This document discusses polarized and polarimetric Raman spectroscopy techniques and their applications. It motivates combining Raman spectroscopy with full polarized light control to obtain advanced characterization methods. It describes experimental setups for polarized Raman spectroscopy and outlines applications like stress characterization in semiconductors. It also discusses polarimetric Raman spectroscopy, which measures Stokes vectors and Mueller matrices. This allows characterization of Raman bands, fluorescence, and Rayleigh scattering. Calibration of a polarimetric Raman setup is described along with an example application.
Raman spectroscopy is a spectroscopic technique that uses laser light to study vibrational, rotational, and other low-frequency modes in a system. It relies on inelastic scattering, or Raman scattering, of monochromatic light, usually from a laser in the visible, near infrared, or near ultraviolet range. The laser light interacts with molecular vibrations, phonons or other excitations in the system, resulting in the energy of the laser photons being shifted up or down. The shift in energy gives information about the vibrational modes in the system. Raman spectroscopy is commonly used in chemistry to provide a fingerprint by which molecules can be identified. It has applications in fields such as physics, materials science, biology, medicine and
Raman spectroscopy analyzes the scattering of electromagnetic radiation by molecules and materials. It can provide information about molecular vibrations, rotations, and bond characteristics. Raman spectra contain peaks corresponding to Stokes lines at lower frequencies and anti-Stokes lines at higher frequencies relative to the incident radiation. Rotational Raman spectroscopy of linear molecules follows selection rules of ΔJ = 0, ±2. Vibrational Raman spectroscopy requires a change in molecular polarizability during vibration.
Raman spectroscopy is a technique that uses lasers to study vibrational, rotational, and other low-frequency modes in a system. When light interacts with molecules, the light may be scattered at different wavelengths than the incident laser. This shift in wavelength provides information about molecular structure and symmetry. Raman spectroscopy can be used to examine inorganic, organic, and polymeric materials, determine molecular structure and interactions, and study chemical reactions and physical transformations.
This document reviews Raman spectroscopy, its applications, and compares it to infrared spectroscopy. It discusses how Raman spectroscopy works by inelastic scattering of monochromatic light, producing spectral lines near the laser frequency. Applications include identification of phases, measurement of stress, and identification of crystalline polymorphs. Both infrared and Raman spectroscopy produce spectra that can identify molecular structure based on vibrational frequencies, but they have different selection rules. Raman spectroscopy has advantages for samples that are aqueous or may contain fluorescence.
The document discusses the history and applications of Raman spectroscopy. It describes how Raman spectroscopy was discovered in 1928 by Sir C.V. Raman using sunlight and optical filters. Raman won the Nobel Prize in 1930 for this discovery. Raman spectroscopy provides information on a sample's chemical composition and molecular structure by analyzing the inelastic scattering of monochromatic light, usually from a laser. It is used to study vibrational, rotational, and other low-frequency modes in a system.
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.
Raman spectroscopy can analyze solids, liquids, gases, and mixtures with little to no sample preparation. It provides both qualitative identification and quantitative analysis of components in a mixture. Raman spectra can be acquired rapidly, even in just one second, and work through containers like glass and plastic. Raman can analyze aqueous samples and operate at various temperatures and pressures. The technique uses a narrowband 785nm laser that minimizes fluorescence and provides high sensitivity without being destructive to most samples.
Raman spectroscopy is a spectroscopic technique that uses laser light to study vibrational, rotational, and other low-frequency modes in a system. It relies on inelastic scattering, or Raman scattering, of monochromatic light, usually from a laser in the visible, near infrared, or near ultraviolet range. The laser light interacts with molecular vibrations, phonons or other excitations in the system, resulting in the energy of the laser photons being shifted up or down. The shift in energy gives information about the vibrational modes in the system. Raman spectroscopy is commonly used in chemistry to provide a fingerprint by which molecules can be identified. It has applications in fields such as physics, materials science, biology, medicine and
Raman spectroscopy analyzes the scattering of electromagnetic radiation by molecules and materials. It can provide information about molecular vibrations, rotations, and bond characteristics. Raman spectra contain peaks corresponding to Stokes lines at lower frequencies and anti-Stokes lines at higher frequencies relative to the incident radiation. Rotational Raman spectroscopy of linear molecules follows selection rules of ΔJ = 0, ±2. Vibrational Raman spectroscopy requires a change in molecular polarizability during vibration.
Raman spectroscopy is a technique that uses lasers to study vibrational, rotational, and other low-frequency modes in a system. When light interacts with molecules, the light may be scattered at different wavelengths than the incident laser. This shift in wavelength provides information about molecular structure and symmetry. Raman spectroscopy can be used to examine inorganic, organic, and polymeric materials, determine molecular structure and interactions, and study chemical reactions and physical transformations.
This document reviews Raman spectroscopy, its applications, and compares it to infrared spectroscopy. It discusses how Raman spectroscopy works by inelastic scattering of monochromatic light, producing spectral lines near the laser frequency. Applications include identification of phases, measurement of stress, and identification of crystalline polymorphs. Both infrared and Raman spectroscopy produce spectra that can identify molecular structure based on vibrational frequencies, but they have different selection rules. Raman spectroscopy has advantages for samples that are aqueous or may contain fluorescence.
The document discusses the history and applications of Raman spectroscopy. It describes how Raman spectroscopy was discovered in 1928 by Sir C.V. Raman using sunlight and optical filters. Raman won the Nobel Prize in 1930 for this discovery. Raman spectroscopy provides information on a sample's chemical composition and molecular structure by analyzing the inelastic scattering of monochromatic light, usually from a laser. It is used to study vibrational, rotational, and other low-frequency modes in a system.
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.
Raman spectroscopy can analyze solids, liquids, gases, and mixtures with little to no sample preparation. It provides both qualitative identification and quantitative analysis of components in a mixture. Raman spectra can be acquired rapidly, even in just one second, and work through containers like glass and plastic. Raman can analyze aqueous samples and operate at various temperatures and pressures. The technique uses a narrowband 785nm laser that minimizes fluorescence and provides high sensitivity without being destructive to most samples.
