focus sunlight onto a laser rod containing neodymium-doped yttrium aluminum garnet to optically pump the laser. The laser cavity and output coupler are also mentioned. Work done so far includes fabricating light guides, measuring focal length and spot size, and developing a cooling system. Simulations have been run to optimize positioning of the light guide and characterize loss mechanisms. The next steps are to place the laser rod in the cavity, align it, and attempt to achieve lasing output. Further optimization and characterization will follow if lasing is achieved.
This document discusses a study on the influence of artificial soiling on the power losses of different photovoltaic (PV) technologies. Four types of artificial soiling (salt, sand, fine dust, coarse dust) were deposited on glass samples at different inclinations. The direct and hemispherical transmittance of the soiled samples was measured. Power losses were then calculated for concentrating photovoltaics and crystalline silicon, cadmium telluride, and copper indium gallium selenide PV technologies. Measurements on crystalline silicon solar cells validated that the calculations accurately predicted the power losses. The study found that power losses were always higher for concentrating PV compared to other technologies for the same soiling conditions.
Coating Measurement Using Handheld X-Ray FluorescenceOlympus IMS
Coating Measurement Using Handheld X-Ray Fluorescence
Abstract
Handheld X-ray fluorescence (HHXRF) can be used to measure coating thicknesses with advantages in precision and portability compared to other technologies. For benchtop analysis, analyzing coatings applied over large surface areas often requires destructive procedures. HHXRF overcomes this limitation and provides a nondestructive coating thickness testing capability.
A simple, user-friendly calibration built into the instrument interface enables the use of a certified standard to determine up to three layers of accurate and precise coating thicknesses. HHXRF coating measurements, which are independent of the substrate material, provide a user the freedom to analyze any deposited coating comprised of elements Ti through Pu. Because of the large elemental range of analysis, many corrosion-, wear-, and adhesion-resistant coatings measured in labs near the site of action can benefit from the precise results returned by HHXRF.
Dr. Howard Schlossberg presents an overview of his program, Lasers and Optics, at the AFOSR 2013 Spring Review. At this review, Program Officers from AFOSR Technical Divisions will present briefings that highlight basic research programs beneficial to the Air Force.
High-accuracy laser spectrometers for wireless trace-gas sensor networksClinton Smith
The document outlines Clinton J. Smith's final public oral exam for his dissertation on developing laser spectrometers for wireless trace gas sensor networks. The dissertation aims to develop CO2 sensors for deployment in a real-time sensor network to monitor carbon fluxes over a broad area. The outline includes development of a wireless laser spectroscopic sensor node for atmospheric CO2 monitoring, quantifying and improving the accuracy of wireless sensor network nodes, developing a solar-powered distributed wireless CO2 monitoring network, techniques for real-time calibration, and conclusions. Laboratory and field tests show the sensors can accurately measure CO2 concentrations with precision below 1% and linear response over large concentration ranges.
Laser-Based Standoff Methane Sensors for Enhancing Coal Miner SafetyClinton Smith
This presentation shows a demonstration of the PSI & Heath Consultants Remote Methane Leak Detector (RMLD) being applied to remote detection of methane within coal mines to supplement existing technology to further enhance coal miner safety.
Ellipsometry- non destructive measuring methodViji Vijitha
Ellipsometry is a non-destructive optical technique that measures the change in polarization state of light upon reflection from or transmission through a sample. It can be used to characterize properties like thickness, composition, and crystallinity of thin films. The document discusses the history and principles of ellipsometry, experimental setups, data analysis techniques using modeling to extract sample properties, and applications in measuring films. Modeling involves using equations to describe light-material interactions and minimizing errors between calculated and measured polarization states.
1) The document discusses using silver nanoparticles to enhance Raman scattering signals through surface enhanced Raman spectroscopy (SERS) for studying heat transport in quantum dots.
2) Different methods for synthesizing silver nanoparticles were explored and nanoparticles were used to significantly enhance, by at least a factor of 90, the Raman signal of a test molecule (crystal violet).
3) For future work, the researchers want to use the silver nanoparticles to enhance Raman scattering from quantum dots to study heat transport in these nanomaterials.
The document describes the design and development of a solar pumped Nd:YAG laser. It discusses using a Fresnel lens to focus sunlight onto a laser rod containing neodymium-doped yttrium aluminum garnet to optically pump the laser. The laser cavity and output coupler are also mentioned. Work done so far includes fabricating light guides, measuring focal length and spot size, and developing a cooling system. Simulations have been run to optimize positioning of the light guide and characterize loss mechanisms. The next steps are to place the laser rod in the cavity, align it, and attempt to achieve lasing output. Further optimization and characterization will follow if lasing is achieved.
This document discusses a study on the influence of artificial soiling on the power losses of different photovoltaic (PV) technologies. Four types of artificial soiling (salt, sand, fine dust, coarse dust) were deposited on glass samples at different inclinations. The direct and hemispherical transmittance of the soiled samples was measured. Power losses were then calculated for concentrating photovoltaics and crystalline silicon, cadmium telluride, and copper indium gallium selenide PV technologies. Measurements on crystalline silicon solar cells validated that the calculations accurately predicted the power losses. The study found that power losses were always higher for concentrating PV compared to other technologies for the same soiling conditions.
Coating Measurement Using Handheld X-Ray FluorescenceOlympus IMS
Coating Measurement Using Handheld X-Ray Fluorescence
Abstract
Handheld X-ray fluorescence (HHXRF) can be used to measure coating thicknesses with advantages in precision and portability compared to other technologies. For benchtop analysis, analyzing coatings applied over large surface areas often requires destructive procedures. HHXRF overcomes this limitation and provides a nondestructive coating thickness testing capability.
A simple, user-friendly calibration built into the instrument interface enables the use of a certified standard to determine up to three layers of accurate and precise coating thicknesses. HHXRF coating measurements, which are independent of the substrate material, provide a user the freedom to analyze any deposited coating comprised of elements Ti through Pu. Because of the large elemental range of analysis, many corrosion-, wear-, and adhesion-resistant coatings measured in labs near the site of action can benefit from the precise results returned by HHXRF.
Dr. Howard Schlossberg presents an overview of his program, Lasers and Optics, at the AFOSR 2013 Spring Review. At this review, Program Officers from AFOSR Technical Divisions will present briefings that highlight basic research programs beneficial to the Air Force.
High-accuracy laser spectrometers for wireless trace-gas sensor networksClinton Smith
The document outlines Clinton J. Smith's final public oral exam for his dissertation on developing laser spectrometers for wireless trace gas sensor networks. The dissertation aims to develop CO2 sensors for deployment in a real-time sensor network to monitor carbon fluxes over a broad area. The outline includes development of a wireless laser spectroscopic sensor node for atmospheric CO2 monitoring, quantifying and improving the accuracy of wireless sensor network nodes, developing a solar-powered distributed wireless CO2 monitoring network, techniques for real-time calibration, and conclusions. Laboratory and field tests show the sensors can accurately measure CO2 concentrations with precision below 1% and linear response over large concentration ranges.
Laser-Based Standoff Methane Sensors for Enhancing Coal Miner SafetyClinton Smith
This presentation shows a demonstration of the PSI & Heath Consultants Remote Methane Leak Detector (RMLD) being applied to remote detection of methane within coal mines to supplement existing technology to further enhance coal miner safety.
Ellipsometry- non destructive measuring methodViji Vijitha
Ellipsometry is a non-destructive optical technique that measures the change in polarization state of light upon reflection from or transmission through a sample. It can be used to characterize properties like thickness, composition, and crystallinity of thin films. The document discusses the history and principles of ellipsometry, experimental setups, data analysis techniques using modeling to extract sample properties, and applications in measuring films. Modeling involves using equations to describe light-material interactions and minimizing errors between calculated and measured polarization states.
