Showing papers on "Light scattering published in 1980"
TL;DR: New and thoroughly documented Mie scattering algorithms that result in considerable improvements in speed by employing more efficient formulations and vector structure are described.
Abstract: Scattering of electromagnetic radiation from a sphere, so-called Mie scattering, requires calculations that can become lengthy and even impossible for those with limited resources. At the same time, such calculations are required for the widest variety of optical applications, extending from the shortest UV to the longest microwave and radar wavelengths. This paper briefly describes new and thoroughly documented Mie scattering algorithms that result in considerable improvements in speed by employing more efficient formulations and vector structure. The algorithms are particularly fast on the Cray-1 and similar vector-processing computers.
1,465 citations
TL;DR: A theory for surface enhanced Raman scattering (SERS) is developed in this paper, where the surface is modeled as a hemispheroid protruding from a conducting plane.
Abstract: A theory for surface enhanced Raman scattering (SERS) is developed Effects due to realistic surface geometry and dielectric properties are included Three sources of enhanced Raman scattering are noted: the image dipole enhancement effect, the increase of local field (’’lightning rod’’ effect), and the resonant excitation of surface plasmons The surface is modeled as a hemispheroid protruding from a conducting plane, although other models are considered The spherical limit is discussed in some detail and molecular orientation effects are considered Cross sections for Mie, Rayleigh, and Raman scattering are derived
978 citations
TL;DR: Use of lasers has revolutionized the study and applications of radiation pressure, and it is now possible to optically accelerate, slow, stably trap, and manipulate micrometer-sized dielectric particles and atoms.
Abstract: Use of lasers has revolutionized the study and applications of radiation pressure. Light forces have been achieved which strongly affect the dynamics of individual small particles. It is now possible to optically accelerate, slow, stably trap, and manipulate micrometer-sized dielectric particles and atoms. This leads to a diversity of new scientific and practical applications in fields where small particles play a role, such as light scattering, cloud physics, aerosol science, atomic physics, quantum optics, and high-resolution spectroscopy.
559 citations
TL;DR: These results simulate those observed at roughened silver electrodes and suggest that the mechanism of SERS at those electrodes may resemble the electromagnetic mechanism elucidated here, and predict that comparable effects should be observed for fluorescent scattering.
Abstract: A model for Raman scattering by a molecule adsorbed at the surface of a spherical particle is articulated by treating the molecule as a classical electric dipole. This follows Moskovits’s suggestion [
J. Chem. Phys.69,
4159 (
1978)] and the experiments by
Creighton
[
J. Chem. Soc. Faraday Trans. II,
75,
790 (
1979)] that such a system may exhibit SERS similar to that at roughened electrode surfaces. The molecule is stimulated by a primary field comprised of the incident and near-scattered fields. Emission consists of the dipole field plus a scattered field, each at the shifted frequency. Addition of feedback terms between the dipole and the particle makes only a negligible contribution to the fields. For pyridine adsorbed at the surface of a silver sphere, the 1010-cm−1 band is enhanced by ~106 if the radius is much less than the wavelengths and the excitation wavelength is ~382 nm, a wavelength for which the relative refractive index of silver is close to
m=2i. Detailed results are given for the effect, upon the angular distribution and the polarization of the Raman emission, of particle size, distance from the surface, excitation wavelength, and location of the molecule upon the surface. These results simulate those observed at roughened silver electrodes and suggest that the mechanism of SERS at those electrodes may resemble the electromagnetic mechanism elucidated here. We predict that comparable effects should be observed for fluorescent scattering.
556 citations
26 Mar 1980
TL;DR: A computer model is presented which allows the image components of an underwater camera system to be computed and basic quantities such as contrast transmittances and signal to noise ratio can be calculated over the entire field of view of the camera.
Abstract: A computer model is presented which allows the image components of an underwater camera system to be computed. Input parameters to the model are system geometry, source properties, and water optical properties. Output products are the irradiances due to non scattered object light, scattered object light and backscattered light. From these basic quantities other useful parameters such as contrast transmittances and signal to noise ratio can be calculated over the entire field of view of the camera. Sample calculations are presented.
339 citations
TL;DR: The angular scattering behavior of spheroids is found to be greatly different from that of spheres for side scattering to backscattering directions and the linear polarization and depolarization are discussed in application to scattering in the earth and planetary atmospheres.