Raman spectroscopy involves scattering of monochromatic light, such as from a laser, when it interacts with molecular vibrations, phonons, or other excitations in the system being investigated. It relies on inelastic scattering, or Raman scattering, of monochromatic light, usually from a laser in the visible, near infrared, or near ultraviolet range. The laser light interacts with molecular vibrations, phonons or other excitations in the system, resulting in the energy of the laser photons being shifted up or down. The shift in energy gives information about the vibrational modes in the system. Raman spectroscopy is commonly used in chemistry to provide a fingerprint by which molecules can be identified. It can also be used to observe rotational
Raman spectroscpy presentation by zakia afzalzakia afzal
This document discusses Raman spectroscopy. It begins by explaining the Raman effect and how Raman scattering results in energy shifts from the excitation wavelength. It then describes the basic components of a Raman spectrometer and how Raman spectra are produced. Finally, it discusses several types of Raman spectroscopy techniques and how selection rules determine whether vibrational modes are Raman active or infrared active. In summary, the document provides an overview of Raman spectroscopy, including the underlying principles, instrumentation, and applications.
Raman spectroscopy and its applications are summarized. Key techniques discussed include resonance Raman spectroscopy, Raman microscopy, and surface-enhanced Raman spectroscopy. Applications covered include medical use for tissue analysis, forensics for explosive or ink detection, inspection of packaged products, analysis of artworks, and testing of silicon wafers. The document outlines the principles, instrumentation, and mechanisms of various Raman techniques.
This document provides an overview of Raman spectroscopy. It discusses the discovery of Raman spectroscopy and how it is used to observe vibration, rotational, and other low-frequency modes in a system. It also describes key aspects of Raman spectroscopy including the instrumentation, principle, types of molecules that show Raman spectra, quantum and classical theories, and applications to analyze rotational, vibrational, and pure rotational Raman spectra of molecules. In summary, the document serves as an introduction to Raman spectroscopy and its use in chemistry to identify molecules based on their unique Raman fingerprint.
This document provides information about the "Raman and Luminescence Submicron Spectroscopy" Laboratory located at the V. Lashkaryov Institute of Semiconductor Physics, National Academy of Science, Ukraine. The laboratory contains several lasers, spectrometers, microscopes, and temperature control equipment used to perform Raman and luminescence spectroscopy and mapping on semiconductor nanostructures with submicron spatial resolution. The laboratory studies properties such as chemical composition, strain, temperature, carrier mobility and concentration in nanostructures for applications in microelectronics and optoelectronics. Team members and their areas of research interest are also listed.
This content was presented by me in Sathayabama University, India as an Invited talk in a DBT sponsored training program which covers the generalized about the Raman Scattering technique.
Raman spectroscopy is a technique that uses lasers to study vibrational and rotational modes in molecules. It relies on inelastic scattering, where the molecule scatters light at wavelengths different from the laser beam due to changes in polarizability during vibrations. The document discusses the principle, instrumentation, advantages and applications of Raman spectroscopy. It can be used to study liquids, solids, and gases without the interference of water. Common applications include structure elucidation, biological analysis, and quantitative/qualitative analysis.
This document summarizes Raman spectroscopy. It discusses the theory behind Raman scattering and how it differs from Rayleigh scattering. It describes the major components of a Raman spectroscopy system including the laser source, sample compartment, spectrometer, detector, and computer. It also outlines some applications of Raman spectroscopy in chemistry and solid-state physics such as molecular fingerprinting and materials characterization.
This document provides an overview of Raman spectroscopy. It discusses Raman scattering, which is the inelastic scattering of monochromatic light, usually from a laser, by molecules or atoms excited to higher vibrational or rotational energy levels. There are two types of Raman scattering: Stokes Raman scattering where the material absorbs energy and anti-Stokes Raman scattering where the material loses energy. Raman spectroscopy can be used to identify molecules and provide information about chemical bonds and molecular symmetry. It has various applications including medical use, detection of explosives, and investigation of historical documents.
Raman spectroscopy involves illuminating a sample with monochromatic light, usually from a laser in the visible, near infrared, or near ultraviolet range. Most of the scattered light is of the same wavelength as the incident light (Rayleigh scattering) but a small amount undergoes Raman scattering, resulting in light of different wavelengths. The shift in wavelength corresponds to changes in vibrational and rotational energy levels of molecules, providing a unique spectral fingerprint that can be used to identify molecular structures and compositions.
This document discusses Raman spectroscopy measurements of intensity and depolarization ratio. It explains that Raman spectroscopy measures molecular vibrations when light excites a sample's molecules. The Raman scattered light has parallel and perpendicular components relative to the incident light polarization. The depolarization ratio is the intensity ratio between the perpendicular and parallel components, indicating whether a vibration is symmetric. Factors like molecular symmetry and normal vibrational modes affect this ratio. A ratio below 0.75 indicates a totally symmetric vibration while 0.75 represents a non-symmetric vibration. The depolarization ratio helps interpret vibrations observed in Raman signals.
Raman spectroscopy analyzes the frequency shift of light scattered by matter due to molecular vibrations. Sir C.V. Raman discovered Raman scattering in 1928. Raman scattering occurs when photons interact with polarizable molecules, causing inelastic scattering where the photon's energy changes by the amount of a molecular vibration. This produces Stokes and anti-Stokes shifts from the incident light frequency. Resonance Raman spectroscopy enhances the Raman signal by matching the incident light frequency to an electronic transition.
This document provides an overview of Raman spectroscopy. It discusses how Raman spectroscopy works, including that it involves scattering of monochromatic light when it interacts with molecular vibrations, resulting in a shift in wavelength. It describes the discovery of the Raman effect by C.V. Raman and how Raman spectroscopy has advantages over infrared spectroscopy such as not being interfered with by water. The document also outlines the instrumentation used in Raman spectroscopy and applications such as analyzing inorganic and organic species.
Raman spectroscopy and infrared spectroscopy are both vibrational spectroscopy techniques but differ in their operating principles. Raman spectroscopy relies on inelastic scattering of monochromatic light, usually from a laser, while infrared spectroscopy relies on absorption of infrared light. Raman spectroscopy can be used to observe samples as solids, liquids, and gases without requiring preparation, and is suitable for aqueous solutions since water does not interfere with the signal. It has advantages over infrared spectroscopy for applications requiring minimal sample preparation and when analyzing biological samples in their native state.
Sir CV Raman was an Indian physicist who won the Nobel Prize in 1930 for his work on the Raman effect. He discovered that when light scatters from molecules, a small fraction of the light shifts to different wavelengths, which is now known as Raman scattering. Raman made many contributions in areas like X-ray diffraction, optics, and colloidal solutions. Raman spectroscopy uses the Raman effect to study materials by analyzing the scattering of monochromatic light. It provides a molecular fingerprint to identify compounds and detect molecular impurities. Both Raman and infrared spectroscopy are useful techniques to analyze materials, but Raman spectroscopy has advantages like avoiding interference from solvents and being able to detect IR-inactive modes.