This document discusses uranium enrichment technology and processes. It explains that uranium exists as the isotopes U-238 and U-235, with U-235 being fissile. It then describes the main types and grades of enriched uranium and the primary processes used for enrichment, including gaseous diffusion, gas centrifuges, laser separation, and other techniques like aerodynamic, electromagnetic, chemical, and plasma separation methods.
This proposal seeks funding to develop laser-based optical trapping, or "tractor beams", for remote sampling of particles in space. Tractor beams could non-invasively collect samples from comets, asteroids, planetary atmospheres and surfaces. This would enable new types of sampling missions without landers or sample return. The proposal outlines developing tractor beam technology through lab experiments and scaling it for potential applications on spacecraft. Developing tractor beams could significantly expand NASA's capability to remotely collect and analyze samples throughout the solar system.
This document summarizes the experimental setup and results of comparing the output power of Nd:YAG and Nd:YVO4 lasers pumped by diode lasers. It describes the setup, which involves focusing an 808nm diode laser into each crystal separately. For each crystal, the threshold pump power and output power at increasing pump powers is measured. The results are plotted on a graph of input power versus output power. The document finds that Nd:YVO4 has a lower lasing threshold and higher slope efficiency compared to Nd:YAG. The aim is to study how pump power affects laser output power for each crystal.
Validate spectrophotometric measurements with certified UV/Vis reference mate...Hellma
Certified reference materials can be used to validate spectrophotometric measurements and ensure their traceability to international standards. Regular checks of UV/Vis spectrophotometers are required by organizations like ISO and USP to ensure measurement reliability. Parameters like photometric accuracy, wavelength accuracy, stray light level, and spectral resolution should be checked. Hellma Analytics' calibration laboratory is accredited to certify reference materials across the UV/Vis spectrum to support these validation needs.
This document provides an introduction to various spectroscopy techniques including absorption spectroscopy, emission spectroscopy, and mass spectrometry. It then discusses specific techniques like atomic absorption spectroscopy (AAS), flame emission spectroscopy (FES), and inductively coupled plasma atomic emission spectroscopy (ICP-AES). The key components, working principles, and applications of these techniques are described. Sample preparation procedures including drying, grinding, and acid digestion are also outlined. Finally, quality control procedures like replicates, spikes, and standard reference materials are mentioned.
Laser communication is well-suited for small spacecraft due to the small optics required. It uses modulation of a laser beam to transmit information, with technologies like laser diodes and sensitive detectors enabling communication over long distances using low power. Key components of a laser communication system include the laser source, modulation techniques, beam optics, photon sensors like CCDs or PMTs, and tracking systems to point the receiver at the transmitter.
Se-2000 for modular design provides modularity and high measurement performance in a compact table footprint. This cost effective tool includes automatic sample positioning suitable for R&D laboratories and production quality monitoring.
In this presentation, we cover how to pick the right technology to measure a coating thickness.
- An introduction to coatings
- Why coatings are used in industry
- Why to measure the thickness of a coating
- The best methods for coating thickness measurement
For more information, visit: Olympus-IMS.com.
This document describes an experiment using Talbot interferometry to measure the pitch of a grating and focal lengths of lenses. Key aspects of the experiment include using a He-Ne laser and Ronchi grating to generate interference patterns, which are analyzed using a CCD camera and microscope to determine pitch and focal lengths. Results found grating pitch within 1% error and lens focal lengths within 2% error. Talbot interferometry provides a simple optical system for these measurements but is limited by bench length and angle measurement devices. The phenomenon has applications in other fields like cold atoms and medical imaging.
fr2.t03.5.2-micron IPDA Presentation at IGARSS-2011-Final-Revised-1.pptxgrssieee
This document describes the development of a high repetition rate, solid-state 2-micron pulsed laser for measuring carbon dioxide from airborne and space-based platforms. Key achievements include developing a double-pulsed, high energy 2-micron laser transmitter meeting requirements for profiling and column CO2 measurements. Ground tests demonstrated precision within 0.7% for column measurements. The laser design and performance meet requirements for direct detection pulsed integrated path differential absorption lidar for potential space-based carbon dioxide monitoring missions.
This document summarizes the major components of instrumentation used in absorption and emission spectroscopy experiments. It discusses common light sources, wavelength selectors like monochromators and filters, sample containers, detectors such as phototubes and photodiode arrays, and examples of single beam and double beam spectrophotometers. Key components are the light source, wavelength selector to produce monochromatic radiation, sample holder, and detector to measure the detectable output over the wavelength region of interest.
2019-06-07 Characterization and research of semiconductors with an FTIR spect...LeonidBovkun
2019-06-07 Educational seminar at EP-3 University of Wuerzburg
I will present particular experiments and related results with FTIR spectrometer, so one may consider these experiments complimentary for you research.
Raman Analysis of Carbon Nanostructures draft3Nadav Kravitz
This document summarizes a student's work analyzing carbon nanostructures using Raman spectroscopy. The student developed MATLAB tools to process Raman spectral data and fit peaks. They aimed to collect Raman images of single-walled carbon nanotubes on silicon wafers. Additionally, the student sought to develop atomic force microscopy and tip-enhanced Raman spectroscopy techniques to simultaneously obtain Raman and surface topology data with nanoscale resolution. Future work would involve continuing to improve analysis tools and applying various microscopy methods to research on carbon nanotechnology and standardization.
The document summarizes the development and characterization of a tunable AlGaN-based solar-blind UV-sensitive Schottky photodiode. It discusses the background of UV-sensitive sensor materials and devices, properties of UV radiation and its applications. It also covers the fundamentals of wide-bandgap semiconductors, AlGaN semiconductors, Schottky diodes and photocurrent generation. The experimental section details the electrical and spectral characterization methodology, as well as the optoelectronic characterization system used.
Explore how SWIR cameras, particularly NIT HiPe SenS, bring benefits for low light and long exposure time applications (Microscopy, Biomedical, Semiconductor Inspection, etc. )
For more information about NIT, please visit: https://new-imaging-technologies.com/ or contact us at info@new-imaging-technologies.com
Designing a low cost UV-Exposure System for Optical MicrolithographySushenDhali
Designing a low cost (about 52 $) UV-Exposure system for lithography and other UV-ray induced chemical reactions. These slides also describes detail process of photolithography.
This document discusses optical lithography and the challenges of achieving high resolution for integrated circuit fabrication. It covers the lithography process, the role of lithography in IC fabrication, and resolution challenges like diffraction. It then describes several lithography methods used today or under development to improve resolution, including proximity lithography, contact lithography, projection lithography, phase-shifting masks, immersion lithography, and extreme ultraviolet lithography (EUVL). The document focuses on EUVL and the associated challenges of mask design and multilayer optics required for EUV wavelengths. It concludes with a section on simulating an EUV lithography system.
New Directions in Structural Biology at Diamondwarwick_amr
This document discusses new developments in structural biology at Diamond Light Source. It begins by providing background on Diamond Light Source, describing it as the UK's third generation synchrotron facility. It then discusses several new techniques for structural determination, including serial femtosecond crystallography using X-ray free electron lasers. Diamond is establishing a user hub to facilitate UK access to XFELs. Fixed target approaches using microfluidic chips and acoustic drop ejection allow high hit rates with low sample consumption for serial crystallography experiments at XFELs and Diamond. These techniques are enabling structure determination from smaller and more sensitive crystals.
Industrial radiography uses X-rays and gamma rays to evaluate materials and objects without damaging them. It has applications in many fields including manufacturing, transportation, infrastructure inspection, security screening, and food processing. Some examples given are using radiography to detect defects in ceramic castings and battery electrodes, inspect bridges and aircraft parts, screen luggage and cargo for explosives, and treat food to kill bacteria and delay spoilage. Radiography is also used in other non-destructive applications such as geology, art conservation, and archaeology.
FSO networks under turbulence - Northumbria University 2013 Research ConferenceJoaquin Perez
FSO networks: understanding route diversity under turbulence phenomena towards reliable FSO mesh networks design.