Abstract: Light scattering properties of an assembly of randomly oriented, identical spheroidal particles are studied. A computation scheme has been developed to integrate the solution of Asano and Yamamoto for scattering from a homogeneous spheroid over all the particle orientations. The extinction and scattering cross sections, asymmetry factor, and scattering matrix elements are calculated for randomly oriented prolate and oblate spheroids and compared with both calculations for spheres and laboratory measurements, The scattering cross section, single scattering albedo, and asymmetry factor of spheroids tend to be larger than those for spheres of the same volume. The normalized scattering matrix has a symmetrical form with six independent elements. The angular scattering behavior of spheroids is found to be greatly different from that of spheres for side scattering to backscattering directions. In general, prolate and oblate spheroids of the same shape parameter have similar angular scattering patterns. The angular distribution of scattered intensity is characterized by strong forward scattering and weak backscattering. The linear polarization tends to be positive at intermediate scattering angles. The linear polarization and depolarization are discussed in application to scattering in the earth and planetary atmospheres.
324 citations
TL;DR: In this paper, a semi-empirical theory is developed for evaluating the interaction of randomly oriented, nonspherical particles with the total intensity component of electromagnetic radiation, which is used when the particle size parameter x (ratio of particle circumference to wavelength) is less than some upper bound x sub zero (about 5).
Abstract: A semiempirical theory is developed which is based on simple physical principles and comparisons with laboratory measurements. The ultimate utility of this approach rests on its ability to successfully reproduce the observed single-scattering phase function for a wide variety of particle shapes, sizes and refractive indices. This approximate theory is developed for evaluating the interaction of randomly oriented, nonspherical particles with the total intensity component of electromagnetic radiation. Mie theory is used when the particle size parameter x (ratio of particle circumference to wavelength) is less than some upper bound x sub zero (about 5). For x greater than x sub zero, the interaction is divided into three components: diffraction, external reflection and transmission. The application of the theory is illustrated by considering the influence of the shape of tropospheric aerosols on their contribution to the earth's global albedo.
312 citations
TL;DR: In this article, the authors focus on the depolarized Rayleigh and Raman scattering from liquids composed of small, rigid molecules; however, they also refer to the results of other experiments (NMR, IR, and molecular dynamics) that provide complementary informentation.
Abstract: In this review we focus attention primarily upon the depolarized Rayleigh and Raman scattering from liquids composed of small, rigid molecules; however, we also refer to the results of other experiments (NMR, IR, and molecular dynamics) that provide complementary infor mation. Even within this limited framework we do not provide a comprehensive review of the recent literature but rather we select certain topics that are of particular interest to us and where important changes have recently occurred. We have attempted to integrate the information from different sources and to provide a critical (and clearly personalized) analysis. Several excellent reviews of various aspects of this subject have appeared since the last review in this series (1). In particular the text on light scattering by Berne & Pecora (2), reviews on vibrational dephasing and energy relaxation by Oxtoby (3,4), the articles on rotational relaxation by Steele (5) and Griffiths (6), and the review of collision-induced scattering by Tabisz (7) discuss the techniques and physical principles involved. The up-to-date treatment of many topics in these sources has helped us restrict our choice of subject matter. The Raman and depolarized Rayleigh spectra monitor the fluctua tions in the polarizability density that arise from the modulation of the intrinsic (gas phase) and the interaction-induced polarizabilities of the molecules by the molecular motion. If there were no interaction-induced polarizability the shape of the depolarized Rayleigh spectrum (DRS)
276 citations
TL;DR: The first small-angle X-ray scattering study of Triton X-100 at different temperatures and ionic strengths in order to measure molecular weight, shape, and hydration of this nonionic surfactant is described in this paper.
Abstract: This work describes the first small-angle X-ray scattering study of Triton X-100 at different temperatures and ionic strengths in order to measure molecular weight, shape, and hydration of this nonionic surfactant. The X-ray scattering study is performed on the detergent at different electron density contrast by varying the electron density of the solvent by addition of glycerol or thallium nitrate. This study detects, on the basis of small-angle X-ray scattering experiments and by using a different contrast between the Triton X-100 micelles and the applied solvent, the hydrophobic core when using the assumption of a 2-step density level within the molecule. Furthermore, quasielastic light scattering measurements of aqueous solutions of Triton X-100 were performed which allow measurement of the diffusion coefficient. 30 references.