Resonance Raman spectroscopy is a technique that enhances Raman scattering intensity when the laser excitation frequency matches an electronic transition of the compound being examined. This resonance effect can greatly increase the intensity of Raman bands, facilitating the study of compounds present at low concentrations. The intensity is directly proportional to the energy difference between the laser and electronic transition. The theory of resonance Raman is complex as the normal polarizability theory fails under resonance conditions. It allows selective study of specific parts of molecules and is useful for problems in biology and complexes materials.
Raman spectroscopy is a technique used for characterization and qualitative/quantitative analysis of research products. It provides a molecular fingerprint that can be used to identify samples. Raman spectroscopy is non-destructive and can be used to investigate artworks by identifying individual pigments and degradation products to learn about an artist's working methods. It also finds medical applications by allowing real-time monitoring of anesthetic and respiratory gas mixtures during surgery. The technique provides information on a sample's molecular structure, composition, and crystal orientation.
Introduction
The applications of microscopy in the forensic sciences are almost limitless. This is due in large measure to the ability of
microscopes to detect, resolve and image the smallest items of evidence, often without alteration or destruction. As a
result, microscopes have become nearly indispensable in all forensic disciplines involving the natural sciences. Thus, a
firearms examiner comparing a bullet, a trace evidence specialist identifying and comparing fibers, hairs, soils or dust, a
document examiner studying ink line crossings or paper fibers, and a serologist scrutinizing a bloodstain, all rely on
microscopes, in spite of the fact that each may use them in different ways and for different purposes.
The principal purpose of any microscope is to form an enlarged image of a small object. As the image is more greatly
magnified, the concern then becomes resolution; the ability to see increasingly fine details as the magnification is
increased. For most observers, the ability to see fine details of an item of evidence at a convenient magnification, is
sufficient. For many items, such as ink lines, bloodstains or bullets, no treatment is required and the evidence may
typically be studied directly under the appropriate microscope without any form of sample preparation. For other types of
evidence, particularly traces of particulate matter, sample preparation before the microscopical examination begins is
often essential. Types of Microscopes Used in the Forensic Sciences
A variety of microscopes are used in any modern forensic science laboratory. Most of these are light microscopes which
use photons to form images, but electron microscopes, particularly the scanning electron microscope (SEM), are finding
applications in larger, full service laboratories because of their wide range of magnification, high resolving power and
ability to perform elemental analyses when equipped with an energy or wavelength dispersive X-ray spectrometer.
Tapping into the Agri-Tourism Industry - Suggestions for Craft DistillersDianna Stampfler, CTA
Craft distillers are part of the overall agri-culinary-foodie-beverage tourism and tourism industry, where collaboration is key. #PureMichigan examples are provided.
Raman spectroscopy involves scattering of monochromatic light, such as from a laser, when it interacts with molecular vibrations, phonons, or other excitations in the system being investigated. It relies on inelastic scattering, or Raman scattering, of monochromatic light, usually from a laser in the visible, near infrared, or near ultraviolet range. The laser light interacts with molecular vibrations, phonons or other excitations in the system, resulting in the energy of the laser photons being shifted up or down. The shift in energy gives information about the vibrational modes in the system. Raman spectroscopy is commonly used in chemistry to provide a fingerprint by which molecules can be identified. It can also be used to observe rotational
Raman spectroscpy presentation by zakia afzalzakia afzal
This document discusses Raman spectroscopy. It begins by explaining the Raman effect and how Raman scattering results in energy shifts from the excitation wavelength. It then describes the basic components of a Raman spectrometer and how Raman spectra are produced. Finally, it discusses several types of Raman spectroscopy techniques and how selection rules determine whether vibrational modes are Raman active or infrared active. In summary, the document provides an overview of Raman spectroscopy, including the underlying principles, instrumentation, and applications.
Raman spectroscopy and its applications are summarized. Key techniques discussed include resonance Raman spectroscopy, Raman microscopy, and surface-enhanced Raman spectroscopy. Applications covered include medical use for tissue analysis, forensics for explosive or ink detection, inspection of packaged products, analysis of artworks, and testing of silicon wafers. The document outlines the principles, instrumentation, and mechanisms of various Raman techniques.
This document provides an overview of Raman spectroscopy. It discusses the discovery of Raman spectroscopy and how it is used to observe vibration, rotational, and other low-frequency modes in a system. It also describes key aspects of Raman spectroscopy including the instrumentation, principle, types of molecules that show Raman spectra, quantum and classical theories, and applications to analyze rotational, vibrational, and pure rotational Raman spectra of molecules. In summary, the document serves as an introduction to Raman spectroscopy and its use in chemistry to identify molecules based on their unique Raman fingerprint.
This document provides information about the "Raman and Luminescence Submicron Spectroscopy" Laboratory located at the V. Lashkaryov Institute of Semiconductor Physics, National Academy of Science, Ukraine. The laboratory contains several lasers, spectrometers, microscopes, and temperature control equipment used to perform Raman and luminescence spectroscopy and mapping on semiconductor nanostructures with submicron spatial resolution. The laboratory studies properties such as chemical composition, strain, temperature, carrier mobility and concentration in nanostructures for applications in microelectronics and optoelectronics. Team members and their areas of research interest are also listed.
This content was presented by me in Sathayabama University, India as an Invited talk in a DBT sponsored training program which covers the generalized about the Raman Scattering technique.
Raman spectroscopy is a technique that uses lasers to study vibrational and rotational modes in molecules. It relies on inelastic scattering, where the molecule scatters light at wavelengths different from the laser beam due to changes in polarizability during vibrations. The document discusses the principle, instrumentation, advantages and applications of Raman spectroscopy. It can be used to study liquids, solids, and gases without the interference of water. Common applications include structure elucidation, biological analysis, and quantitative/qualitative analysis.
This document summarizes Raman spectroscopy. It discusses the theory behind Raman scattering and how it differs from Rayleigh scattering. It describes the major components of a Raman spectroscopy system including the laser source, sample compartment, spectrometer, detector, and computer. It also outlines some applications of Raman spectroscopy in chemistry and solid-state physics such as molecular fingerprinting and materials characterization.
This document provides an overview of Raman spectroscopy. It discusses Raman scattering, which is the inelastic scattering of monochromatic light, usually from a laser, by molecules or atoms excited to higher vibrational or rotational energy levels. There are two types of Raman scattering: Stokes Raman scattering where the material absorbs energy and anti-Stokes Raman scattering where the material loses energy. Raman spectroscopy can be used to identify molecules and provide information about chemical bonds and molecular symmetry. It has various applications including medical use, detection of explosives, and investigation of historical documents.