In last mile extensions of MANs, wireless mesh networks are multi-hop networks being used as backbone networks connecting end-users with the access points connected to the Internet. Wireless mesh networks are an attractive option over optical fibres because of their ease of installation and cost effectiveness of deployment[1]. Moreover, Free Space Optics (FSO) technology is an attractive option for use in mesh networks [2, 3]. However, time-variant influence of the atmosphere in FSO links that introduces one of the main drawbacks [4]. In order to overcome the turbulence induced fading in FSO systems, several techniques have been proposed These include: spatial transmitter/receiver diversity [5] [6]; adaptive beam forming [7]; wavelength diversity [8], multiple-beam communication [9], novel modulation techniques and hybrid RF/optical link scheme. Moreover, topology design and routing are essential tools for FSO mesh networks performance. The turbulence phenomena also influences in the topology and routing design of complex FSO networks, then route diversity techniques will improve the mesh network reliability [14]. For example, route diversity application within mesh optical networks deployed Tokyo provided interesting experiment results in [15]. This presentation will offer an overview of turbulence phenomena on FSO mesh networks from route diversity point of view.
References
[1] I. F. Akyildiz, X. Wang, and W. Wang, "Wireless mesh networks: a survey," Computer Networks, vol. 47, pp. 445-487, 2005.
[2] Z. Hu, P. Verma, and J. J. Sluss, "Improved reliability of free-space optical mesh networks through topology design," J. Opt. Netw., vol. 7, pp. 436-448, 2008.
[3] A. Kashyap, K. Lee, M. Kalantari, S. Khuller, and M. Shayman, "Integrated topology control and routing in wireless optical mesh networks," Computer Networks, vol. 51, pp. 4237-4251, 2007.
[4] Z. Ghassemlooy, W. Popoola, and S. Rajbhandari, Optical Wireless Communications : System and Channel Modelling with MATLAB: CRC Press 2012.
[5] S. M. Navidpour, M. Uysal, and M. Kavehrad, "BER performance of free-space optical transmission with spatial diversity," IEEE Trans. Wireless Commun., vol. 6, pp. 2813-2819, Aug 2007.
[6] H. Moradi, H. H. Refai, and P. G. LoPresti, "Switch-and-stay and switch-and-examine dual diversity for high-speed free-space optics links," IET Optoelectron, vol. 6, pp. 34-42, 2012.
[7] R. K. Tyson, "Bit-error rate for free-space adaptive optics laser communications," J. Opt. Soc. Am. A:, vol. 19, pp. 753-758, Apr 2002.
[8] V. Weerackody and A. R. Hammons, "Wavelength Correlation in Free Space Optical Communication Systems," in Proceedings of IEEE Military Communications Conference 2006, 2006, pp. pp. 1-6.
This document summarizes several channel models used for free space optical (FSO) communication systems. It begins with an overview of the wireless channel model and introduces turbulence-induced fading models including the Kalmogorov, Hufnagel Valley Boundary, lognormal, gamma-gamma, negative exponential, K, and I-K models. For each model, the key equations that describe the irradiance distribution and calculate metrics like the scintillation index and bit error rate are presented. Simulation results are also shown comparing the BER performance for different models under varying channel conditions. The document provides a comprehensive overview of the most common channel models used to characterize FSO links.
Free space optical communication (FSO) uses lasers and photo detectors to transmit data through the air without fiber cables. It was initially developed by NASA and the military. FSO can transmit data, voice, or video at speeds up to 1.25 Gbps using invisible beams of light in a line-of-sight system. Signal propagation is impacted by weather like fog and rain, which can cause scattering and absorption leading to power losses and interruptions. While installation has low costs compared to fiber, FSO performance depends on clear line-of-sight conditions.
This document discusses uranium enrichment technology and processes. It explains that uranium exists as the isotopes U-238 and U-235, with U-235 being fissile. It then describes the main types and grades of enriched uranium and the primary processes used for enrichment, including gaseous diffusion, gas centrifuges, laser separation, and other techniques like aerodynamic, electromagnetic, chemical, and plasma separation methods.
This proposal seeks funding to develop laser-based optical trapping, or "tractor beams", for remote sampling of particles in space. Tractor beams could non-invasively collect samples from comets, asteroids, planetary atmospheres and surfaces. This would enable new types of sampling missions without landers or sample return. The proposal outlines developing tractor beam technology through lab experiments and scaling it for potential applications on spacecraft. Developing tractor beams could significantly expand NASA's capability to remotely collect and analyze samples throughout the solar system.
This document summarizes the experimental setup and results of comparing the output power of Nd:YAG and Nd:YVO4 lasers pumped by diode lasers. It describes the setup, which involves focusing an 808nm diode laser into each crystal separately. For each crystal, the threshold pump power and output power at increasing pump powers is measured. The results are plotted on a graph of input power versus output power. The document finds that Nd:YVO4 has a lower lasing threshold and higher slope efficiency compared to Nd:YAG. The aim is to study how pump power affects laser output power for each crystal.
Validate spectrophotometric measurements with certified UV/Vis reference mate...Hellma
Certified reference materials can be used to validate spectrophotometric measurements and ensure their traceability to international standards. Regular checks of UV/Vis spectrophotometers are required by organizations like ISO and USP to ensure measurement reliability. Parameters like photometric accuracy, wavelength accuracy, stray light level, and spectral resolution should be checked. Hellma Analytics' calibration laboratory is accredited to certify reference materials across the UV/Vis spectrum to support these validation needs.
This document provides an introduction to various spectroscopy techniques including absorption spectroscopy, emission spectroscopy, and mass spectrometry. It then discusses specific techniques like atomic absorption spectroscopy (AAS), flame emission spectroscopy (FES), and inductively coupled plasma atomic emission spectroscopy (ICP-AES). The key components, working principles, and applications of these techniques are described. Sample preparation procedures including drying, grinding, and acid digestion are also outlined. Finally, quality control procedures like replicates, spikes, and standard reference materials are mentioned.
Laser communication is well-suited for small spacecraft due to the small optics required. It uses modulation of a laser beam to transmit information, with technologies like laser diodes and sensitive detectors enabling communication over long distances using low power. Key components of a laser communication system include the laser source, modulation techniques, beam optics, photon sensors like CCDs or PMTs, and tracking systems to point the receiver at the transmitter.
Se-2000 for modular design provides modularity and high measurement performance in a compact table footprint. This cost effective tool includes automatic sample positioning suitable for R&D laboratories and production quality monitoring.
In this presentation, we cover how to pick the right technology to measure a coating thickness.
- An introduction to coatings
- Why coatings are used in industry
- Why to measure the thickness of a coating
- The best methods for coating thickness measurement
For more information, visit: Olympus-IMS.com.
This document describes an experiment using Talbot interferometry to measure the pitch of a grating and focal lengths of lenses. Key aspects of the experiment include using a He-Ne laser and Ronchi grating to generate interference patterns, which are analyzed using a CCD camera and microscope to determine pitch and focal lengths. Results found grating pitch within 1% error and lens focal lengths within 2% error. Talbot interferometry provides a simple optical system for these measurements but is limited by bench length and angle measurement devices. The phenomenon has applications in other fields like cold atoms and medical imaging.
fr2.t03.5.2-micron IPDA Presentation at IGARSS-2011-Final-Revised-1.pptxgrssieee
This document describes the development of a high repetition rate, solid-state 2-micron pulsed laser for measuring carbon dioxide from airborne and space-based platforms. Key achievements include developing a double-pulsed, high energy 2-micron laser transmitter meeting requirements for profiling and column CO2 measurements. Ground tests demonstrated precision within 0.7% for column measurements. The laser design and performance meet requirements for direct detection pulsed integrated path differential absorption lidar for potential space-based carbon dioxide monitoring missions.
This document summarizes the major components of instrumentation used in absorption and emission spectroscopy experiments. It discusses common light sources, wavelength selectors like monochromators and filters, sample containers, detectors such as phototubes and photodiode arrays, and examples of single beam and double beam spectrophotometers. Key components are the light source, wavelength selector to produce monochromatic radiation, sample holder, and detector to measure the detectable output over the wavelength region of interest.
