Attenuation and speckle modulation of laser light in dispersive dye-doped media: Competition of absorption and scattering processes

New insights into the potential factors affecting the emission spectra variability in standoff LIBS

“…[15][16][17] In addition, the presence of particulate matter and aerosols have been proven to alter the propagating waves as a result of different atmospheric phenomena including scattering and absorption. [18][19][20][21] These effects have an impact on the nal outcome of any standoff LIBS analysis as compared to when the technique operates in close-contact mode. 18 While the measurement signicantly affected by these phenomena is the emission intensity, one of the major issues in the standoff operation of LIBS is related to the remarkable uctuations in the shot-to-shot signals; a circumstance that degrades the qualitative and quantitative information provided by the technique.…”

Optical clearing and laser light dynamic scattering near the critical point of fluid in mesoporous materials

“…The Christiansen effect (optical clearing of a disperse system with refractive index matching) can also be identified as the microscopic-level effect manifesting itself at the macroscopic scale. At the microscopic scale this effect is caused by the decreasing scattering efficiency [10] of scattering sites and/or the increasing scattering anisotropy with decreasing refractive index fluctuations in the system [11]. The study of such phenomena opens up new approaches to the elaboration and control of disperse optical materials with specific properties.…”