Raman spectroscopy involves illuminating a sample with monochromatic light, usually from a laser in the visible, near infrared, or near ultraviolet range. Most of the scattered light is of the same wavelength as the incident light (Rayleigh scattering) but a small amount undergoes Raman scattering, resulting in light of different wavelengths. The shift in wavelength corresponds to changes in vibrational and rotational energy levels of molecules, providing a unique spectral fingerprint that can be used to identify molecular structures and compositions.
This document discusses Raman spectroscopy measurements of intensity and depolarization ratio. It explains that Raman spectroscopy measures molecular vibrations when light excites a sample's molecules. The Raman scattered light has parallel and perpendicular components relative to the incident light polarization. The depolarization ratio is the intensity ratio between the perpendicular and parallel components, indicating whether a vibration is symmetric. Factors like molecular symmetry and normal vibrational modes affect this ratio. A ratio below 0.75 indicates a totally symmetric vibration while 0.75 represents a non-symmetric vibration. The depolarization ratio helps interpret vibrations observed in Raman signals.
Raman spectroscopy analyzes the frequency shift of light scattered by matter due to molecular vibrations. Sir C.V. Raman discovered Raman scattering in 1928. Raman scattering occurs when photons interact with polarizable molecules, causing inelastic scattering where the photon's energy changes by the amount of a molecular vibration. This produces Stokes and anti-Stokes shifts from the incident light frequency. Resonance Raman spectroscopy enhances the Raman signal by matching the incident light frequency to an electronic transition.
This document provides an overview of Raman spectroscopy. It discusses how Raman spectroscopy works, including that it involves scattering of monochromatic light when it interacts with molecular vibrations, resulting in a shift in wavelength. It describes the discovery of the Raman effect by C.V. Raman and how Raman spectroscopy has advantages over infrared spectroscopy such as not being interfered with by water. The document also outlines the instrumentation used in Raman spectroscopy and applications such as analyzing inorganic and organic species.
Raman spectroscopy and infrared spectroscopy are both vibrational spectroscopy techniques but differ in their operating principles. Raman spectroscopy relies on inelastic scattering of monochromatic light, usually from a laser, while infrared spectroscopy relies on absorption of infrared light. Raman spectroscopy can be used to observe samples as solids, liquids, and gases without requiring preparation, and is suitable for aqueous solutions since water does not interfere with the signal. It has advantages over infrared spectroscopy for applications requiring minimal sample preparation and when analyzing biological samples in their native state.
Sir CV Raman was an Indian physicist who won the Nobel Prize in 1930 for his work on the Raman effect. He discovered that when light scatters from molecules, a small fraction of the light shifts to different wavelengths, which is now known as Raman scattering. Raman made many contributions in areas like X-ray diffraction, optics, and colloidal solutions. Raman spectroscopy uses the Raman effect to study materials by analyzing the scattering of monochromatic light. It provides a molecular fingerprint to identify compounds and detect molecular impurities. Both Raman and infrared spectroscopy are useful techniques to analyze materials, but Raman spectroscopy has advantages like avoiding interference from solvents and being able to detect IR-inactive modes.
Resonance Raman spectroscopy is a technique that enhances Raman scattering intensity when the laser excitation frequency matches an electronic transition of the compound being examined. This resonance effect can greatly increase the intensity of Raman bands, facilitating the study of compounds present at low concentrations. The intensity is directly proportional to the energy difference between the laser and electronic transition. The theory of resonance Raman is complex as the normal polarizability theory fails under resonance conditions. It allows selective study of specific parts of molecules and is useful for problems in biology and complexes materials.
Raman spectroscopy is a technique used for characterization and qualitative/quantitative analysis of research products. It provides a molecular fingerprint that can be used to identify samples. Raman spectroscopy is non-destructive and can be used to investigate artworks by identifying individual pigments and degradation products to learn about an artist's working methods. It also finds medical applications by allowing real-time monitoring of anesthetic and respiratory gas mixtures during surgery. The technique provides information on a sample's molecular structure, composition, and crystal orientation.
Introduction
The applications of microscopy in the forensic sciences are almost limitless. This is due in large measure to the ability of
microscopes to detect, resolve and image the smallest items of evidence, often without alteration or destruction. As a
result, microscopes have become nearly indispensable in all forensic disciplines involving the natural sciences. Thus, a
firearms examiner comparing a bullet, a trace evidence specialist identifying and comparing fibers, hairs, soils or dust, a
document examiner studying ink line crossings or paper fibers, and a serologist scrutinizing a bloodstain, all rely on
microscopes, in spite of the fact that each may use them in different ways and for different purposes.
The principal purpose of any microscope is to form an enlarged image of a small object. As the image is more greatly
magnified, the concern then becomes resolution; the ability to see increasingly fine details as the magnification is
increased. For most observers, the ability to see fine details of an item of evidence at a convenient magnification, is
sufficient. For many items, such as ink lines, bloodstains or bullets, no treatment is required and the evidence may
typically be studied directly under the appropriate microscope without any form of sample preparation. For other types of
evidence, particularly traces of particulate matter, sample preparation before the microscopical examination begins is
often essential. Types of Microscopes Used in the Forensic Sciences
A variety of microscopes are used in any modern forensic science laboratory. Most of these are light microscopes which
use photons to form images, but electron microscopes, particularly the scanning electron microscope (SEM), are finding
applications in larger, full service laboratories because of their wide range of magnification, high resolving power and
ability to perform elemental analyses when equipped with an energy or wavelength dispersive X-ray spectrometer.
Tapping into the Agri-Tourism Industry - Suggestions for Craft DistillersDianna Stampfler, CTA
Craft distillers are part of the overall agri-culinary-foodie-beverage tourism and tourism industry, where collaboration is key. #PureMichigan examples are provided.
This document summarizes a transportation company that has grown from a single truck in 1932 to a premier transportation provider in North America with over 80 years of experience. They offer customized and dedicated transportation solutions with a focus on partnerships, quality service, and minimizing risk while maximizing transportation investments. They have a consistent team of drivers with low turnover of less than 30% and focus on safety throughout the organization.
