Substrate Effects On Two-dimensional Laser Beam Backscattering
Abstract
Experimental measurements of backscattering from media with optical depths ranging from thin to thick and composed of anisotropic scattering particles exposed to a laser beam are presented. The laser beam is incident normal to the first surface of a scattering medium whose substrate is a diffuse reflector. Measurements are made for two substrates (white - nearly 100% reflecting, and black - nearly 100% absorbing) to study the effect of substrate reflection on backscatter. Latex particles of uniform size (diameter = 0.18 μm) are used as scattering centers in a water solution to create the scattering medium. Results are presented for backscattered radiation in the normal direction as a function of optical radius from the laser beam, optical thickness of the scattering medium, and the character of the substrate for albedos near one. It is shown that the character of the substrate can be important for optical depths up to 20. The white reflecting substrate always produces greater backscattered radiation than the black absorbing substrate when effects of the substrate are detectable. A correlation is developed that predicts the onset of substrate effects on the backscattered radiation as a function of optical radius and optical depth.
Recommended Citation
H. F. Nelson and D. C. Look, "Substrate Effects On Two-dimensional Laser Beam Backscattering," Journal of Thermophysics and Heat Transfer, vol. 2, no. 3, pp. 203 - 208, American Institute of Aeronautics and Astronautics, Jan 1988.
The definitive version is available at https://doi.org/10.2514/3.89
Department(s)
Mechanical and Aerospace Engineering
International Standard Serial Number (ISSN)
1533-6808; 0887-8722
Document Type
Article - Conference proceedings
Document Version
Citation
File Type
text
Language(s)
English
Rights
© 2023 American Institute of Aeronautics and Astronautics, All rights reserved.
Publication Date
01 Jan 1988
Comments
National Science Foundation, Grant CBT 85-01099