2019-06-07 Characterization and research of semiconductors with an FTIR spect...LeonidBovkun
2019-06-07 Educational seminar at EP-3 University of Wuerzburg
I will present particular experiments and related results with FTIR spectrometer, so one may consider these experiments complimentary for you research.
Raman Analysis of Carbon Nanostructures draft3Nadav Kravitz
This document summarizes a student's work analyzing carbon nanostructures using Raman spectroscopy. The student developed MATLAB tools to process Raman spectral data and fit peaks. They aimed to collect Raman images of single-walled carbon nanotubes on silicon wafers. Additionally, the student sought to develop atomic force microscopy and tip-enhanced Raman spectroscopy techniques to simultaneously obtain Raman and surface topology data with nanoscale resolution. Future work would involve continuing to improve analysis tools and applying various microscopy methods to research on carbon nanotechnology and standardization.
The document summarizes the development and characterization of a tunable AlGaN-based solar-blind UV-sensitive Schottky photodiode. It discusses the background of UV-sensitive sensor materials and devices, properties of UV radiation and its applications. It also covers the fundamentals of wide-bandgap semiconductors, AlGaN semiconductors, Schottky diodes and photocurrent generation. The experimental section details the electrical and spectral characterization methodology, as well as the optoelectronic characterization system used.
Explore how SWIR cameras, particularly NIT HiPe SenS, bring benefits for low light and long exposure time applications (Microscopy, Biomedical, Semiconductor Inspection, etc. )
For more information about NIT, please visit: https://new-imaging-technologies.com/ or contact us at info@new-imaging-technologies.com
Designing a low cost UV-Exposure System for Optical MicrolithographySushenDhali
Designing a low cost (about 52 $) UV-Exposure system for lithography and other UV-ray induced chemical reactions. These slides also describes detail process of photolithography.
This document discusses optical lithography and the challenges of achieving high resolution for integrated circuit fabrication. It covers the lithography process, the role of lithography in IC fabrication, and resolution challenges like diffraction. It then describes several lithography methods used today or under development to improve resolution, including proximity lithography, contact lithography, projection lithography, phase-shifting masks, immersion lithography, and extreme ultraviolet lithography (EUVL). The document focuses on EUVL and the associated challenges of mask design and multilayer optics required for EUV wavelengths. It concludes with a section on simulating an EUV lithography system.
New Directions in Structural Biology at Diamondwarwick_amr
This document discusses new developments in structural biology at Diamond Light Source. It begins by providing background on Diamond Light Source, describing it as the UK's third generation synchrotron facility. It then discusses several new techniques for structural determination, including serial femtosecond crystallography using X-ray free electron lasers. Diamond is establishing a user hub to facilitate UK access to XFELs. Fixed target approaches using microfluidic chips and acoustic drop ejection allow high hit rates with low sample consumption for serial crystallography experiments at XFELs and Diamond. These techniques are enabling structure determination from smaller and more sensitive crystals.
Industrial radiography uses X-rays and gamma rays to evaluate materials and objects without damaging them. It has applications in many fields including manufacturing, transportation, infrastructure inspection, security screening, and food processing. Some examples given are using radiography to detect defects in ceramic castings and battery electrodes, inspect bridges and aircraft parts, screen luggage and cargo for explosives, and treat food to kill bacteria and delay spoilage. Radiography is also used in other non-destructive applications such as geology, art conservation, and archaeology.
FSO networks under turbulence - Northumbria University 2013 Research ConferenceJoaquin Perez
FSO networks: understanding route diversity under turbulence phenomena towards reliable FSO mesh networks design.
In last mile extensions of MANs, wireless mesh networks are multi-hop networks being used as backbone networks connecting end-users with the access points connected to the Internet. Wireless mesh networks are an attractive option over optical fibres because of their ease of installation and cost effectiveness of deployment[1]. Moreover, Free Space Optics (FSO) technology is an attractive option for use in mesh networks [2, 3]. However, time-variant influence of the atmosphere in FSO links that introduces one of the main drawbacks [4]. In order to overcome the turbulence induced fading in FSO systems, several techniques have been proposed These include: spatial transmitter/receiver diversity [5] [6]; adaptive beam forming [7]; wavelength diversity [8], multiple-beam communication [9], novel modulation techniques and hybrid RF/optical link scheme. Moreover, topology design and routing are essential tools for FSO mesh networks performance. The turbulence phenomena also influences in the topology and routing design of complex FSO networks, then route diversity techniques will improve the mesh network reliability [14]. For example, route diversity application within mesh optical networks deployed Tokyo provided interesting experiment results in [15]. This presentation will offer an overview of turbulence phenomena on FSO mesh networks from route diversity point of view.
References
[1] I. F. Akyildiz, X. Wang, and W. Wang, "Wireless mesh networks: a survey," Computer Networks, vol. 47, pp. 445-487, 2005.
[2] Z. Hu, P. Verma, and J. J. Sluss, "Improved reliability of free-space optical mesh networks through topology design," J. Opt. Netw., vol. 7, pp. 436-448, 2008.
[3] A. Kashyap, K. Lee, M. Kalantari, S. Khuller, and M. Shayman, "Integrated topology control and routing in wireless optical mesh networks," Computer Networks, vol. 51, pp. 4237-4251, 2007.
[4] Z. Ghassemlooy, W. Popoola, and S. Rajbhandari, Optical Wireless Communications : System and Channel Modelling with MATLAB: CRC Press 2012.
[5] S. M. Navidpour, M. Uysal, and M. Kavehrad, "BER performance of free-space optical transmission with spatial diversity," IEEE Trans. Wireless Commun., vol. 6, pp. 2813-2819, Aug 2007.
[6] H. Moradi, H. H. Refai, and P. G. LoPresti, "Switch-and-stay and switch-and-examine dual diversity for high-speed free-space optics links," IET Optoelectron, vol. 6, pp. 34-42, 2012.
[7] R. K. Tyson, "Bit-error rate for free-space adaptive optics laser communications," J. Opt. Soc. Am. A:, vol. 19, pp. 753-758, Apr 2002.
[8] V. Weerackody and A. R. Hammons, "Wavelength Correlation in Free Space Optical Communication Systems," in Proceedings of IEEE Military Communications Conference 2006, 2006, pp. pp. 1-6.
This document summarizes several channel models used for free space optical (FSO) communication systems. It begins with an overview of the wireless channel model and introduces turbulence-induced fading models including the Kalmogorov, Hufnagel Valley Boundary, lognormal, gamma-gamma, negative exponential, K, and I-K models. For each model, the key equations that describe the irradiance distribution and calculate metrics like the scintillation index and bit error rate are presented. Simulation results are also shown comparing the BER performance for different models under varying channel conditions. The document provides a comprehensive overview of the most common channel models used to characterize FSO links.
Free space optical communication (FSO) uses lasers and photo detectors to transmit data through the air without fiber cables. It was initially developed by NASA and the military. FSO can transmit data, voice, or video at speeds up to 1.25 Gbps using invisible beams of light in a line-of-sight system. Signal propagation is impacted by weather like fog and rain, which can cause scattering and absorption leading to power losses and interruptions. While installation has low costs compared to fiber, FSO performance depends on clear line-of-sight conditions.
The document summarizes free space optical communication (FSO). It discusses the operation of FSO links, their advantages over fiber and microwave links, and applications. The key points are:
1. An FSO link consists of a transmitter, receiver, and tracking system to direct light beams between nodes. It allows license-free, high-speed connections but is susceptible to weather.
2. Applications include point-to-point links between buildings and potential mesh networks or use on high altitude platforms. Mesh networks provide better coverage but at a higher cost than point-to-point links.