El documento presenta una imagen de una vista exterior de un espacio público. Se puede ver una plaza con árboles, bancos y personas caminando. El resumen ofrece una descripción general de la imagen sin entrar en detalles específicos.
how long will it all take? this finishes last week's conversation about how to craft your dissertation or thesis endgame and wraps it up with a bit of backwards mapping. More can be found on www.doctoralnet.com
Writing Plans help the writer get to the finish line on time! Discussing the concepts and a few tools proven to help, these slides backed up a DoctoralNet presentation on https://www.bigmarker.com/doctoralnet/Friday-PhD-How-To-Develop-Your-Writing-Plan
Real Estate Sole selling proposal for residential & commercial properties in ...Sunny Bakale
PUNE HOME BUY is a Pune based Sole Selling and brokerage firm. We provide services which include Sales, Marketing & CRM activity for any residential and commercial property in Pune. We are a team of highly trained professionals.
Virtual Holland Codes for Kids Career TestDr. Mary Askew
In 2013, Hollandcodes.com will launch a NEW virtual career test for elementary and middle school students. The Kid Career System uses self-by-step activities, career games for Kids, and kids activities for career choices to highlight Holland Codes. More details are available at Paintcareerswithcolors.com
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and
offering a wide range of dental certified courses in different formats.for more details please visit
www.indiandentalacademy.com
Dokumen tersebut membahas tentang proporsi, yaitu kalimat yang bernilai benar atau salah. Dibahas pula pengertian, contoh, dan cara mengkombinasikan proporsi menggunakan operator logika."
ECONOMIC PROBLEMS OF INFORMAL (UNORGANIZED) SECTOR PROFESSIONALS IN NAGPUR DI...IAEME Publication
Indian retail is dominated by a large number of small retailers consisting of the local kirana shops, owner-manned general stores, chemists, footwear shops, apparel shops, paan and beedi (local betel leaf and tobacco) shops, hand-cart hawkers, pavement vendors, etc. which together make up the so-called "unorganized retail" or traditional retail. The last few years have witnessed the entry of a number of organized retailers opening stores in various modern formats in metros and other important cities. Unorganized retailers normally do not pay taxes and most of them are not even registered for sales tax, VAT, or income tax. (Zia and Azam, 2013)
Retailing in India is predominantly unorganized. According to a survey by AT Kearney, an overwhelming proportion of the Rs. 400,000 crore retail markets are unorganized in India. In fact, only a Rs. 20,000 crore segment of the market is organized.
This document provides information on different types of microscopy techniques including bright field, dark field, phase contrast, and polarized light microscopy. It begins with explaining the basics of light and microscopy. It then describes each technique in more detail, including their principles, applications, advantages, and how they are set up optically. Bright field microscopy uses illumination and forms a dark image on a bright background. Dark field uses oblique illumination to see small particles as bright objects on a dark background. Phase contrast converts phase differences into contrast changes to see transparent specimens. Polarized light microscopy uses polarized filters to reveal structural details not otherwise seen.
[Norwegian] Presentasjon holdt på BartJS Meetup i Trondheim. Hør den i podcasten BartJS Podcast: https://soundcloud.com/bartjs/episode-0-a-podcast-awakens
Laura Fagan has a MSc in Pharmaceutical Quality Assurance and Biotechnology from DIT and a BSc in Biology from Maynooth University. She has relevant lab skills including aseptic technique, cell culture, instrumentation, and knowledge of GMP practices. She has experience in molecular biology techniques, microbiology, chemical analysis, and cell culture. Fagan has computer skills and instructional experience tutoring biology and chemistry. She held positions as a lab assistant at Maynooth University and NUI Maynooth providing lab support.
1) The document discusses staffing trends in India that will influence recruitment firms in 2016 and beyond. Key trends include a focus on building relationships with clients, candidates, and colleagues.
2) Top priorities for recruitment firms in India include growing their client base, being strategic partners to clients, and improving sourcing techniques. There is also increased focus on improving quality of hire.
3) Relationships are seen as important to driving business development and growth. Competition is increasing from both other recruitment firms and in-house recruiting. Developing a strong brand is seen as important to differentiating from competitors.
Maidana - Modification of particle accelerators for cargo inspection applicat...Carlos O. Maidana
As part of an accelerator based Cargo Inspection System, studies were made to develop a Cabinet Safe System by Optimization of the Beam Optics of Microwave Linear Accelerators of the IAC-Varian series working on the S-band and standing wave pi/2 mode. Measurements, modeling and simulations of the main subsystems were done and a Multiple Solenoidal System was designed.
This Cabinet Safe System based on a Multiple Solenoidal System minimizes the radiation field generated by the low efficiency of the microwave accelerators by optimizing the RF waveguide system and by also trapping secondaries generated in the accelerator head. These secondaries are generated mainly due to instabilities in the exit window region and particles backscattered from the target. The electron gun was also studied and software for its right mechanical design and for its optimization was developed as well. Besides the standard design method, an optimization of the injection process is accomplished by slightly modifying the gun configuration and by placing a solenoid on the waist position while avoiding threading the cathode with the magnetic flux generated.
The Multiple Solenoidal System and the electron gun optimization are the backbone of a Cabinet Safe System that could be applied not only to the 25 MeV IAC-Varian microwave accelerators but, by extension, to machines of different manufacturers as well. Thus, they constitute the main topic of this paper.
Laser guidance system for mobile robotstatsuyaarai
1) Researchers at the University of Tokyo propose a laser guidance system to guide small space robots and vehicles.
2) The system uses laser reflections detected by a receiver to estimate position and orientation errors and apply thruster and reaction wheel controls.
3) Simulations and 2D experiments validate the algorithm and show the system can guide an effector along a laser beam despite disturbances and temporary loss of the beam.
This experiment aims to determine Planck's constant using Wien's radiation method. Key components of the experimental setup include a tungsten filament bulb, mercury vapor lamp, spectrometer, diffraction grating, lenses, light dependent resistor (LDR), and power supplies. The procedure involves using the tungsten lamp to illuminate the diffraction grating and focus a color onto the LDR. The mercury vapor lamp is then used to determine the wavelength. Measurements of voltage, current and resistance are made and related through equations to calculate Planck's constant.
Instrumental Analysis: Spectrophotometric techniques can be used to analyze light-matter interactions. Key components of a spectrophotometer include light sources, monochromators to filter wavelengths, and detectors. Monochromators use diffraction gratings or prisms to separate wavelengths. Detectors like photomultipliers and photodiode arrays convert light signals into electrical signals. Spectrophotometers can be single or double beam, with double beam reducing errors. Fluorescence spectroscopy analyzes emission from electronically excited molecule, providing information about electronic structure.
