Spectroscopic requirements for Raman instrumentation on a planetary lander: potential for the remote detection of biosignatures on Mars

2004 ◽  
Vol 3 (2) ◽  
pp. 165-174 ◽  
Author(s):  
S.E. Jorge Villar ◽  
H.G.M. Edwards
Keyword(s):  
Raman Spectroscopy ◽  
Raman Spectra ◽  
Spectral Resolution ◽  
Detection Sensitivity ◽  
Remote Detection ◽  
Spectral Identification ◽  
Scan Time ◽  
Time Parameters ◽  
Raman Spectral ◽  
Non Destructive

The special characteristics of Raman spectroscopy (relative insensitivity to water, non-destructive detection, sensitivity to bio- and geosignatures, molecular structural composition information, etc.) together with the development of miniaturized Raman spectrometers make the consideration of this technique for future robotic landers on planetary surfaces, particularly Mars, a very interesting option. The development of light and rugged Raman spectrometers limits the possible scope of the instrumentation which has particular importance in the recognition of biomolecular and mineral signatures. In this work, we evaluate the spectral resolution and scan time parameters and the effect that they have on the Raman spectra of extremophilic biomolecules, together with the wavenumber ranges which are critical for the detection of life signals. This is of vital relevance for the design of miniaturized Raman spectrometer systems. From our results, we conclude that for extraterrestrial biological signatures unambiguous Raman spectral identification provided with a minimum of 16 cm−1 spectral resolution is required for the most significant biosignature wavenumber range in the 1700–700 cm−1 region.

Raman Spectral Characterization of Pure and Doped Fused Silica Optical Fibers

1975 ◽  
Vol 29 (4) ◽  
pp. 337-344 ◽  
Author(s):  
G. E. Walrafen ◽  
J. Stone
Keyword(s):  
Raman Spectroscopy ◽  
Raman Spectra ◽  
Optical Fibers ◽  
Fused Silica ◽  
Laser Raman ◽  
Laser Raman Spectra ◽  
Raman Spectral ◽  
Oh Content ◽  
Absorption Measurements

The utility of Raman spectroscopy as a means of characterizing the properties of pure and doped fused silica has been investigated. Laser-Raman spectra were obtained by forward scattering from solid optical fibers ∼35 to 85 m in length using 514.5 nm excitation with an “image slicer” and a Cary model 81 instrument. Clad and unclad fibers of fused silica and doped fibers having SiO2-GeO2 and SiO2-GeO2-B2O3 cores were examined. Raman spectra were also obtained from bulk samples of glasses, including pure GeO2, pure B2O3, and various compositions of SiO2-GeO2, SiO2-B2O3, and SiO2-GeO2-B2O3. The addition of dopants to fused silica was found to alter the Raman spectrum both by the appearance of new bands, roughly proportional to dopant concentration and not common either to the fused silica or to the dopant alone, and by the marked alteration of other Raman bands, which is indicative of changes in the local intermolecular order. Thus, addition of GeO2 produces new Raman bands at ∼675 and ∼1000 cm−1; and of B2O3, new bands at ∼940 and ∼1350 cm−1. Addition of GeO2 and/or B2O3 weakens the relatively sharp Raman lines near 485 and 600 cm−1 (and a similar but small effect was also noted with increasing OH content). GeO2 and B2O3 together also produce observable narrowing of the broad intense 440 cm−1 Raman contour. These spectral effects are interpreted, respectively, in terms of a decrease in the concentrations of [Formula: see text] and [Formula: see text] defects produced by dopant addition and of a concomitant reordering of the silica structure. Raman spectroscopy thus appears to be a useful optical technique for elucidating the properties of dopants that have been especially chosen for good optical transmission and hence are not easily detectable by absorption measurements.