3. Compared to fiber and microwave links, FSO systems have lower costs and power needs but higher data rates and
“Hybrid communication systems, FSO/RF and RoF: reliable and scaled communicat...Joaquin Perez
Title:
“Hybrid communication systems, FSO/RF and RoF: reliable and scaled communications anywhere”
Abstract:
Current network and telecommunication systems are required to provide higher data rates in access
networks to an increasing number of users. This fact is mainly due to the increase in the Internet
traffic data, which is related with the higher demand of online added-value online content, as a result
of a society increasingly more interconnected. New emergent radio technologies play a key role to
supply these high-demand services to customer, e.g., UWB, WIMAX and LTE-advanced. [1-3]
How to carry them to final customer? How to backup these services?
Free-space optics (FSO), Radio-over-fibre (RoF) and RF/FSO Hybrid communication systems
become a solution to deploy these services on indoor/outdoor scenarios avoiding architecture
problems on WAN environments, e.g., university campus, companies’ parks [4]. Moreover, these
systems will fit emergency scenarios, e.g. earthquakes, tsunamis, where the classical
communications infrastructure cost and time replacement is very high [5]. On the other hand, the
implementation of RF/FSO or RoF systems are enclosed in the new green communications issues,
because they share the common goal to implement energy efficiency communications at anywhere
scenario [6, 7]. Therefore, emergent radio technologies and their application on FSO and RoF
systems are a challenging research issue nowadays.
(abstract = 190 words)
References:
[1] J. Perez, M. Morant, M. Beltran, and R. Llorente, "Performance of MB-OFDM UWB and
WiMAX IEEE 802.16e Converged Radio-over-Fiber in PON," Mwp: 2009 International Topical
Meeting on Microwave Photonics, pp. 235-238, 2009.
[2] J. Perez, M. Morant, R. Llorente, and J. Marti, "Joint Distribution of Polarization-Multiplexed
UWB and WiMAX Radio in PON," Journal of Lightwave Technology, vol. 27, pp. 1912-1919,
Jun 15 2009.
[3] R. Llorente, T. Alves, M. Morant, M. Beltran, J. Perez, A. Cartaxo, and J. Marti, "Ultrawideband
radio signals distribution in FTTH networks," IEEE Photonics Technology Letters,
vol. 20, pp. 945-947, May-Jun 2008.
[4] E. Leitgeb, M. S. Awan, P. Brandl, T. Plank, C. Capsoni, R. Nebuloni, T. Javornik, G. Kandus,
S. S. Muhammad, F. Ghassemlooy, M. Loschnigg, and F. Nadeem, "Current Optical
Technologies for Wireless Access," Contel 2009: Proceedings of the 10th International
Conference on Telecommunications, pp. 7-17, 2009.
[5] S. Bloom, E. Korevaar, J. Schuster, and H. Willebrand, "Understanding the performance of
free-space optics [Invited]," J. Opt. Netw., vol. 2, pp. 178-200, 2003.
[6] Z. Yi, P. Chowdhury, M. Tornatore, and B. Mukherjee, "Energy Efficiency in Telecom Optical
Networks," Communications Surveys & Tutorials, IEEE, vol. 12, pp. 441-458.
[7] R. S. Tucker, "Green Optical Communications---Part II: Energy Limitations in Networks,"
Selected Topics in Quantum Electronics, IEEE Journal of, vol. PP, pp. 1-14.
This document provides an overview of indoor radio planning procedures for mobile network operators. It discusses:
1. The importance of indoor coverage for operators from both technical and commercial perspectives such as improving service quality and maximizing revenue.
2. The key steps in indoor radio planning including site surveys, coverage planning, capacity planning, antenna placement, link budget calculations, and traffic dimensioning using Erlang calculations.
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FSM roughness metrology for diffusers and very rough surfaces phot west 17 bWojtek Walecki
This document describes a system for polarization-resolved grazing angle scatterometry to monitor roughness for diffusers used in light-emitting device manufacturing. The system offers several advantages including immunity to vibration and stray light, eye-safe operation, integration with OEM solutions, and vacuum compatibility. Simulation results show polarization effects are important for characterizing very rough samples in backscatter geometry. Experimental data demonstrates excellent agreement between measurements of GaN diffusers and atomic force microscopy. The system provides rapid acquisition times of 0.1-0.7 seconds with high accuracy, linearity, and repeatability for roughness characterization from 200nm to 5um.
It is an analytical technique uselful for detection of functional groups present in particular molecules and compounds.
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Analysis Of Carbon Nanotubes And Quantum Dots In A Photovoltaic Device Slide ...M. Faisal Halim
Francis' presentation to Louis Stokes Association for Minority Participation. Since I co-authored this work I think I have the right to a copy. I was the graduate student Francis was working with.
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Synchrotron radiation is produced when electrons are accelerated radially in a storage ring. Electrons are injected into the storage ring using a linear accelerator and booster ring to achieve energies of 2-8 GeV. Magnets such as dipoles, quadrupoles and sextupoles are used to focus and steer the electron beam. Insertion devices like wigglers and undulators produce intense beams of synchrotron radiation. Beamlines transport this radiation from the storage ring to experimental end stations, where samples are analyzed using techniques like diffraction and spectroscopy.
It state about a transducer by using ; we can harness the energy of sun for our own electrical purposes. Simply using a Renewable Resource for our consumption.
FSM 8108 VITE presented at Spie Optics Photonics 2017Wojtek Walecki
Frontier Semiconductor is introducing a new metrology tool, the FSM 8108 VITE, which uses a novel Fabry Perot fringe stretching system to improve on their existing FSM 413 tool. The FSM 8108 VITE allows for faster, more accurate thickness measurements of semiconductor structures from 5 um to 3 mm thick on both stationary and moving wafers. It functions by adding an element of known optical thickness to reflected light from the sample, producing interference patterns that reveal the difference between the sample's thickness and the known thickness element. This enables thickness measurements with a small spectrometer without needing high resolution. The tool is expected to improve throughput for applications like measuring patterned layers, bonded wafers, bumped wafers
Introduction to nanoscience and nanotechnologyaimanmukhtar1
Introduction of nanoscience/nanotechnology ,properties/potential applications of nanomaterials and electrodeposition of metal single component and alloy nanowires in AAO template
Effect of Laser Induced Tin Oxide (SnO2) Nano particleIRJET Journal
The document summarizes a study on the effect of laser irradiation on tin oxide (SnO2) nanoparticles. Key findings include:
1) X-ray diffraction analysis showed the laser treated SnO2 has a tetragonal rutile crystalline structure with particle sizes ranging from 4-6nm.
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This document presents the design and development of a solar pumped Nd:YAG laser system. It discusses the motivation for using sunlight as the pumping source instead of traditional power supplies. The basic design of the system includes a Fresnel lens for solar concentration, a light guide to transport the sunlight, a laser cavity with Nd:YAG laser rod, and an output coupler. Characterization of the laser rod and other components is also presented. Experimental results show emission spectra when pumping with both solar energy and an 808 nm diode laser. Future applications of this prototype solar laser system include material processing, sensing, and deep space communications.
Spectrophotometry methods for molecule analysisygpark2221
The document discusses instrumental analysis using spectrophotometric techniques. It begins by outlining the main components of a spectrophotometer including light sources, monochromators, and detectors. It then provides background on the properties of light and its interaction with matter including absorption, excitation and emission. The document discusses the principles of different types of optical spectroscopy techniques and the components and design of spectrophotometers including single beam vs double beam instruments and the purpose of monochromators and slits. It also covers luminescence spectroscopy concepts like fluorescence and phosphorescence.
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This document provides an overview of infrared spectroscopy. It discusses:
1) The principle of infrared spectroscopy is that infrared radiation is absorbed by molecules at frequencies that match the natural vibrational frequencies of bonds within the molecules.
2) Infrared instrumentation includes sources that emit infrared radiation like incandescent lamps, detectors that sense absorbed radiation like bolometers and thermocouples, and components that separate wavelengths like prisms.