This document contains 23 slides from a course on radar systems and the radar equation. It begins with an overview of key radar functions like detection, measurement, tracking and identification. It then provides details on the development of the radar range equation, covering topics like radar cross section, noise sources, system noise temperature and the effects of factors like target properties, radar characteristics, propagation medium and range. Examples are provided to demonstrate how modifying parameters like transmitter power, antenna diameter or range can impact radar performance. Charts show specifications for different types of search radars.
This document contains 20 slides from a lecture on radar systems and the radar equation. The slides cover topics such as the basic components of a radar system, definitions of terms like radar cross section, development of the radar range equation, sources of noise, and examples of how radar performance scales with different design parameters. Key aspects of the radar equation like transmitter power, antenna size, range, losses, and noise temperature are discussed across the slides.
Laser beam machining uses focused laser beams to cut, drill, mark, and modify a wide range of materials. It was introduced in the 1970s and is now commonly used in many industries. The key types of laser beam machining include cutting, drilling, marking, surface treatment, and welding of materials like plastics, ceramics, semiconductors, and metals. The document discusses the laser beam machining process and how various laser parameters like wavelength, spot size, intensity, and pulse width influence the machining and modification of materials.
The document discusses fast factorized back projection (FFBP) for processing circular synthetic aperture radar (CSAR) data. FFBP divides the synthetic aperture into sub-apertures and backprojects them onto polar grids. For CSAR, the polar grids for each sub-aperture must change orientation to follow the circular trajectory. Experimental results using real CSAR data from Germany's E-SAR system show FFBP adapted for CSAR provides high-accuracy reconstruction and is over 25,000 times faster than conventional backprojection.
The document discusses fast factorized back projection (FFBP) for processing circular synthetic aperture radar (CSAR) data. FFBP was adapted for CSAR by modifying the orientation of the polar grids used at each subaperture to follow the circular trajectory. Experimental results using real CSAR data from Germany's E-SAR system validated the FFBP-CSAR algorithm, showing high accuracy and significant speed improvements over conventional backprojection. The algorithm is now being used to process data from new multi-circular flight campaigns.
This document summarizes key concepts about laser beams and optical resonators:
1) Laser beam propagation can be described by the Helmholtz equation, with one solution being a Gaussian beam profile. The beam waist radius varies along the beam axis according to the Rayleigh range.
2) Optical resonators provide feedback to turn an amplifier into an oscillator. They contain mirrors between which light bounces and is amplified on each pass through the gain medium.
3) Resonator stability depends on the curvature and separation of the mirrors. Different resonator types support distinct transverse mode patterns within the beam.
This content presents for basic of Synthetic Aperture Radar (SAR) including its geometry, how the image is created, essential parameters, interpretation, SAR sensor specification, and advantages and disadvantages.
Fei sun chemical presentation 070114 2c [compatibility mode]inscore
Dr. Frank E. Inscore is a research and development professional with over 15 years of experience in chemistry, materials science, spectroscopy, and leadership of small start-up companies developing new technologies. His background includes a PhD in chemistry from the University of Arizona and postdoctoral research at the University of New Mexico, where he used techniques like X-ray absorption spectroscopy, magnetic circular dichroism, electronic absorption spectroscopy, and resonance Raman spectroscopy to study the structural and functional role of pyranopterin cofactors in molybdenum and tungsten enzymes. He has since worked in industrial research developing portable chemical analyzers and sensors using surface-enhanced Raman spectroscopy to identify chemicals and pathogens.
Magnetic resonance Magnetic Resonance Imaging to Assess Tissue Oxygenation an...nivedithag131
1) Electron paramagnetic resonance (EPR) spectroscopy detects species with unpaired electrons like free radicals, similar to how nuclear magnetic resonance (NMR) spectroscopy detects nuclei with magnetic moments.
2) EPR imaging can spatially resolve free radicals in biological systems like MRI does for protons, allowing for tissue oxygenation mapping via paramagnetic contrast agents.
3) Nitroxide radicals can provide redox status-dependent contrast in MRI, changing from paramagnetic to diamagnetic upon reduction, with potential tumor redox imaging applications.
The document provides an overview of silicon photomultipliers (SiPMs), including their structure, operation, performance characteristics, and potential applications. Some key points:
- SiPMs have an array of microcells that operate in limited Geiger-mode, providing high intrinsic gain comparable to PMTs but with lower excess noise.
- Performance metrics like gain, photon detection efficiency, dark counts, crosstalk, and timing characteristics depend on factors like microcell size, overvoltage, and temperature.
- Potential applications discussed include automotive LiDAR, flow cytometry, and radiation detection, where SiPMs could compete with or replace PMTs due to characteristics like compact size, stability, and
This document provides an overview of Raman spectroscopy. It begins with an introduction, explaining that Raman spectroscopy involves measuring the wavelength and intensity of inelastically scattered light from molecules. This scattered light occurs at shifted wavelengths corresponding to molecular vibrations.
It then provides a brief history of Raman spectroscopy and its development. The document outlines some key aspects of Raman spectroscopy, including that it is a vibrational spectroscopy that is complementary to infrared spectroscopy. Raman spectroscopy can be used to study samples with minimal preparation across various physical states.
The remainder of the document discusses various technical aspects of Raman spectroscopy in more detail, including classical theories, instrumentation components like lasers and filters, and conditions required for Raman scattering to occur. It provides examples
This document discusses various methods for calculating radar cross section (RCS), including the finite difference time domain method, method of moments, geometrical optics, physical optics, geometrical theory of diffraction, and physical theory of diffraction. It provides overviews and comparisons of each method, explaining their approaches and areas of applicability. The document also includes examples of RCS calculations and summaries of key points about specific methods.
This document discusses various methods for calculating radar cross section (RCS), including the finite difference time domain method, method of moments, geometrical optics, physical optics, geometrical theory of diffraction, and physical theory of diffraction. It provides overviews and comparisons of each method, explaining their approaches, assumptions, accuracy, and applicability to different target sizes and frequencies.
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.
This document provides an overview of Raman spectroscopy. It discusses the history and discovery of Raman scattering. The basic theory and classical description of Raman scattering from a diatomic molecule is explained. Factors that affect vibrational frequencies are outlined. The document also describes instrumentation components such as light sources, sample handling, filters, monochromators, detectors, and calibration standards. Variations of Raman spectroscopy including resonance Raman spectroscopy and surface-enhanced Raman spectroscopy are also summarized.
