Edison, NJ, United States
Edison, NJ, United States

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Garcia-Caurel E.,Ecole Polytechnique - Palaiseau | De Martino A.,Ecole Polytechnique - Palaiseau | Gaston J.-P.,Horiba Jobin Yvon S.A.S. | Yan L.,HORIBA Scientific Inc.
Applied Spectroscopy | Year: 2013

This article provides a brief overview of both established and novel ellipsometry techniques, as well as their applications. Ellipsometry is an indirect optical technique, in that information about the physical properties of a sample is obtained through modeling analysis. Standard ellipsometry is typically used to characterize optically isotropic bulk and/or layered materials. More advanced techniques such as Mueller ellipsometry, also known as polarimetry in the literature, are necessary for the complete and accurate characterization of anisotropic and/or depolarizing samples that occur in many instances, both in research and in real-life activities. In this article, we cover three main subject areas: Basic theory of polarization, standard ellipsometry, and Mueller ellipsometry. The first section is devoted to a short, pedagogical introduction of the formalisms used to describe light polarization. The second section is devoted to standard ellipsometry. The focus is on the experimental aspects, including both pros and cons of commercially available instruments. The third section is devoted to recent advances in Mueller ellipsometry. Application examples are provided in the second and third sections to illustrate how each technique works.


Adar F.,HORIBA Scientific Inc.
Spectroscopy (Santa Monica) | Year: 2015

There is growing interest in using Raman as a spectroscopic probe of biological systems based on its high information content, its compatibility with an aqueous environment, and the spatial resolution that is consistent with physical optics (as good as ∼0.5 μm). Sampling hardware innovations in recent years such as cell sampling in a lab-on-a-chip and progress in the design of Raman endoscopes are enabling new realms of measurement. The integration of multivariate analysis into Raman mapping has enabled information to be teased out that might not be seen by the human eye. In addition, there are nonlinear techniques such as coherent anti-Stokes Raman scattering (CARS) and stimulated Raman scattering (SRS) that provide images more rapidly. For those who are contemplating jumping into this arena, this column will summarize where the field is now and what might be some pitfalls. © 2015 Advanstar Communications, Inc. All rights reserved.


Tuschel D.,HORIBA Scientific Inc.
Spectroscopy (Santa Monica) | Year: 2016

Photoluminescence can provide information about the composition and solidstate structure of a material. The high spectral resolution of a Raman spectrometer can be useful in performing photoluminescence spectroscopy of solidstate materials, particularly when the emission spectra consist of narrow bands or even lines. Having the capability to perform photoluminescence and Raman spectroscopies simultaneously with the same instrument is advantageous, especially when studying twodimensional (2D) crystals. When used to perform photoluminescence spectroscopy, the Raman spectrometer becomes two instruments in one. © 2016 Advanstar Communications, Inc.


Mamedov S.,HORIBA Scientific Inc.
Materials Research Society Symposium Proceedings | Year: 2015

TiO2 nanopowdcrs obtained using different methods with the mean size of 5, IS, and 30 nm have been investigated by Raman spectroscopy in wide spectral range. Nano-size of TiO2 crystals lead to a shift and broadening of the first-order Raman lines through a relaxation of the q = 0 selection rule and effects on to the position, width and asymmetry of a Raman bands. The details of the evolution of the 142.9 cm'1 Raman line shape on the size and distributions of the nanopowders are presented and discussed in frame of confined phonons model. Analysis of Raman spectra shows that structural characteristics of nanopowders may be different even size of the nanopowders is the same. Structural features of the material depend on preparation methods/conditions and can be extracted from Raman spectra of the material. © 2015 Materials Research Society.


Tuschel D.,HORIBA Scientific Inc.
Spectroscopy (Santa Monica) | Year: 2015

External vibrational modes or lowenergy phonons are very sensitive to crystal structure. Here, the author demonstrates the practicality of imaging lowenergy phonons to characterize 2D crystals and provides some cautions to keep in mind.