3) Samples can be analyzed as solids, liquids between salt plates, or gases in gas cells to collect infrared absorption spectra that are characteristic of molecular structure.
This document provides information about generating monochromatic x-rays for x-ray diffraction analysis. It discusses how x-rays are produced through interactions between high-energy electrons and metal targets in an x-ray tube. This produces both continuous bremsstrahlung radiation and characteristic x-ray peaks. Various methods are described to filter the x-ray beam and produce a beam that is closer to monochromatic, including the use of beta filters made of materials like nickel that preferentially absorb lower energy x-rays. Common anode materials like copper, chromium, and iron are discussed along with their characteristic x-ray wavelengths.
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Greg Smestad, Leonardo Micheli, Thomas Germer, and Eduardo Fernández presented research on characterizing the optical effects of soiling on PV glass and modules. They measured the transmission of glass coupons exposed outdoors at multiple locations over 8 weeks and found soiling reduced transmission more at shorter wavelengths. Particle area coverage on the coupons correlated linearly with reduced hemispherical transmittance. Angular measurements showed soiling impacts transmission more for direct light than hemispherical. The research aims to better understand how soiling impacts PV performance globally.
1. Amirhossein (Amir) Alikhanzadeh
Supervisor: Murray J. Thomson
Combustion Research Laboratory, Department of Mechanical
and Industrial Engineering
University of Toronto, Toronto, Ontario, Canada
Investigation of the effects of beam scattering and
beam wandering on laser beams passing thorough the
off-gas duct of an Electric Arc Furnace (EAF)
Master of Applied Science Thesis Defense
University of Toronto, Ontario
December 10th , 2014
2. Project Overview
2
TDL unable to
penetrate EAF
off –gas duct
Beam scattering
due to collision
with dust particles
Literature review -
Model
Rayleigh
scattering
Mie scattering
Geometric
scattering
Experiment In lab
Beam wandering
due to turbulence
and temperature
gradient
Experiment
In lab
Vertical Flow reactor
(VFR)
3. 3
Motivation : Steel industry
- Uses primarily scrap steel
- Lower energy consumption
- Regulations on the emissions
- 12 to 14 Billion $ sale in Canada (2012)
- High production
- Recycling rate of 40 % to 60 % in
Canada (7 million tonnes recycled in
2012)
- 7.5 % of industrial energy use
BENCHMARKING ENERGY INTENSITY IN THE CANADIAN STEEL INDUSTRY
(Prepared by Natural resources Canada)
EAF 2002 Energy intensity indicator
(MJ/tonnes of Hot Rolled Product)
4. 4
Electric Arc Furnace – Process control
- Heats charged material by means of electric arc
- Consists of three holes plus a “fourth hole” off-gas extraction
- Off-gas temperature of around 1400 degrees Celsius
Courtesy of Yuhui Sun [University of Toronto]
5. 5
Objective: How important is this
study? Zolo - SCAN
- Zolo-SCAN
- System developed for in-situ measurement
- Difficulty getting the beam over the path
length of the exhaust duct
- Critical Path Length; two reasons
6. 6
Objective: How important is this
study? LINDARC
- Based on TDLAS
- Water cooled rod
- Making readings at the centre
- Reasons similar to Zolo-SCAN
7. 7
Problems with the systems such as
LINDARC and Zolo-SCAN
Most of the issues come from having the rods:
- Dust accumulation
- Rod corrosion
- Damage to the equipment because of molten steel
- Bridging the gap (LINDARC) by means of molten steel
High maintenance expenditure
8. 8
Background: Light interaction with
medium
Light – medium
interaction
Attenuation
(Loss)
Absorption Scattering
Rayleigh
scattering
Mie scattering
Direction and
shape
Scintillation
Beam
wandering
9. 9
Background: What is beam
scattering?
Light interaction
with particles
Reflection (Light
deviated from its
original path
Refraction
Diffraction
Absorption
(Absorbed and
converted to heat)
Reflection
Refraction
Diffraction
Heat dissipation
10. 10
Scattering model: Mie theory
0
0.05
0.1
0.15
0.2
0.25
0.3
0.35
0.4
0 0.5 1 1.5 2 2.5 3 3.5
Volumefraction
Particle diameter (microns)
Particle size distribution (Evans Group)
S-A sample Dust sample
-
Mie Scattering
• Particle size is comparable to the
wavelength
• Not heavily dependant on the
wavelength change
• Particle size parameter: 𝑥 =
𝜋𝑑
λ
12. Scattering model: Model implications – Changing
particle sizes and their distribution
Constant scattering area
- Total scattering area is kept the same while constituent particles are varied in size and
subsequently concentration
- The assumed particle sizes are 0.5,1,1.5,2,2.5 µm in diameter
Concentration of 1.5 micron = 0
Concentration of 1.5 micron = 25
Concentration of 1.5 micons = 50
Concentration of 1.5 micons = 75
Concentration of 1.5 micons = 100
0
5E+09
1E+10
1.5E+10
2E+10
2.5E+10
0.5 1
1.5
2
2.5
0.00E+00
2.50E+09
5.00E+09
7.50E+09
1.00E+10
Numberofparticles/cubicmeter
Particle size in microns 12
13. Scattering model: Model implications – Effects of
changing particle sizes and their distribution on light
transmission
13
- How NIR transmission is affected when the wavelength is close to the dominant particle sizes
0.5
0.6
0.7
0.8
0.9
1
0 25 50 75 100
I/I0
Percentage of 1.5 micron particles
Light transmission with change in particle size and concentration
VIS - Transmission
NIR- Transmission
MIR- Transmission
14. Scattering model: Model implications –
Effect of refractive index
0.8
0.9
1
1.2 1.3 1.4 1.5 1.6 1.7 1.8 1.9
LIGHTTRANSMISSION
REFRACTIVE INDEX
Light Transmission (VIS)
Light Transmission (NIR)
Light Transmission (MIR)
14
16. 16
Scattering Experiment: Result
- Model could not be
fully verified with
experiments
- The experiment
showed that model
implications of less
scattering at long
wavelength is held
- Although only
qualitative
measurements for
mass, it can be seen
that more particles
means more
attenuation of light
0
25
50
75
100
Talc - 4.4 g Talc - 7.8 g Al2O3 - 6.6 g Al2O3 - 5.6 g
Attenuation
Test ( Particles used - mass dropped in one minute)
Light attenuation from particle scattering
VIS - %Attenuation
NIR - %Attenuation
MIR - %Attenuation
17. 17
Scattering model: Real particle sizes
- Malvern Spraytec
- Agglomeration of the particles is
evident by comparison to Evans’
result
Talc
Aluminum oxide
Jamie Loh [University of Toronto]
18. 18
Scattering : Conclusions
Particle size
distribution
Particle weight %
distribution
Particle refractive
index
Incident
wavelength
Predict how much beam
is lost due to scattering
19. 19
Beam wandering due to
turbulence?