271 citations
TL;DR: By using large off-axis scatter detection angles, the measurement of the droplet size and velocity distributions in relatively dense spray environments is made possible.
Abstract: A method is described for obtaining real-time in situ size and velocity measurements of spherical particles or droplets using crossed-beam interferometry. The optical arrangement, which is similar to a dual-scatter laser Doppler velocimeter (LDV), consists of two laser beams focused to a crossover region. Droplets passing through the focal volume scatter light to the collecting lens situated at some off-axis angle. The dual-beam light scatter is analyzed by the geometric optics theory to relate the scattered fringe pattern to the droplet diameter. Because the droplet size measurement is based on the relative phase shift between the two light waves passing through it, the method is independent of the incident intensity, droplet absorption, or absolute scattering intensity. Experimental measurements of monodisperse droplet streams show good agreement with the theory. The technique can be applied to spray-droplet measurements over the size range of 3 μm to 5 mm. By using large off-axis scatter detection angles, the measurement of the droplet size and velocity distributions in relatively dense spray environments is made possible.
TL;DR: In this article, a method for calibrating photodetectors based on some characteristics of the statistics of the field of spontaneous parametric light scattering is described, and a phenomenological theory of parametric scattering is used to demonstrate that photons are only emitted in pairs.
Abstract: A description is given of a method for calibrating photodetectors based on some characteristics of the statistics of the field of spontaneous parametric light scattering. A phenomenological theory of parametric scattering is used to demonstrate that photons are only emitted in pairs. It is shown that, in principle, a priori information on the two-photon character and directionality of parametrically scattered light can be used for absolute calibration of photodetectors operated both in the analog linear regime and in the discrete photoelectron pulse counting regime.
TL;DR: In this article, the authors applied the dynamical model of rotational diffusion of rod-shaped molecules in a conical volume to the calculation of time autocorrelation functions of 1st and 2nd order spherical harmonic functions of the rod's orientation angles.
Abstract: The dynamical model of rotational diffusion of rod‐shaped molecules in a conical volume is applied to the calculation of time autocorrelation functions of 1st and 2nd order spherical harmonic functions of the rod’s orientation angles. Numerical results are obtained for the various correlation functions as a function of the polar angle ϑ0 within which the molecule’s axis is confined. Applications to dielectric relaxation, dynamic light scattering, and fluorescence depolarization experiments are pointed out.
TL;DR: In this article, collision-induced (CI) effects to the lowest order in the dipole-induced dipole approximation have been investigated, including deviations from the Lorentz-Lorenz (Claus-Mosotti) relation, changes in the spectral moments of both Rayleigh an Raman bands and in their depolarization ratios.
Abstract: Molecular dynamics calculations of the Rayleigh and Raman light scattering properties of atom–atom Lennard‐Jones fluids (’’N2’’, ’’O2’’, ’’Cl2’’, and ’’CO2’’) have been made, including collision‐induced (CI) effects to lowest order in the dipole‐induced dipole approximation. CI effects are shown to result in deviations from the Lorentz–Lorenz (Claus–Mosotti) relation, changes in the spectral moments of both Rayleigh an Raman bands and in their depolarization ratios. Where possible, the predicted magnitudes are compared with experiment. Calculated CI influences on the effective molecular polarizability are compared with theoretical estimates based on the superposition approximation. The importance of isotropic CI light scattering in molecular fluids is indicated. Finally, we discuss the separability of orientational and CI contributions to depolarized spectra.
TL;DR: In this article, a simplified method for measuring the effective photon lifetime in an optical resonator was developed, which requires the passage of a modulated cw laser beam through the resonator and the measurement of the resultant shift in the phase of the transmitted intensity.
Abstract: A simplified method for measuring the effective photon lifetime in an optical resonator was developed. The technique requires the passage of a modulated cw laser beam through the resonator and the measurement of the resultant shift in the phase of the transmitted intensity. The method not only permits a quick and precise measurement of the mirror reflectances, but also permits these measurements to be in situ. Such an on-the-spot evaluation capability should be extremely useful in applications ranging from the investigation of new laser systems to the development of improved optical coatings. The method is also sensitive to the effects of absorption, scattering, and transmission from elements in the cavity. Cavity losses <100 ppm were detected.
TL;DR: It was found that the angular scattering calculated using the experimentally obtained roughness spectral density function agreed remarkably well with the measured angular scattering data.
