Absorption Corrections and Concentration Optimization for Absorbing Samples in Resonance Raman Spectroscopy

1974 ◽  
Vol 28 (4) ◽  
pp. 324-327 ◽  
Author(s):  
Thomas C. Strekas ◽  
David H. Adams ◽  
Andrew Packer ◽  
Thomas G. Spiro
Keyword(s):  
Raman Spectroscopy ◽  
Path Length ◽  
Resonance Raman Spectroscopy ◽  
Resonance Raman ◽  
Optimum Concentration ◽  
The Self ◽  
Light Path ◽  
Intensity Measurements ◽  
Concentration Curves ◽  
Transverse Scattering

For Raman scattering studies of absorbing samples, e.g., in resonance Raman spectroscopy, it is frequently important to optimize the concentration and to correct for self-absorption effects on the observed intensities. These question are explored for 90° “transverse” scattering in a 0.1-cm capillary through intensity measurements of resonance Raman bands of ferro-cytochrome c and tris(1,10-phenanthroline) iron (II). It is found that a simple log intensity vs concentration plot provides the extrapolation needed to eliminate self-absorption effects. The optimum concentration is found to correspond to an absorbance per 1 cm of path length of 13 (average of values for the incident and scattered wavelengths) and is independent of absorptivity and of refractive index of the medium. The data are adequately reproduced by a point-scattering model, although different values of the effective light path through the sample are required to fit the self-absorption and intensity vs concentration curves.

scholarly journals The Influence of LightPath Length on the Color of Flame-Fusion Synthetic Ruby

2021 ◽  
Author(s):  
Bin Yuan ◽  
Ying Guo ◽  
Ziyuan Liu
Keyword(s):  
Visible Light ◽  
Light Source ◽  
Path Length ◽  
Color Difference ◽  
Light Path ◽  
Light Spectrum ◽  
Strong Absorption Band ◽  
Vis Spectroscopy ◽  
Path Lengths ◽  
New Perspective

Abstract Colorimetric studies of different light path lengths from a new perspective of UV-Vis spectroscopy. The corrected ultraviolet-visible light spectrum was used to calculate the color of flame-fusion synthetic ruby, and the influence of light path length and standard light source on the color of flame-fusion synthetic ruby was studied. The results show that the L*, C*, h° under the A light source are higher than those under the D65 light source. In the ultraviolet-visible light spectrum, the strong absorption band of Cr3+ at 545nm is the main cause of the color of the ruby. As the length of the light path increases, the absorption peak area at 545nm also increases, the lightness L* decreases, and the hue angle h° increases. The chroma C* first increases as the length of the light path increases, and then begins to decrease under the influence of the continuous decrease in lightness. The color difference ΔE*ab reaches the maximum when the light path length is around 10mm, and the standard light source has the greatest influence on the color difference ΔE*ab. As the length of the light path continues to increase, the influence of the standard light source on the color difference\(\)ΔE*ab decreases.

scholarly journals A Time-symmetric Hubble-like Law: Light Rays Grazing Randomly Moving Galaxies Show Distance-Proportional Redshift

2003 ◽  
Vol 58 (12) ◽  
pp. 807-809 ◽  
Author(s):  
O. E. Rössler ◽  
D. Fröhlich ◽  
N. Kleiner
Keyword(s):  
Time Reversal ◽  
Quantitative Estimate ◽  
Path Length ◽  
Real Space ◽  
Dissipative Structures ◽  
Light Path ◽  
New Class ◽  
Bias Factor ◽  
Light Rays ◽  
Dynamic Path

A new class of dissipative structures is proposed that live in real space rather than phase space. A light ray passing through a soup of randomly moving gravitating masses is a case in point. It suffers a “dynamic path elongation” since the random pushes and pulls have a greater probability of increasing than decreasing its path length. Time reversal then re-shrinks the path in question in a conspirational manner, while a close-by nonselected path gets expanded. This is a new statistical-mechanics phenomenon. The latter at the same time qualitatively reproduces the well-known Hubble phenomenon of distance-proportional light-path expansion in the cosmos. A preliminary quantitative estimate, based on the Birkinshaw equation with an assumed bias factor of three, is also presented.

scholarly journals The Two-Mirror Telescope (2MT)

1984 ◽  
Vol 79 ◽  
pp. 347-365
Author(s):  
Richard G. Bingham
Keyword(s):  
Optical Spectroscopy ◽  
Path Length ◽  
Infrared Imaging ◽  
Angular Resolution ◽  
Vertical Axis ◽  
Light Path ◽  
Large Telescope ◽  
Future Extension ◽  
Mirror Telescope ◽  
Mechanical Arrangement

SUMMARYTwo eight-metre mirrors on an alt-azimuth mount are considered as a Future Large Telescope. The combined collecting area is ten times that of a four-metre class telescope, and the main modes of use are for optical spectroscopy and infrared imaging. In one square arc second, at 10µm wavelength, the telescope with adaptive auxiliary optics will yield 30 to 100 fully resolved image elements (not speckles). The mechanical arrangement proposed to give path length stability is to link the two tube centre sections along a horizontal axis and to use a total of four altitude bearings. A combined focus is necessary for the highest angular resolution, but other work such as spectroscopy can be carried out either at a combined focus or using separate instrumentation for the two eight-metre apertures. Twin prime and Cassegrain foci and horizontal Nasmyth platforms are intended for such pairs of spectrographs and other instruments, depending on their weight and field requirements. A pair of prime focus spectrographs with f/0.8 cameras is one appropriate system. (The horizontal Nasmyth platforms to accommodate larger spectrographs are a feature of this telescope which is not feasible in other MMT-type configurations). Another significant capability is that for a coud6-type light path from either aperture to the vertical axis. This can be achieved with four reflections (including the primary) for some applications. In addition to the conventional uses of the coudg light path, there is the possibility of using it to produce interferometric links to other telescopes. These links may be important as a future extension of the instrument.

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