Module of fiber coupled diode laser based on 808nm single emitter combinationNaku Technology Co,. Ltd
Because of the good beam quality and heat dissipation of single emitter diode laser, it is more resuitable to be used in the source of electro-optic countermeasure. Aim at the responer curve of charge-coupled device (CCD) spectrum, 808nm single emitter is used as unitsource and 24 single emitters are divided into four groups. In order to increase the output power intensity, space sombination and polarization combination are used in the experiment. Combined beam is focused in an optical fiber through the focused lens group designed by ourself. All the single emittwes are connected inseries. When the drive current is 8.5A, 162W output power is obtained from a 300um fiber core with a numerical aperture of 0.22 at 808nm and coupling efficiency of 84%.
Module of fiber coupled diode laser based on 808nm single emitter combination
workshop_X_dec_2009_AF
1. 2009/12/07 Polarized and Polarimetric Raman spectroscopy and applications 1
Laboratoire de Physique des Interfaces et
des Couches Minces
Polarized and polarimetric Raman
spectroscopy and applications
A. Frigout, M. Richert, M. Lamy de la Chapelle &
R. Ossikovski
LPICM, Ecole Polytechnique, CNRS
alexandre.frigout@polytechnique.edu
3. 2009/12/07 Polarized and Polarimetric Raman spectroscopy and applications3
Motivation
• Objective : Fully exploit the capabilities of « classic »
characterization techniques (Raman and Rayleigh
scattering, fluorescence)
• Means: Combine Raman spectroscopy and related
techniques (Rayleigh scattering, fluorescence) with full
polarized light control (generation and analysis)
• Expected results : Stokes vector and Mueller matrix
measurements within « classic » characterization
techniques resulting in advanced characterization methods
4. 2009/12/07 Polarized and Polarimetric Raman spectroscopy and applications4
Experimental setup
• High Resolution Raman
spectroscopy
• Scanning probe
microscope
Oblique backscattering configuration
Piezo X,Y
Piezo Z
Microscope
Laser
grating
Notch filter
Detector
PSIA XE100 HORIBA JY Labram 800
X
Y
Z
5. 2009/12/07 Polarized and Polarimetric Raman spectroscopy and applications5
Polarization control:
1. half-wave plate
2. analyzer
(photos à ajouter)
Generation and analysis of linear polarization states (incident and bacscattered light)
Polarized Raman setup
spectrometer
Laser
objectives
Removable
mirror
Half wave
plate
Analyzer
Edge
filter
spectrometer
Laser
objectives
Removable
mirror
Half wave
plate
Analyzer
Edge
filter
6. 2009/12/07 Polarized and Polarimetric Raman spectroscopy and applications6
• Raman intensity : I ~ ∑|eS
T
Rjei|2
Rj : Raman tensor of the j phonon (3 for c-Si at 521 cm-1
)
eS : scattered polarization state (Analyzer A)
ei : incident polarization state (half wave plate P)
n
θ
ie
se
analyseur
A
Half wave plate
P
=
=
=
000
00
00
00
000
00
00
00
000
321 d
d
R
d
d
R
d
dR
azimuth
sample S
In the normal backscattering, the third phonon (LO) is the only
one wich can be observed !
Raman intensity depends on the polarization states eS and ei as well as
the sample azimuth !
Thoery of polarized Raman on crystals
7. 2009/12/07 Polarized and Polarimetric Raman spectroscopy and applications7
Principle : Shift of the optical Si-Si phonon (at 521 cm-1
)
caused by internal mechanical strain : Δw = f(σ)
Observations + model + corrections => stress
1. Model for Δω
(analytical ou FE )
2. Corrections pour
profil du faisceau,
pénétration (l) ???
3. Result:
s = g (Δω)0 200 400 600
0
10
20
30
40
50
60
70
Ramanintensity(a.u.)
Raman shift (cm
-1
)
Si-Si phonon
(3 degenerated modes:
TO1, TO2 et LO)
Rayleigh diffusion
Raman spectrum of c-Si
Stress analysis in Si by
Raman spectroscopy
8. 2009/12/07 Polarized and Polarimetric Raman spectroscopy and applications8
• In oblique configuration:
– Vary the azimuth sample or the incident polarization
– Fitting the intensity, frequency shift and the FWMH of the Si-Si line with a strain
model
80 nmsSi
SiGe
Si / SiGe structure:
MPa σ11
σ12
σ22
σ33
sSi 980 0 980 0
SiGe -650 0 -650 0
-20 0 20 40 60 80 100 120 140 160 180 200
509
515
516
517
Frequency(cm
-1
)
Sample azimuth (°)
FSiGe
FsSi
-20 0 20 40 60 80 100 120 140 160 180 200
2,8
3,0
3,2
3,4
3,6
3,8
4,0
4,2
4,4
4,6
4,8
FWHM(cm
-1
)
Sample azimuth (°)
strained-SiGe
strained-Si
Phonon position FWMHintensity
R. Ossikovski, Q. Nguyen, G. Picardi, J. Schreiber, J. Appl. Phys. 103, 093525 (2008)
R. Ossikovski, Q. Nguyen, G. Picardi, J. Schreiber, P. Morin, J. Raman Spectrosc. 39, 661 (2008)
bisotropic strain:
Strain measurement in
μRaman : strained Si/SiGe
Incident polarizationIncident polarization Incident polarization
σ11= σ22
9. 2009/12/07 Polarized and Polarimetric Raman spectroscopy and applications9
• Same experimental configuration but fitted with a biaxial
stress tensor: σ11 ≠ σ22
sSi
SiO2
substrat Si
Strained Si stripes (200nm width, 10nm thick): for CMOS transistor
channel
-20 0 20 40 60 80 100 120 140 160 180 200
3.2
3.3
3.4
3.5
3.6
3.7
3.8
FWMH
Polarization
-20 0 20 40 60 80 100 120 140 160 180 200
516.54
516.55
516.56
516.57
516.58
516.59
516.60
516.61
516.62
516.63
516.64
Shift
Polarization
sSipeakFWMH
sSipeakposition
Incident polarization
Biaxial strain : 1300 / 400 MPa (confirmed by XRays !)
Stress measurement in μRaman:
Si stripes on strained SiO2
Biaxial strain results in asymmetric polarization curves
10. 2009/12/07 Polarized and Polarimetric Raman spectroscopy and applications10
• Same experimental configuration.
-20 0 20 40 60 80 100 120 140 160 180 200
518.1
518.2
518.3
518.4
518.5
518.6
Experiment
Simulation
SipeakFWMH
Sipeakposition
Incident polarization
-20 0 20 40 60 80 100 120 140 160 180 200
5.20
5.25
5.30
Experiment
Simulation
Incident polarization
• SiNW optical image, 100x objective, 400nm diameter.