Abstract: Measurements of angular scattering due to surface roughness were taken from a 24-layer dielectric mirror and compared to theory. In addition, the top surface roughness of the multilayer stack is analyzed from Talystep profilometer measurements. These roughness data are used to obtain a roughness spectral density function to be used in a vector multilayer scattering theory. The theory uses three multilayer stack models to incorporate possible effects of different degrees of correlation between interfaces of the stack. It was found that the angular scattering calculated using the experimentally obtained roughness spectral density function agreed remarkably well with the measured angular scattering data. This is especially true if care is taken to differentiate between particulate and roughness scattering. For the sake of comparison, the angular scattering from an aluminum film is also given, and differences from scattering from the multilayer mirror are noted.
TL;DR: Estimates of the real and imaginary parts M′ and M″ of the longitudinal bulk modulus have been made for the first time and offer opportunities for probing the lens and its proteins topographically as a function of growth.
Abstract: Brillouin spectra of biological systems may ultimately be related to their intrinsic molecular properties. In some instances the optical properties may be associated with the elastic ones and ultimately with the force constants of the molecules involved1,2. In the present work we have used a triple-pass Fabry–Perot interferometer to measure Brillouin light scattering spectra for refractive tissues of the eye, including cornea, capsule and lens. Combined with corresponding measurements of density, estimates of the real and imaginary parts M′ and M″ of the longitudinal bulk modulus have been made for the first time. Measurements have extended over four classes of vertebrate: Mammalia, Aves, Pisces and Amphibia; only small differences have been found between the various samples of cornea, whereas marked differences occur between the different lenses. Hence this account concentrates largely on the latter. The implications of this work lie not so much at the opthalmological level as at the macromolecular and offer, in conjunction with other scattering techniques, opportunities for probing the lens and its proteins topographically as a function of growth.
TL;DR: In this article, a two-parameter phase function for highly anisotropic angular scattering distributions is described, which has a convenient analytic representation since it is the generating function for the Gegenbauer polynomials.
Abstract: A two-parameter phase function is described for highly anisotropic angular scattering distributions. The phase function has a convenient analytic representation since it is the generating function for the Gegenbauer (or ultraspherical) polynomials. Sample calculations illustrate the large variety of forward-to-backward scattering amplitudes and shapes that can be fit with the two parameters. Illustrative phase functions are given that approximate light scattering distributions predicted for several biological and atmospheric specimens from Rayleigh-Gans and Mie models. A suggested classification scheme for size and refractive index of microparticles in human blood is presented as a potential application of the phase function with two parameters.
Journal Article•
TL;DR: The scattering factor shows a marked increase in patients with early cataracts even if their visual acuity is not affected, and is a direct measure of the intraocular light scattering.
Abstract: A method is presented for quantitative measurements of the glare effect of light scattered in the ocular media The contrast sensitivity function is measured with a television display system A bright light source is introduced into the field of vision, and the resultant decrease in contrast sensitivity is mea-ured It is further used to calculate a scattering factor which is a direct measure of the intraocular light scattering The scattering factor shows a marked increase in patients with early cataracts even if their visual acuity is not affected
TL;DR: In this paper, a new method has been proposed for the interpretation of the dynamic scattering experiments in terms of the initial slope,,Q, of In S(q, t).
TL;DR: In this paper, the contribution of elastic photon scattering from an atom due to scattering off the bound atomic electrons (Rayleigh scattering) is calculated and compared with other theories, particularly the form-factor approximation.
Abstract: We calculate the contribution to elastic photon scattering from an atom due to scattering off the bound atomic electrons (Rayleigh scattering). We compare predictions resulting from our numerical evaluation of the relativistic second-order $S$ matrix in a screened central potential with other theories, particularly the form-factor approximation. We give a prescription for accurate $O(1%)$ evaluation of total-atom Rayleigh amplitudes (summed over electrons) and present sample tabulations for lead ($Z=82$) for energies of experimental interest in the range from 22.1 to 2750 keV. Based on our prescription we compare elastic-scattering cross sections using Rayleigh amplitudes with selected experiments and are able to remove the large factor-of-two discrepancies previously reported.
TL;DR: In this paper, the authors derived explicit expressions for multiple-scattering effects under assumptions which are usually fulfilled in small-angle scattering and used them to evaluate quantitatively distortions of scattering patterns caused by multiple scattering.