Turbulence
Time Steps
- Varying Temperature, Density and
Index of refraction through
turbulence
- Amplitude fluctuations Signal
fades
- Beam Wandering (Steering) –
Location movement
- or Scintillation Distorted beam
shape
https://www.youtube.com/watch?v=VEFEQUY-KNA&list=LLSmktf7Lsrml6zbh078Zing&index=2
20. 20
Turbulence: Theory
- Kolmogorov theory of turbulence
- Energy flow starts from the outer scale and cascades
to smaller scale
- Act as small lenses
- Light beam of diameter bigger than the eddy would
refract and smaller than the eddy broadens the
beam; the net effect is a combination of the two
Energy injection
Energy transfer
Energy dissipation
Lo
lo
21. 21
Beam wandering: Effects of
refractive index change
https://www.youtube.com/watch?v=bW6EcCcjFW0&index=4&list=PLKvrYlykYnYvXdpiffFtD2-jUrv7_2NJE
Laser Detector
Laser
Detector
LASER
LASER
DetectorDetector
a)
b)
Time
Lightbeampower
Lightbeampower
Time
Light beam Detector
(a)
Time
Lightbeampower
Lightbeampower
Time
Light beam Detector
(b)
Time
Lightbeampower
Lightbeampower
Time
Light beam
Detector
(a)
23. Beam wander: Small-scale
experiment implication
Amplitude = 0.0352* T
R² = 0.9825
0
5
10
15
20
0 100 200 300 400 500
Amplitude(cm)
Temp (oC)
DEVIATION FROM CENTRE OF THE DETECTOR VS HOT
PLATE SURFACE TEMPERATURE
23
- Linear relationship between temperature (gradient) and deviation from the detector
24. 24
Beam wandering: Experiment goal
- The experiment was designed to test if adding a large collecting lens
would improve the signal
Light beam Detector
Light beam Detector
(a)
(b)
Light beam Detector
Light beam Detector
(a)
(b)
25. 25
Beam wander: Experiment at the
Vertical Flow Reactor
Light beam
(VIS – NIR)
Detector movement
Front view
Collecting lens
Detector
(a)(b)
Plano convex lenses
Detector movement
Front view
2.5 cm
- 2.5 cm 2.5 cm
- 2.5 cm
(a) (b)
- Mapping the intensity of laser received
at the detector
Light beam
Detector movement
Front view
Collecting lens
(a)(b)
Detector movement
Front view
2.5 cm
- 2.5 cm 2.5 cm
- 2.5 cm
(a) (b)
Light beam
(VIS – NIR)
Detector movement
Front view
Collec
(a)(b)
Detector movement
Front view
2.5 cm
- 2.5 cm 2.5 cm
- 2.5 cm
(a) (b)
Light beam
(VIS – NIR)
Detector movement
Front view
Co
(a)(b)
Detector movement
Front view
2.5 cm
- 2.5 cm 2.5 cm
- 2.5 cm
(a) (b)
Light beam
(VIS – NIR)
Detector movement
Front view
Collec
(a)(b)
Detector movement
Front view
2.5 cm
- 2.5 cm 2.5 cm
- 2.5 cm
(a) (b)
Light beam
(VIS – NIR)
Detector movement
Front view
Collec
(a)(b)
Detector movement
Front view
2.5 cm
- 2.5 cm 2.5 cm
- 2.5 cm
(a) (b)
Light beam
(VIS – NIR)
Detector movement
Front view
Collec
(a)(b)
Detector movement
Front view
2.5 cm
- 2.5 cm 2.5 cm
- 2.5 cm
(a) (b)
Light beam
Detector movement
Front view
(a)(b)
Detector movement
Front view
2.5 cm
- 2.5 cm 2.5 cm
(a) (b)
Light beam
(VIS – NIR)
Detector movement
Front view
Co
(a)(b)
Detector movement
Front view
2.5 cm
- 2.5 cm 2.5 cm
- 2.5 cm
(a) (b)
Light beam
(VIS – NIR)
Detector movement
Front view
Co
(a)(b)
Detector movement
Front view
2.5 cm
- 2.5 cm 2.5 cm
- 2.5 cm
(a) (b)
Light beam
(VIS – NIR)
Detector movement
Front view
Co
(a)(b)
Detector movement
Front view
2.5 cm
- 2.5 cm 2.5 cm
- 2.5 cm
(a) (b)
Light beam
(VIS – NIR)
Detector movement
Front view
(b)
Detector movement
Front view
2.5 cm
2.5 cm 2.5 cm
- 2.5 cm
(a)
Light beam
Detector movement
Front view
(a)(b)
Detector movement
Front view
2.5 cm
- 2.5 cm 2.5 cm
- 2.5 cm
(a) (b)
Light beam
Detector movement
Front view
((b)
Detector movement
Front view
2.5 cm
- 2.5 cm 2.5 cm
- 2.5 cm
(a) (
Light beam
(VIS – NIR)
Detector movement
Front view
(b)
Detector movement
Front view
2.5 cm
- 2.5 cm 2.5 cm
- 2.5 cm
(a)
Light beam
Detector movement
Front view
(b)
Detector movement
Front view
2.5 cm
- 2.5 cm 2.5 cm
- 2.5 cm
(a)
Light beam
(VIS – NIR)
Detector movement
Front view
(b)
Detector movement
Front view
2.5 cm
- 2.5 cm 2.5 cm
- 2.5 cm
(a)
Light beam
Detector movement
Front view
(b)
Detector movement
Front view
2.5 cm
- 2.5 cm 2.5 cm
- 2.5 cm
(a)
Detector movement
Front view
(a)(b)
Detector movement
Front view
2.5 cm
- 2.5 cm 2.5 cm
(a) (b)Detector movement
Front view
(a)(b)
Detector movement
Front view
2.5 cm
- 2.5 cm 2.5 cm
(a) (b)
Detector movement
Front view
(a)(b)
Detector movement
Front view
2.5 cm
- 2.5 cm 2.5 cm
(a) (b)Detector movement
Front view
(a)(b)
Detector movement
Front view
2.5 cm
- 2.5 cm 2.5 cm
(a) (b)
Detector movement
Front view
(a)(b)
Detector movement
Front view
2.5 cm
- 2.5 cm 2.5 cm
(a) (b)Detector movement
Front view
(a)(b)
Detector movement
Front view
2.5 cm
- 2.5 cm 2.5 cm
(a) (b)
Detector movement
Front view
(a)(b)
Detector movement
Front view
2.5 cm
- 2.5 cm 2.5 cm
(a) (b)Detector movement
Front view
(a)(b)
Detector movement
Front view
2.5 cm
- 2.5 cm 2.5 cm
(a) (b)
Detector movement
Front view
Collecting
(a)(b)
Detector movement
Front view
2.5 cm
5 cm 2.5 cm
(a) (b)Detector movement
Front view
Collect
(a)(b)
Detector movement
Front view
2.5 cm
- 2.5 cm 2.5 cm
(a) (b)Detector movement
Front view
Collecting lens
(a)(b)
Detector movement
Front view
2.5 cm
m 2.5 cm
(a) (b)Detector movement
Front view
Collecting l
(a)(b)
Detector movement
Front view
2.5 cm
- 2.5 cm 2.5 cm
(a) (b)Detector movement
Front view
Collecting lens
(a)(b)
Detector movement
Front view
2.5 cm
2.5 cm
(a) (b)Detector movement
Front view
Collecting lens
(a)(b)
Detector movement
Front view
2.5 cm
2.5 cm 2.5 cm
(a) (b)Detector movement
Front view
Collecting lens
(a)(b)
Detector movement
Front view
2.5 cm
2.5 cm
) (b)Detector movement
Front view
Collecting lens
(a)(b)
Detector movement
Front view
2.5 cm
cm 2.5 cm
(a) (b)
26. 26
Beam wander: Near Infrared Laser
signal strength map on Vertical axes
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
-15 -10 -5 0 5 10 15
INTENSITY(V)
POSITION (MM)
NO HEAT - NO LENS HEATED - NO LENS
0
2
4
6
8
10
12
-6 -4 -2 0 2 4 6
INTENSITY(V)
POSITION (MM)
NO HEAT- WITH LENS HEATED - WITH LENS
Vertical axis – No lens Vertical axis – With lens
41 % drop
9 % drop
16 mm
6 mm
27. 27
Beam wander: Near Infrared Laser
signal strength map on Horizontal
0
2
4
6
8
10
12
-12 -7 -2 3 8
Intensity(V)
Horizontal Position (mm)
NO HEAT - NO
LENS
NO HEAT- WITH
LENS
HEATED - NO
LENS
HEATED - WITH
LENS
28. Beam wander: Visible Laser signal
strength map on Horizontal axis
0
0.15
0.3
0.45
0.6
0.75
0.9
1.05
1.2
1.35
-8 -7 -6 -5 -4 -3 -2 -1 0 1 2 3 4 5 6 7 8
Intensity(V)
Horizontal Position (mm)
NO HEAT - NO LENS
HEATED - NO LENS
HEATED - WITH LENS
28
29. Beam wander: Visible Laser signal
strength map on Vertical axis
0
0.15
0.3
0.45
0.6
0.75
0.9
1.05
1.2
1.35
-8 -7 -6 -5 -4 -3 -2 -1 0 1 2 3 4 5 6 7 8
Intensity(V)
Vertical Position (mm)
NO HEAT - NO LENS
HEATED - NO LENS
HEATED - WITH LENS
29
30. 30
Beam wander: Frequency of
occurrence - Method
- The “aperture” is fixed in position and the intensity of light inside the aperture is received
by the detector
http://www.pnas.org/content/111/34/12320.full
31. Beam wander: Frequency of
occurrence - Result
0000
25
75
0 0.00.00.00.0
34.2
60.7
4.7
0
25
50
75
100
1.4-1.51.3-1.41.2-1.31.1-1.21.0-1.10.9-10.8-0.9