scholarly journals RDX remote Raman detection on NATO SET-237 samples

2021 ◽  
Vol 136 (4) ◽  
Author(s):  
Emanuela C. A. Gallo ◽  
Luca M. L. Cantu ◽  
Frank Duschek
Keyword(s):  
Raman Spectroscopy ◽  
Excitation Energy ◽  
Raman Spectra ◽  
Ccd Camera ◽  
Surface Concentration ◽  
Remote Detection ◽  
Excitation Wavelength ◽  
Standard Samples ◽  
Minimum Requirements

AbstractUltraviolet Raman spectroscopy measurements have been taken at DLR in Lampoldshausen to detect NATO SET-237 standard samples of RDX. The main goal was to quantify the minimum requirements for an unambiguous identification in remote detection (60 cm distance) with a commercial Czerny–Turner spectrometer coupled with a CCD camera. Well-defined distribution of explosives on surfaces was tested as standardized samples. Therefore, Raman spectra of RDX have been acquired for different sample concentrations (50, 250 and 1000 μg/cm2, respectively) and under several laser energies (1.5, 3.0 and 5.0 mJ/pulse, respectively) at 355 nm excitation wavelength. The lowest possible reproducible surface concentration (50 µg/cm2) was detected with excitation energy of 3 mJ/pulse in the described configuration.

Expressing Raman Spectral Details Through Raman Parameter Information Diagram (RAPID)

2018 ◽  
Author(s):  
Rajesh Kumar
Keyword(s):  
Raman Spectroscopy ◽  
Raman Spectrum ◽  
Raman Spectra ◽  
Blue Shift ◽  
Spectral Features ◽  
Good Tool ◽  
Spectral Parameters ◽  
Raman Spectral ◽  
Pictorial Form

A handy diagram with name RAPID (Raman parameter information diagram) is proposed here which can be<br>used for listing spectral parameters associated with a Raman spectrum. It is demonstrated how by drawing<br>simple shapes like lines, triangles etc, it becomes easy to express various nding in a Raman spectrum like<br>red- (or blue-) shift, asymmetry, broadening, antiresonance etc. It will also be explained how by following<br>certain protocols, conveying Raman spectral features becomes easier unambiguously in a pictorial form,<br>proposed to be called as \RAPID" diagram. The proposed diagram will certainly prove to be a good tool in<br>the eld of Raman spectroscopy. It will be noticed that, though it is proposed for Raman spectra, RAPID<br>diagram can be used for representing features of any spectra.

Microchip Lasers as a Compact Excitation Source for Raman Spectroscopy

2000 ◽  
Vol 54 (5) ◽  
pp. 739-741 ◽  
Author(s):  
Alfons Schulte ◽  
Chris Fredricksen ◽  
Scott Buchter ◽  
Greg Mizell
Keyword(s):  
Thin Films ◽  
Raman Spectroscopy ◽  
Solid State ◽  
Raman Spectra ◽  
Solid State Laser ◽  
Microchip Laser ◽  
Laser Source ◽  
Spectral Measurements ◽  
Microchip Lasers ◽  
Raman Spectral

The application of a new microchip laser source for Raman spectral measurements is demonstrated. The performance of the device is evaluated and illustrated by Raman spectra of diamond thin films and a solid-state laser host material.

Expressing Raman Spectral Details Through Raman Parameter Information Diagram (RAPID)

2018 ◽  
Author(s):  
Rajesh Kumar
Keyword(s):  
Raman Spectroscopy ◽  
Raman Spectrum ◽  
Raman Spectra ◽  
Blue Shift ◽  
Spectral Features ◽  
Good Tool ◽  
Spectral Parameters ◽  
Raman Spectral ◽  
Pictorial Form

A handy diagram with name RAPID (Raman parameter information diagram) is proposed here which can be<br>used for listing spectral parameters associated with a Raman spectrum. It is demonstrated how by drawing<br>simple shapes like lines, triangles etc, it becomes easy to express various nding in a Raman spectrum like<br>red- (or blue-) shift, asymmetry, broadening, antiresonance etc. It will also be explained how by following<br>certain protocols, conveying Raman spectral features becomes easier unambiguously in a pictorial form,<br>proposed to be called as \RAPID" diagram. The proposed diagram will certainly prove to be a good tool in<br>the eld of Raman spectroscopy. It will be noticed that, though it is proposed for Raman spectra, RAPID<br>diagram can be used for representing features of any spectra.

