A remote Raman system has been developed utilizing a 532nm pulsed laser and gated intensified charged couple device (ICCD) detector in the oblique geometry. When the system is set for 50m sample distance it is capable of measuring Raman spectra of minerals located at distances in the range of 10-65m from the telescope. Both daytime and nighttime operations are feasible and the spectra of minera...

Raman spectroscopy is a powerful non-destructive technique for qualitatively and quantitatively characterizing materials. However, noise often obscures interesting Raman peaks due to the inherently weak Raman signal, especially in biological samples. In this study, we develop a method based on spectral reconstruction to recover Raman spectra with low signal-to-noise ratio (SNR). The synthesis o...

The resonance Raman spectra of (IAuI)~-anions in the organic superconductor Y?-(BEDTTTF)2IAUI as well as in the electrolyte salt n-Bu4AuI2 are investigated. In contrast to /?-(BEDT-TTF)2I3 in the crystals of /?-(BEDT-TTF)2IAuI at low temperature only one Raman line at 120 cm" 1 corresponding to the symmetrical stretching mode of the (IAuI)"-anion is observed. No distinct change in the Raman spe...

The aim of this study was to evaluate the suitability of Raman spectroscopy as a Process Analytical Technology (PAT) tool for the in-line determination of the active pharmaceutical ingredient (API) concentration and the polymer-drug solid state during a pharmaceutical hot-melt extrusion process. For in-line API quantification, different metoprolol tartrate (MPT)--Eudragit® RL PO mixtures, conta...

Raman microspectroscopy is a label-free and nondestructive technique to measure the intrinsic chemical profile of single cells. The naturally weak Raman signals hampered the application of Raman spectroscopy for high-throughput measurements. Nearly all photosynthetic microorganisms contain carotenoids that are active molecules for resonance Raman at a 532 nm excitation wavelength. Hence, the ac...

The intensity and selection rules of Raman spectra change as a metal surface approaches the sample. We study the distance dependence of the new Raman modes with a near-field scanning optical microscope ~NSOM!. The metal-coated NSOM probe provides localized illumination of a metal surface with good distance control. Spectra are measured as the probe approaches the surface, and the changes elucid...

The contamination of the Raman scattering signal with luminescence is a well-known problem when dealing with biological media excited by visible light. The viability of the shifted-excitation Raman difference spectroscopy (SERDS) technique for luminescence suppression on Raman spectra of biological samples was studied in this work. A tunable Lithrow-configuration diode laser (λ = 785 and 830 nm...

We present a novel parallel Raman microspectroscopy scheme for simultaneously collecting Raman spectra from multiple points. This scheme is realized by projectinga multiple-point laser illumination pattern using a spatial light modulator (SLM) and wide-field Raman imaging collection. We demonstrate the performance of this scheme using uniform samples, trapped polymer microparticles and fixed po...

PURPOSE The aim of this study was to use Raman spectra of tears to differentiate between infectious and noninfectious ulcerative keratitis. METHODS Raman microspectroscopy was applied using the drop-coating deposition method on Ti/Au-coated glass slides to obtain sample spectra from different human tear groups, including tears from healthy subjects and from patients with infectious and noninf...

Laser tweezers Raman spectroscopy (LTRS) was used to acquire the Raman spectra of leukemic T lymphocytes exposed to the chemotherapy drug doxorubicin at different time points over 72 hours. Changes observed in the Raman spectra were dependent on drug exposure time and concentration. The sequence of spectral changes includes an intensity increase in lipid Raman peaks, followed by an intensity in...