Abstract: Analytical explicit expressions have been derived for multiple-scattering effects under assumptions which are usually fulfilled in small-angle scattering. The expressions are used to evaluate quantitatively distortions of scattering patterns caused by multiple scattering. The distortions are discussed in terms of changes of the forward-scattering cross section, the radius of the gyration, the integrated intensity, the Porod region and Porod constant. In addition, the analytical expressions have been used to calculate the scattering cross section of the sample from scattering patterns which are strongly affected by multiple scattering.
PARC1
TL;DR: In this paper, a new method of obtaining Raman spectra from a very thin highly absorbing films (α≳105 cm−1) is described, which is termed interference enhanced Raman scattering (IERS) and theoretically produces a gain in the scattered intensity of 10−103 (depending on the optical constants of the material) over that expected from a thick sample using the conventional Raman backscattering configuration.
Abstract: A new method of obtaining Raman spectra from a very thin highly absorbing films (α≳105 cm−1) is described. The technique which is termed interference enhanced Raman scattering (IERS) is shown theoretically to produce a gain in the scattered intensity of 10–103 (depending on the optical constants of the material) over that expected from a thick sample using the conventional Raman backscattering configuration. The potential of the method is demonstrated experimentally using tellurium, and a gain of 20 is obtained.
01 Sep 1980
TL;DR: In this paper, Shifrin's method applied to Scattering by Tenuous Non-Spherical Particles is applied for Scattering of Radiation by a Large Particle with a Rough Surface.
Abstract: 1: Introduction.- Some Remarks on Science, Scientists, and the Remote Sensing of Particulates.- Focusing in on Particle Shape.- 2: User Needs.- Sensing Ice Clouds from Satellites.- Lidar Visibility Measurements.- Non-Spherical Particle Scattering: Air Force Applications.- Particles Producing Strong Extinction in the Infrared.- 3: Specific Particle Descriptions.- Shape of Raindrops.- Atmospheric Ice Crystals.- Physical Properties of Atmospheric Particulates.- Some Characteristics of the Antarctic Aerosol.- Examples of Realistic Aerosol Particles Collected in a Cascade Impactor.- 4: Theoretical Methods.- Absorption by Small Regular Non-Spherical Particles in the Rayleigh Region.- Infrared Absorption Spectra of Non-Spherical Particles Treated in the Rayleigh-Ellipsoid Approximation.- Scattering by Non-Spherical Particles of Size Comparable to a Wavelength: A New Semi-Empirical Theory.- Scattering and Absorption by Wavelength Size Discs.- Perturbation Approach to Light Scattering by Non-Spherical Particles.- Exact Calculations of Scattering from Moderately-Nonspherical Tn-Particles: Comparisons with Equivalent Spheres.- Surface Waves in Light Scattering by Spherical and Non-Spherical Particles.- Shifrin's Method Applied to Scattering by Tenuous Non-Spherical Particles.- Energy Conservation: A Test for Scattering Approximations.- Electromagnetic Scattering from Two Identical Pseudospheres.- Absorption by Particle Edges and Asperities.- On the Scattering from Arbitrarily Shaped Inhomogeneous Particles - Exact Solution.- Light Scattering by Hexagonal Columns and Plates.- Scattering of Radiation by a Large Particle with a Rough Surface.- 5: Experimental Methods.- The Microwave Analog Facility at SUNYA: Capabilities and Current Programs.- Observation of Light Scattering from Oriented Non-Spherical Particles Using Optical Levitation.- The Effect of an Electric Field on the Backscattered Radiance of a Single Water Droplet.- In-Situ Light Scattering Techniques for Determining Aerosol Size Distributions and Optical Constants.- Problems in Calibrating a Polar Nephelometer.- 6: Experimental Results.- Extinction Signatures of Non-Spherical/Non-Isotropic Particles.- Scattering by Particles of Non-Spherical Shape.- Phase Matrix Measurements for Electromagnetic Scattering by Sphere Aggregates.- Reflectivity of Single Micron Size Irregularly Shaped Dust Grains.- Biological Particles as Irregularly Shaped Scatterers.- 7: Inversion and Information Content.- Inference of Scatterer Size Distribution from Single Scattering Matrix Data.- Light Scattering by Irregularly Shaped Particles Versus Spheres: What Are Some of the Problems Presented in Remote Sensing of Atmospheric Aerosols?.- Participants.