Differentiation of Edible Oils by Type Using Raman Spectroscopy and Pattern Recognition Methods

2020 ◽  
Vol 74 (6) ◽  
pp. 645-654 ◽  
Author(s):  
Francis Kwofie ◽  
Barry K. Lavine ◽  
Joshua Ottaway ◽  
Karl Booksh
Keyword(s):  
Fatty Acids ◽  
Pattern Recognition ◽  
Raman Spectroscopy ◽  
Raman Spectra ◽  
Edible Oils ◽  
Monounsaturated Fatty Acids ◽  
Degree Of Saturation ◽  
Pattern Recognition Methods ◽  
Raman Spectral Data ◽  
Raman Spectral

The application of Raman spectroscopy and pattern recognition methods to the problem of discriminating edible oils by type was investigated. Two-hundred and eighty-six Raman spectra obtained from 53 samples spanning 15 varieties of edible oils were collected for 90 s at 2 cm–1 resolution. Employing a Whittaker filter, all Raman spectra were baseline corrected after removing the high-intensity fluorescent background in each spectrum. The Raman spectral data were then examined using the three major types of pattern recognition methodology: mapping and display, discriminant development and clustering. The 15 varieties of edible oils could be partitioned into five distinct groups based on their degree of saturation and the ratio of polyunsaturated fatty acids to monounsaturated fatty acids. Edible oils assigned to one group could be readily differentiated from those assigned to other groups, whereas Raman spectra within the same group more closely resembled each other and therefore would be more difficult to classify by type.

scholarly journals Raman spectroscopy in thrust-stacked carbonates: an investigation of spectral parameters with implications for temperature calculations in strained samples

2021 ◽  
Author(s):  
Lauren Kedar ◽  
Clare E. Bond ◽  
David Muirhead
Keyword(s):  
Raman Spectroscopy ◽  
Raman Spectra ◽  
Multiple Scales ◽  
Raman Band ◽  
Frictional Heating ◽  
Shear Zones ◽  
Spectral Parameters ◽  
Thrust Belts ◽  
Carbonate Sequence ◽  
Raman Spectral

Abstract. Raman spectroscopy is commonly used to estimate peak temperatures in rocks containing organic carbon. In geological settings such as fold-thrust belts, temperature constraints are particularly important as complex burial and exhumation histories cannot easily be modelled. Many authors have developed equations to determine peak tempertaures from Raman spectral parameters, most recently to temperatures as low as 75 °C. However, recent work has shown that Raman spectra can be affected by strain as well as temperature. Fold-thrust systems are often highly deformed on multiple scales, with deformation characterised by faults and shear zones, and therefore temperatures derived from Raman spectra in these settings may be erroneous. In this study, we investigate how the four most common Raman spectral parameters and ratios change through a thrust-stacked carbonate sequence. By comparing samples from relatively low-strain localities to those on thrust planes and in shear zones, we show maximum differences of 0.16 for I[d]/I[g] and 0.11 for R2, while FWHM[d] and Raman Band Separation show no significant change between low and high strained samples. Plausible frictional heating temperatures of faulted samples suggest that the observed changes in Raman spectra are not the result of frictional heating. We apply three equations used to derive the peak temperatures from Raman spectra to our data to investigate the implications on predicted temperatures between strained and unstrained samples. All three equations produce different temperature gradients with depth in unstrained samples. We observe that individual equations exhibit apparently varying sensitivities to strain, but calculated temperatures can be up to 140 °C different for adjacent strained and unstrained samples using the same temperature equation. These results have implications for how temperatures are determined in strained rock samples from Raman spectra.