Tuschel D.,HORIBA Scientific Inc.
Spectroscopy (Santa Monica) | Year: 2012

Polarization/orientation (P/O) micro-Raman spectroscopy can be used to identify vibrational modes, determine crystal structure, distinguish allotropes and polymorphs, differentiate single from polycrystalline materials, and determine orientation of the crystal and degree of disorder, all on a micrometer scale. P/O micro-Raman spectroscopy promises to be an important analytical tool because of its complementarity to micro-X-ray diffraction. Here, we explain the theoretical basis for P/O micro-Raman spectroscopy and provide an example to demonstrate its feasibility.


Chardin H.,ESPCI ParisTech | Mercier K.,HORIBA Scientific Inc. | Frydman C.,HORIBA Scientific Inc. | Vollmer N.,HORIBA Scientific Inc.
Journal of immunological methods | Year: 2014

The biological diagnosis of type I hypersensitivity reactions is based on the quantification of specific IgEs. However, the IgE titer is not always strongly related to the clinical symptoms or predictive of the evolution of the disease. The specificity and affinity of antibodies of other isotypes may contribute to the allergic status of the patients. The aim of the present work was to develop a method that simultaneously detects the complex antibody response to various allergens and measures the avidity of the antibodies directed to each allergen. A chip based on a covalent binding of 3 major milk allergens on a gold-activated surface was developed. The binding of specific antibodies to α-lactalbumin, β-lactoglobulin or caseins was monitored using Surface Plasmon Resonance imaging (SPRi). The sensitivity and specificity of the method were compared to those obtained by ELISA, the reference method. The specificity of the antibodies characterized by SPRi was identical to the one obtained by ELISA. The intensity of the signal was proportional to the quantity of antibodies bound to each allergen. The sensitivity of the SPRi detection was about 8-10 times lower than for ELISA but the SPRi is faster and the analysis of association/dissociation kinetics allowed the determination of the avidity of the antibody response. The present study shows that SPRi allows a multiplex monitoring of the complex antibody response to the major allergens of an allergenic source. This label-free method constitutes a new tool that may be added to IgE detection to improve allergy diagnosis. Copyright © 2014 Elsevier B.V. All rights reserved.


Tuschel D.,HORIBA Scientific Inc.
Spectroscopy (Santa Monica) | Year: 2016

Were it not for the problem of photoluminescence, only one laser excitation wavelength would be necessary to perform Raman spectroscopy. Here, we examine the problem of photoluminescence from the material being analyzed and the substrate on which it is supported. We describe how to select an excitation wavelength that does not generate photoluminescence, reduces the noise level, and yields a Raman spectrum with a superior signal-to-noise ratio. Furthermore, we discuss the phenomenon of resonance Raman spectroscopy and the effect that laser excitation wavelength has on the Raman spectrum.


Yasaei P.,University of Illinois at Chicago | Kumar B.,University of Illinois at Chicago | Foroozan T.,University of Illinois at Chicago | Wang C.,University of Illinois at Chicago | And 5 more authors.
Advanced Materials | Year: 2015

Recent isolation of black phosphorus atomic layers (known as phosphorene) has revealed its great potential for use as an alternative 2D semiconductor in many areas of electronics and optoelectronics. Liquid-phase exfoliation is utilized to produce high-quality black phosphorus nanoflakes with thicknesses down to a monolayer in the form of uniform and stable dispersions, allowing for pace toward practical applications. © 2015 Wiley-VCH Verlag GmbH & Co. KGaA.


Tuschel D.,HORIBA Scientific Inc.
Spectroscopy (Santa Monica) | Year: 2014

In this second installment of a two-part series we present polarized Raman spectra and discuss the association of the symmetry species of the normal vibrational mode and the depolarization ratio of Raman scattering. We discuss those aspects of molecular symmetry and Raman polarization rules that can be applied with normal Raman instrumentation. Materials include liquids, single crystals, and polycrystalline compounds. © 2014 Advanstar Communications Inc.

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