TL;DR: In this paper, a method for finding the electromagnetic fields scattered or guided by lossy dielectric gratings having arbitrary profiles is presented, which unifies the treatment of both perpendicular (TE) and parallel polarizations by expressing the fields in terms of two coupled first-order differential equations.
Abstract: Based on an exact solution of the pertinent boundary-value problem, a method is presented for finding the electromagnetic fields scattered or guided by lossy dielectric gratings having arbitrary profiles. This method unifies the treatment of both perpendicular (TE) and parallel (TM) polarizations by expressing the fields in terms of two coupled first-order differential equations. Their solution is obtained by resorting to difference equations in conjunction with the algorithm of Adams–Moulton, which easily leads to accurate results for a large variety of practical problems. To illustrate the application of this approach, quantitative results are presented for the scattering of plane waves by lossy corrugated structures and for the guiding of (leaky) surface waves by triangular gratings with symmetric or asymmetric profiles.
01 Jan 1980
TL;DR: In this paper, the authors used quasi-elastic light scattering in the measurement of the motion of Flagellated Algae and showed that it can be used to study intermicellar interactions.
Abstract: I: Colloid and Polymer Solutions.- Some Experiments Using Quasielastic Light Scattering.- Diffusion Coefficients in Colloidal and Polymeric Solutions.- On the Long Time Diffusion of Interacting Brownian Particles.- The Application of Brownian Dynamics to Photon Correlation Spectroscopy.- Light Scattering From Sterically Stabilized Silica Particles.- Depolarized Light Scattering from Concentrated Particle Suspensions.- Intramolecular Motion of Polystyrene.- II: Micelles, Thin Films and Biological Macromolecules.- Quasielastic Light Scattering Study of Intermicellar Interactions.- Stability and Fusion of Vesicles.- Light Scattering by Water in Oil Microemulsions.- Dynamic Light Scattering from Thin, Free, Liquid Films.- Techniques for Light Scattering from Hemeglobin.- Quasi-Elastic Light Scattering in the Measurement of the Motion of Flagellated Algae.- III: Phase Transitions and Hydrodynamic Instabilities.- Hydrodynamic and Critical Phenomena: Rayleigh-Benard Instability as a Critical Phenomenon and Critical Fluctuations Reduced by Shear, Both Related to Mean Field Behavior.- Interface Fluctuations of Growing Ice Crystals.- Buoyancy Driven Instabilities in Two Component Systems.- Thermodynamic Analysis of Inverted Bifurcation.- IV: Forced Raylexgh Scattering.- Forced Rayleigh Light Scattering in Fluids.- Study by Forced Rayleigh Scattering of Thermal Excitations in a Stratified Liquid Layer.- Forced Rayleight Scattering as Optoelastic Probe in SA Liquid Crystals.- Forced Rayleigh Scattering in a Critical Binary Liquid Mixture.
01 Jan 1980
TL;DR: This review includes experimental and theoretical work on absorption and scattering of light by chiral macromolecules, and theoretical methods that relate the absorption and circular dichroism of a polymer or aggregate to the optical proper ties of its constituent parts.
Abstract: This review includes experimental and theoretical work on absorption and scattering of light by chiral macromolecules. All molecules absorb light, but only chiral (handed) molecules show a preferential absorption for right or left circularly polarized light. This phenomenon of circular dichroism (CD) has been very useful in characterizing any chiral aggre gate of chromophores-including proteins, nucleic acids, and their complexes. We discuss theoretical methods that relate the absorption and circular dichroism of a polymer or aggregate to the optical proper ties of its constituent parts. The experimental data reviewed is limited essentially to nucleic acids, for lack of space. Two new experimental methods that are particularly useful for mac romolecules or for systems that scatter a significant fraction of the incident light are fluorescence-detected circular dichroism and circular intensity differential scattered light. Fluorescence-detected circular di chroism (FDCD), as the name implies, used the intensity of the fluores cence emitted to monitor the intensity of the light absorbed (167). This method provides two main advantages: (a) The spectrum of a complex system containing many chromophores, but only a few fluorophores is greatly simplified, and (b) scattering artifacts, which plague circular dichroism studies using transmitted light measurements, are partly avoided by use of fluorescence detection. The theory (159, 160) and
TL;DR: The Raman spectra of chemisorbed cyanide on a silver (110) surface exposed to air show an enhanced Raman cross section for the C-N stretch vibrations as discussed by the authors.