A Raman spectral study of the equilibria of zinc bromide complexes in DMSO solutions

1989 ◽  
Vol 67 (11) ◽  
pp. 2030-2036 ◽  
Author(s):  
Jeff Van Heumen ◽  
Toru Ozeki ◽  
Donald E. Irish
Keyword(s):  
Raman Spectroscopy ◽  
Factor Analysis ◽  
Raman Spectra ◽  
Spectral Study ◽  
Formation Constant ◽  
Dmso Solution ◽  
Zinc Bromide ◽  
Raman Spectral ◽  
Stepwise Formation

Using Raman spectroscopy, the stepwise formation of zinc bromide complexes in dimethylsulfoxide (DMSO) solution has been investigated. The presence of four different zinc bromide complexes is suggested and their Raman spectra have been extracted. The formation constant of each reaction has been estimated by the application of factor analysis to the spectra. The usual methods of factor analysis have been extended by the introduction of constraints imposed by the equilibria. Keywords: zinc bromide complexes, solvation in DMSO, Raman spectroscopy, factor analysis.

scholarly journals Prediction of Trained Panel Sensory Scores for Beef with Non-Invasive Raman Spectroscopy

Chemosensors ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 6
Author(s):  
Jamie Cafferky ◽  
Raquel Cama-Moncunill ◽  
Torres Sweeney ◽  
Paul Allen ◽  
Andrew Cromie ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Raman Spectra ◽  
Sensory Quality ◽  
Predictive Accuracy ◽  
Sensory Panel ◽  
Non Invasive ◽  
Trained Panel ◽  
After Effect ◽  
Non Destructive

The objective of this study was to investigate Raman spectroscopy as a tool for the prediction of sensory quality in beef. Raman spectra were collected from M. longissimus thoracis et lumborum (LTL) muscle on a thawed steak frozen 48 h post-mortem. Another steak was removed from the muscle and aged for 14 days before being assessed for 12 sensory traits by a trained panel. The most accurate coefficients of determination of cross validation (R2CV) calibrated within the current study were for the trained sensory panel textural scores; particularly tenderness (0.46), chewiness (0.43), stringiness (0.35) and difficulty to swallow (0.33), with practical predictions also achieved for metallic flavour (0.52), fatty after-effect (0.44) and juiciness (0.36). In general, the application of mathematical spectral pre-treatments to Raman spectra improved the predictive accuracy of chemometric models developed. This study provides calibrations for valuable quality traits derived from a trained sensory panel in a non-destructive manner, using Raman spectra collected at a time-point compatible with meat management systems.

Submicron Simultaneous IR and Raman Spectroscopy (IR+Raman): Breakthrough Developments in Optical Photothermal IR (O-PTIR) Combined for Enhanced Failure Analysis

2019 ◽  
Author(s):  
Jay Anderson ◽  
Mustafa Kansiz ◽  
Michael Lo ◽  
Curtis Marcott
Keyword(s):  
Raman Spectroscopy ◽  
Failure Analysis ◽  
Data Quality ◽  
Raman Spectra ◽  
Spatial Resolution ◽  
Far Field ◽  
Field Mode ◽  
Microscopic Scale ◽  
Analytical Tools ◽  
Ir And Raman

Abstract Failure analysis of organics at the microscopic scale is an increasingly important requirement, with traditional analytical tools such as FTIR and Raman microscopy, having significant limitations in either spatial resolution or data quality. We introduce here a new method of obtaining Infrared microspectroscopic information, at the submicron level in reflection (far-field) mode, called Optical-Photothermal Infrared (O-PTIR) spectroscopy, that can also generate simultaneous Raman spectra, from the same spot, at the same time and with the same spatial resolution. This novel combination of these two correlative techniques can be considered to be complimentary and confirmatory, in which the IR confirms the Raman result and vice-versa, to yield more accurate and therefore more confident organic unknowns analysis.

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