Optical diagnostics in a flame using Raman and Rayleigh scattering techniques with structured laser illumination

Application of the structured laser illumination to planar optical diagnostics of the flows with nonuniform density

Journal of Physics Conference Series ◽

10.1088/1742-6596/1421/1/012051 ◽

2019 ◽

Vol 1421 ◽

pp. 012051

Author(s):

D Sharaborin ◽

R Tolstoguzov ◽

E Frolova

Keyword(s):

Optical Diagnostics ◽

Laser Illumination

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Optical diagnostics of rough surfaces by inhomogeneously polarized laser illumination

10.1117/12.295697 ◽

1997 ◽

Cited By ~ 4

Author(s):

Oksana I. Barchuck ◽

Alexandr G. Chumakov ◽

Vitalij N. Kurashov

Keyword(s):

Rough Surfaces ◽

Optical Diagnostics ◽

Laser Illumination

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Влияние облучения низкоэнергетическими ионами гелия на спектральный коэффициент отражения монокристаллических молибденовых зеркал

Журнал технической физики ◽

10.21883/jtf.2021.09.51216.37-21 ◽

2021 ◽

Vol 91 (9) ◽

pp. 1369

Author(s):

А.В. Рогов ◽

Ю.В. Капустин ◽

Ю.В. Мартыненко

Keyword(s):

Optical Properties ◽

Surface Layer ◽

Diffuse Scattering ◽

Rayleigh Scattering ◽

Specular Reflection ◽

Optical Diagnostics ◽

Incident Radiation ◽

Skin Layer ◽

Nanoporous Structure ◽

Initial Structure

The results of a comparative study of the effect of irradiation with helium ions on the optical properties of single-crystal molybdenum mirrors with crystallographic orientations <110> and <111> are presented. The irradiation regime corresponds to the conditions in plasma cleaning systems of the entrance mirrors from contamination in optical diagnostics of ITER while helium is using as a working gas. As a result of such irradiation, a change in specular reflection and diffuse scattering of the mirror occurs, which is practically independent of the initial structure of the surface layer of the mirror and the duration of the irradiation process. Authors explain the observed changes in the optical characteristics of the mirror by the formation of nanosized bubbles in the surface skin layer. Rayleigh scattering of incident radiation on these bubles decreases the intensity of specular reflection and increases diffuse scattering. A model of the formation and growth of nanosized bubbles and their effect on optical properties is proposed. The obtained results should be taken into account when analyzing experimental data in optical diagnostics of ITER after removing contaminants using helium, when choosing a working gas for mirror cleaning, and also for the formation of a nanoporous structure in a thin surface layer of metals.

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Confocal Raman mapping

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100132200 ◽

1992 ◽

Vol 50 (2) ◽

pp. 1514-1515

Author(s):

J. Barbillat ◽

M. Delhaye ◽

P. Dhamelincourt

Keyword(s):

Chemical Species ◽

Diffraction Limit ◽

Microscopic Level ◽

Raman Mapping ◽

Complete Spectrum ◽

Laser Illumination ◽

Ccd Detector ◽

Raman Microprobe ◽

Photodiode Array ◽

Raman Image

Raman mapping, with a spatial resolution close to the diffraction limit, can help to reveal the distribution of chemical species at the surface of an heterogeneous sample.As early as 1975,three methods of sample laser illumination and detector configuration have been proposed to perform Raman mapping at the microscopic level (Fig. 1),:- Point illumination:The basic design of the instrument is a classical Raman microprobe equipped with a PM tube or either a linear photodiode array or a two-dimensional CCD detector. A laser beam is focused on a very small area ,close to the diffraction limit.In order to explore the whole surface of the sample,the specimen is moved sequentially beneath the microscope by means of a motorized XY stage. For each point analyzed, a complete spectrum is obtained from which spectral information of interest is extracted for Raman image reconstruction.- Line illuminationA narrow laser line is focused onto the sample either by a cylindrical lens or by a scanning device and is optically conjugated with the entrance slit of the stigmatic spectrograph.

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