Spectroscopy White Papers and Case Studies

  1. Low Frequency Raman Spectroscopy

    The B&W Tek BAC102 series E-grade probe is able to access frequency modes as low as 65cm-1. Access to lower frequencies provides key information for applications involving protein characterization, polymorph detection and identification, and material phase and structure determination. This article discusses how the low frequency E-grade probe can be a valuable asset in many applications including studying semiconductor lattices, carbon nanotubes, solar cells, and many kinds of minerals, pigments, and gemstones.

  2. Cherenkov Emission Imaging And Spectroscopy Utilizing Isotopes And A Linear Accelerator

    There are linear accelerators (LINACs) employed in radiation oncology that produce radiation in pulsed microseconds-long bursts, generated by the accelerator waveguide. By taking advantage of a LINAC’s inherent pulsed operation, time-gated detection of Cherenkov radiation is possible, significantly improving the ratio of signal to ambient light. Recently, a research group at Dartmouth College and Dartmouth-Hitchcock Medical Center in New Hampshire led by Dr. Brian Pogue has investigated fluorescence and absorption spectroscopy methods using pulsed LINAC-induced CES2, under ambient room lighting conditions. An overview of some of their work is provided in this application note.

  3. Application Of The Shifted Excitation Raman Difference Spectroscopy (SERDS) To The Analysis Of Trace Amounts Of Methanol In Red Wines

    Shifted Excitation Raman Difference Spectroscopy (SERDS) has proven an effective method for performing Raman analysis of fluorescent samples. This technique allows achieving excellent signal to noise performance with shorter excitation wavelengths, thus taking full advantage of the superior signal strength afforded by shorter excitation wavelengths and the superior performance, also combined with lower cost, delivered by silicon CCDs.

  4. Analysis Of Fluorescent Substances And Binary Mixtures Through Shifted Excitation Raman Difference Spectroscopy

    In this article, shifted excitation Raman difference spectroscopy (SERDS) implemented with two wavelength-stabilized laser diodes with fixed wavelength separation is discussed as an effective method for dealing with the effects of fluorescence in Raman spectroscopic analysis.

  5. Eliminating The Trade-Off Between Resolution And Throughput In Raman Spectroscopy

    Raman spectroscopy is gaining intense interest as an analytical tool due to the strong specificity of the Raman signature of many materials. However, the Raman signal is often very weak and traditional slit spectrometers typically have poor optical throughput — mostly due to the slit itself. In this application note, we introduce the Apex spectrometer, the first product in the Elite Series of high-performance spectrometers, light sources and sampling accessories.

  6. Measuring The Opacity Of Plastic Tubing With VIS-NIR Transmission Spectroscopy

    Plastic tubing is available in a variety of opacities ranging from clear to translucent. The transparency of plastic tubing is varied for a number of reasons including providing contrast for visual monitoring of fluid flow, decreasing exposure to ambient light and making the tubing more distinct for machine vision technology. In this application note, VIS-NIR transmission spectroscopy is used to assess the amount of frosting applied to plastic tubing to determine if the tubing meets the required opacity level.

  7. Laser Induced Breakdown Spectroscopy (LIBS): Application Note

    Using a pulsed laser to create a surface ablation on a sample and then spectroscopically analyzing its elemental and molecular composition is known as Laser Induced Breakdown Spectroscopy (LIBS). This form of spectroscopy has been greatly helped with the advent of fiber optic spectrometers, as their flexibility has enabled the measurement of LIBS plasma in harsh or challenging environments. This application discussed the advantages of LIBS, and also explores different instruments that can be used in such an application.

  8. Dispersive Imaging Spectrograph Designs For Raman Spectroscopy And Their Impact On Spectral And Spatial Resolution

    Raman spectroscopy is experiencing a rapid increase in commercial and military application integration. There has been a large amount of commercial discussion regarding relatively low cost, low resolution single point (single fiber) spectrometers for handheld transportable applications, although only limited advancement of higher performance designs. By Jay Zakrzewski and Kevin Didona, Headwall Photonics, Inc.

  9. Modular Raman Spectroscopy for Chemical Alcohol Discrimination

    Raman Spectroscopy provides convenient and rapid analysis for chemical sample identification, including alcohol and alcohol isomers. Its non-invasive measurement capabilities provide reliable and non-destructive testing in aqueous solutions, powders, gels, tablets, and surfaces. Additionally, there is no interference from water, and little to no sample preparation is required. This application note demonstrates how Ocean Optics modular Raman components differentiate between 10 different alcohol samples with similar molecular formulas.

  10. Diffuse Spectroscopy For Inhomogeneous Metal Nanoparticle Assays

    We describe a compact computational spectroscopy platform optimized for molecular recognition using metal nanoparticle assays. The objective is motivated by the urgent need for low-cost, portable and high-throughput sensors for point-of-care (POC) clinical diagnostics. Nanoparticle based sensing has been successfully demonstrated for diagnosis and monitoring of infectious diseases, drug discovery, proteomics, and biological agent detection. Molecular binding on the nanoparticle surface is transuded into an optical signal by modification of the nanoparticle extinction spectrum (via a shift in Localized Surface Plasmon Resonance) or by modification of the molecular scattering spectrum (via Surface Enhanced Raman Scattering). By Prasant Potuluri, Michael E. Sullivan, Yanqia Wang, David J. Brady, Centice