PercentageofdatapointsinIntensitybin
Intensity (V)
VIS Source:Frequency of occurance
No Heat No Lens
Heated No Lens
Heated with Lens
31
- Adding the lens Higher power and peak, narrower profile
32. Beam wander: Frequency of
occurrence - Result
- Adding the lens Higher power and peak, narrower profile
0.000.000.000.000.000.000.000.000.000.000.00
37.25
59.80
2.94
0.00
0
20
40
60
80
100
NIR Source:Frequency of occurance
Mean centre data (NHNL)
Mean centre data (NHL)
Mean centre data (HNL)
Mean centre data (HL)
32
33. 33
Conclusion
Large collecting lens, continuous
monitoring of the temperature in
the medium for modeling
(Reduce fluctuation and improve signal strength)
Current wavelengths are mainly
Infra red; limitation in terms of
the dust particles that exist in the
off-gas duct
Zolo-SCAN, LINDARC: Define a
Critical Path Length, need robust
system, high maintenance
Moving to a longer wavelengths;
THz is a possible solution
(Minimize the effects of scattering)
Stronger signal
at the detector
35. 35
Future work: Model
Adding Rayleigh
and Geometric
scattering to
improve dynamic
range for particle
sizes
Find an
experimental
relationship
between the
concentration and
light transmission
36. 36
Future work: Experiment
Model the
conditions of
the turbulent
medium
Real –time
continuous
measurements of
the temperatures
inside the medium
Need improvement
in characterizing the
particle sizes and
distributions for the
scattering
predictions
37. 37
Acknowledgments
- Dr.Zhenyou Wang (University of Toronto)
- Dr. Arathi Padmanabhan (University of Toronto)
- Prof.Murray Thomson (University of Toronto)
39. 39
Background: Rayleigh scattering
- Responsible for blue sky
- Responsible for red sunset
- Preferential scattering
Rayleigh Scattering
• Particulate much smaller than wavelength
• RS ∝ 𝑑6
• RS ∝ λ−4
40. Scattering coefficient
- Responsible for blue sky
- Responsible for red sunset
- Preferential scattering
D-MIR D-NIR D-VIS
3.237212 1.480141 0.603516
0
2
4
6
1 1.2 1.4 1.6 1.8 2
SCATTERINGCOEFFICIENT
REFRACTIVE INDEX CHANGE FOR X=3
Scattering coefficient - x=2.5
Scattering coefficient - x=3
AVG
40
Editor's Notes
Reyleigh sigmas=f*e4*lambda0^4/6/pi/epsilon0^2/c^4*(1/lambda4)
Moolecular =Absorption
Aerosoles scattering (has orders of magnitude less in numbers) but Mie is applied and the effect is bigger (coefficient) compared to rayleigh
Attenuation coefficients depend on the dimension, chemical composition and the concentration of particles dispersed in the gasous medium.
Assumed spherical and homogenous
- Smoother if more orders of the Bessel function are used to generate the draph
BY looking at the plot of Mie attenuation factor it can be said that for larger particles the scattering becomes less dependant on the wavelength and approaches 2 which means that for large enough particles, the attenuation cross section is equal to twice its geometrical cross section.
BY looking at the plot of Mie attenuation factor it can be said that for larger particles the scattering becomes less dependant on the wavelength and approaches 2 which means that for large enough particles, the attenuation cross section is equal to twice its geometrical cross section.
BY looking at the plot of Mie attenuation factor it can be said that for larger particles the scattering becomes less dependant on the wavelength and approaches 2 which means that for large enough particles, the attenuation cross section is equal to twice its geometrical cross section.
Displays the importance of change in refractive index of the particles
Aluminum oxide was chosen with refractive index of 1.7682
Dust particles from Dofasco have 2.01
Beam spreading and wandering due to propagation through air pockets of varying Temperature, Density and Index of refraction
Results in random phase and amplitude variations Fading of the signal
Lens like air pockets result in randomized interference in the warfront of the beam
Is seen through beam Wandering (Steering) or Scintillation Distorted beam shape
Video: Experimental movie of laser beam changes due to atmospheric turbulence. The turbulence was "played" on a spatial light modulator and the resulting beam changes measured on a CCD. As the movie plays, so the strength of the turbulence is increasing. When the turbulence is very strong, one cannot see the original Gaussian beam any longer.
Reference : https://www.youtube.com/watch?v=VEFEQUY-KNA&index=2&list=LLSmktf7Lsrml6zbh078Zing
A well defined wave front will be distorted moving through a turbulent medium; scintillation, beam wander and broadening.
(n-1)=79e-6 p/T (p in mili bars and T in Kelvin) , small pressure variations and their quick dispersiondelta(n)=79e-6/(omega-1)*p/T^2*delta (T) and omega= cp/cv=1.4 for air.
Given the temperature structure parameter, refractive index structure can be found:
Cn=[79*10^-6p/T^2]CT and CT=Root(<(T1-T2)^2>)r^(-1/3).
Typical values STRONG-INTERMEDIATE-WEAK (5e-7 == 4e-8 ==8e-9)
If the beam diameter is larger than the all the turbuklence scale sizes, the turbules act like weak lenses that deflect the beam ina random way without changing its diameter. If not, diffraction and refraction happens and the beam profile is smeared out.
A constantly changing pattern at the end of the turbulent path is formed. If a small detector is placed at the beam, the result is scintillation which is fluctuations in the light intensity.
Video: https://www.youtube.com/watch?v=bW6EcCcjFW0&list=PLKvrYlykYnYvXdpiffFtD2-jUrv7_2NJE&index=4
From : Single-shot stand-off chemical identification of powders using random Raman lasing
He-Ne after propagating the full 400-m path length
From : Single-shot stand-off chemical identification of powders using random Raman lasing
He-Ne after propagating the full 400-m path length
The model has limitations in terms of the particle sizes that can be input to the model
Due to the same limitations in particles size parameter, the results of the model are only valid through far infrared region and cannot be used for longer wavelengths
By adding Rayleigh theory and geometric theory to the model, the dynamic range is vastly improved
The model assumes a linear relationship between the concentration of particles and the amount of light transmission; a more accurate relationship can be developed thorough experiments which improves the accuracy of the model; the assumption of linear relationship is valid for x~1 but for much higher concentrations may not be valid
Needs improvement on the particle size and concentration measurement; Scattering
Needs continuous measurements of temperature gradient of the medium to predict the laser beam behaviour; Beam Wandering
Reyleigh sigmas=f*e4*lambda0^4/6/pi/epsilon0^2/c^4*(1/lambda4)
Moolecular =Absorption
Aerosoles scattering (has orders of magnitude less in numbers) but Mie is applied and the effect is bigger (coefficient) compared to rayleigh
Reyleigh sigmas=f*e4*lambda0^4/6/pi/epsilon0^2/c^4*(1/lambda4)
Moolecular =Absorption
Aerosoles scattering (has orders of magnitude less in numbers) but Mie is applied and the effect is bigger (coefficient) compared to rayleigh