BACKGROUND A profile across 8 layers from a fossil travertine terrace from a low temperature geothermal spring located in Svalbard, Norway has been studied using both Raman spectroscopy and SEM (Scanning Electron Microscopy) techniques to identify minerals and organic life signals. RESULTS Calcite, anatase, quartz, haematite, magnetite and graphite as well as scytonemin, three different carot...

Spontaneous cascaded Raman amplification is demonstrated as a practical and efficient means of power transfer from telecommunications wavelengths to mid-IR wavelength bands through use of conventional silica fibers and amplifiers. We show that silica fibers possessing normal dispersion over all near-IR and mid-IR wavelengths can facilitate 37% and 16% efficient Raman power conversion from 1.53 ...

The microstructural changes associated with the formation of lithium tantalate waveguides after high repetition rate ultrafast laser inscription has been investigated by confocal micro-Raman experiments. While the laser beam focal volume is characterized by significant lattice damage, no reduction of Raman mode strength has been observed at the guiding region, suggesting the preservation of the...

We show that coherent anti-Stokes Raman lineshapes do not follow known spectral profiles if the time asymmetry of realistic laser pulses is taken into account. Examples are given for nanosecond and picosecond laser pulses commonly employed in frequency-resolved coherent anti-Stokes Raman scattering. More remarkably, the analysis suggests an effect of line narrowing in comparison to the customar...

We demonstrate the direct generation of a first-order LG(01) Laguerre Gaussian (vortex) mode operating at the first-Stokes wavelength of a diode end-pumped, Nd:GdVO(4) self-Raman laser. To the best of our knowledge, this is the first report of intracavity stimulated Raman scattering (SRS) being used as a method for frequency conversion of a vortex laser beam and it is effective in enabling the ...

A fully integrated UV Townsend Effect Plasma Spectroscopy (TEPS)-Raman system has been constructed for use of standoff detection of energetic materials. A single 266nm Q-Switched Nd:YAG Laser was used for Raman excitation and TEPS plasma ignition. A nearly simultaneous 10.6um CO2 laser is employed for the signal enhancement in the TEPS measurements. Chemometric techniques are presented for anal...

Laser Raman spectroscopy has been used detect structural changes in troponin C induced by Ca2+ binding. Addition of Ca2+ - Mg2+ sites produces perturbations in the amide III region of the spectrum indicative of increased alpha-helical content, and in regions of the spectrum corresponding to carboxylate, thiol, and phenol side chains. However, Ca2+ binding to the low affinity Ca2+ - specific sit...

In Raman spectroscopic measurements of single cells (human lymphocytes) and chromosomes, using a newly developed confocal Raman microspectrometer and a laser excitation wavelength of 514.5 nm, degradat ion of the biological objects was observed. In the experiments high power microscope objectives were used, focusing the laser beam into a spot 0.5 pm in diameter. At the position of the laser foc...

Nonlinear Raman microspectroscopy based on a broadband coherent anti-Stokes Raman scattering is an emerging technique for noninvasive, chemically specific, microscopic analysis of tissues and large population of cells and particles. The sensitivity of this imaging is a critical aspect of a number of the proposed biomedical application. It is shown that the incident laser power is the major para...

Introduction: We present recent developments in instrumentation for in situ planetary time-resolved Raman spectroscopy, leading to improved performance and identification of both minerals and organics. The Time-Resolved Raman Instrument shown in Figure 1 builds on the widely used 532 nm (green) laser Raman technique, but uses time resolution to detect Raman spectral signatures while eliminating...