TOP
TOP
TPDSci Logo
What is TPDSci | Contact Support TPDSci Project

 Topics in Particle and Dispersion Science

  Home | Survey | Topics | Index | References | Dictionary | Contribute | Gallery | Community | Search

Attenuation of light: Effect of absorption Parent topic

Transmission of light through absorbing medium
 
Fig. 1. Schematic illustration of the effect of light absorption on transmission of light through a medium. The white arrows symbolically represent the photon paths. A path should not be interpreted as a localized photon trajectory because photons of a plane wave have infinite extent in a direction orthogonal to the propagation direction. Fly the mouse over a path link in the text below to show the relevant path alone. The source (S) is unidirectional and the detector (D) is sensitive at least to radiation incident from S.

Interaction with an absorption center (electron, atom, molecule, particle) i.e. an absorption event, terminates a photon path (for example, path 1). Only those photons reach the detector that do not experience absorption events (for example, path 2). The probability distribution of path lengths, L, between the light source and an absorption event is p(L) = exp(-aL), where a is the absorption coefficient (for example, Mobley CD 1994, Ch. 6). Energy removed from the beam by an absorption event may be released back to the medium through non-radiative processes. See also effects of single scattering and multiple scattering on transmission of light by a medium.

CITATION:
Swanson N. L., Jonasz M. 2007. Attenuation of light: Contributing processes - effect of absorption (www.tpdsci.com/Tpc/AtnCtbFigAbs.php). In: Top. Part. Disp. Sci. (www.tpdsci.com).
HISTORY:
Published: 21-Nov-2007
Modified: 04-Jun-2010
Peer-reviewed: 22-Dec-2007
Journals | Journals search | Contributing | | Menu
Copyright 2005-2012 TPDSci Inc. All rights reserved. | Terms of use