Fitted with an isotropic biaxial strain tensor with σ11 = σ22 = 450Mpa
and a (111) cristalline orientation
Stress measurement in
μRaman : SiNWs
11. 2009/12/07 Polarized and Polarimetric Raman spectroscopy and applications11
• Integration of a polarimeter in the HR-800
Raman spectrometer (from Horiba Jobin Yvon):
– Polarimetric calibration of the spectrometer
– Measurements of Stokes vector and Mueller matrix:
• in Rayleigh scattering regime (coherent illumination)
• of Raman bands (inelastic scattering)
• of fluorescence bands
Motivation for
polarimetric Raman
12. 2009/12/07 Polarized and Polarimetric Raman spectroscopy and applications12
−
−
−
=
=
−+
DG
yx
II
II
II
I
S
S
S
S
S
4545
0
3
2
1
0
• Description of polarized light (tottaly or not)
• Stokes vector:
• S0 : total intensity
• S1 : ligth polarized parallel
• S2 : light polarized perpendicular
• S3 : light circulary polarized
• DOP : fraction of polarized light
S / S0
Bijective
relationship
0
2
3
2
2
2
1
S
SSS
DOP
++
=
DOP < 1 : light partially polarized
DOP = 1 : light totally polarized
Polarimetry: Stokes
formalism
14. 2009/12/07 Polarized and Polarimetric Raman spectroscopy and applications14
• Determination of the physical charectiristics of the scattered light path
• Measurements of stokes vectors with differents inputs polarizations:
– A rotating linear polarizer
– A rotating quarter wave plate
• Stokes vectors obtained by Fast Fourier Transform
Laser source
Microscope Spectrometer
rotating
polarirzer
λ/2 rotating
plate
45° mirror
Laser source
Microscope Spectrometer
λ/4 rotating
plate
rotating
polarizer
λ/2 rotating
plate
45° mirror
Linear polarized light input circular polarized light input
Polarimetric Raman:
calibration approach
PSAPSA
15. 2009/12/07 Polarized and Polarimetric Raman spectroscopy and applications15
Stokes vector components vs input linear polarization
DOP
S1
S2
S3
Uncalibrated Raman spectrometer
response
Incident polarization Incident polarization
Incident polarizationIncident polarization
• Experimentals results:
– DOP varies between 0.8 and 1.1
– S1 and S2 have sinusoïdal trends but
do not fit with cosine and sine
– S3 varies between -0.5 and 0.4
• In theory:
– DOP = 1
– S1, S2 exhibit a sinusoïdal trend
– S3 = 0
The system is not passive with
respect to the polarization!
Simulated stokes vector
measured stokes vector
Laser source
Microscope Spectrometer
rotating
polarirzer
λ/2 rotating
plate
45° mirror
16. 2009/12/07 Polarized and Polarimetric Raman spectroscopy and applications16
Poincaré sphere representation
of the uncalibrated response
17. 2009/12/07 Polarized and Polarimetric Raman spectroscopy and applications17
IRaw
FFT {α, θ, Δ, D, R}
S = MΔ
-1
MD
-1
MR
-1
SRaw
Depolarizer
Diattenuator
Retarder
DOP ~ 1
S3 ~ 0
• Reasons of this modelisation:
– Depolarizer : DOP close to 1
– Diattenuator : uniform distribution of the polarization state on the ecuador
– Retarder : cancel the S3, bring the plane of the polarization states on the ecuador
• Recursive function with α, θ and Δ as initial conditions
– Calculation of R and D
• R, D and Δ have the sames axes (our reference frame), in that case their matrices
commute
Scattered light path
modeling
19. 2009/12/07 Polarized and Polarimetric Raman spectroscopy and applications19
Poincaré sphere representation of
the calibrated system response
• Polarization states close to the
ecuador and uniformly distributed
• Missmatch between first and
second loop of the polarization
states:
– misalignement of the retarder with
respect to the laser beam
20. 2009/12/07 Polarized and Polarimetric Raman spectroscopy and applications20
Stokes vector components vs input elliptical polarization
Laser source
Microscope Spectrometer
λ/4
P
45°
mirror
Response to an elliptical
polarization input
σS = < | Sexp- Stheo | >
= 10-2
[ 2.39 3.12 5.71 ]
Incident polarization Incident polarization
Incident polarizationIncident polarization
PSA
Simulated stokes vector of a
retarder plates (adjustment :
R = 74.03° theta Sin = ???)
measured stokes vector
21. 2009/12/07 Polarized and Polarimetric Raman spectroscopy and applications21
Poincaré sphere system
response
• Polarization states close to
the simulated curve
• Mismatch between first and
second loop of the
polarization states:
– misalignement of the retarder
with respect to the laser beam
measured stokes vector
Simulation with R = 74.03°
Measurement MM16:
R = 74.3°
=> Good agreement
Input : retarder plate at different azimuths
22. 2009/12/07 Polarized and Polarimetric Raman spectroscopy and applications22
DOP
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1
P S P S P S
514 nm 458nm
633 nm
S1
-1
-0.5
0
0.5
1
P S P S P S
514 nm 458nm633 nm
S2
-1
-0.5
0
0.5
1
P S P S P S
514 nm 458nm633 nm
S3
-1
-0.8
-0.6
-0.4
-0.2
0
0.2
0.4
0.6
0.8
1
P S P S P S
514 nm 458nm633 nm
Stokes-Rayleigh measurement
of STM gold tips
• DOP : competition
between Rayleigh
regime scattering
(458nm) & plasmonic
excitation (633nm)
• A « strong » S3
component at 633 nm :
resulting from
plasmonic excitation (?)
Stokes vector components vs wavelength
Characterization of near field probes through their polairzation response
tiptip
23. 2009/12/07 Polarized and Polarimetric Raman spectroscopy and applications23
Conclusion & outlook
• Polarization control is an important « degree of freedom » that
can be advantageously exploited in scattering and spectroscopic
techniques (Rayleigh, Raman, fluorescence…)
• Polarization control is applied with success to industrial
applications of Raman such as stress characterization in
semiconductors
• Extension from polarized to polarimetric Rayleigh and Raman
scattering opens up the way to novel measurement opportunities
(Mueller-Rayleigh, Mueller-Raman matrices) and applications
(plasmonics)
WE ARE ONLY IN THE BEGINNING,
THE MOST EXCITING IS TO COME!