Statistics of Photon Penetration Depth in Diffusive Media

doi:10.1117/3.2624517.ch7

Book: Light Propagation through Biological Tissue and Other Diffusive Media: Theory, Solutions, and Validation, Second Edition

Author(s): Fabrizio Martelli, Tiziano Binzoni, André Liemert, Samuele Del Bianco, Alwin Kienle

Published: 2022

https://doi.org/10.1117/3.2624517.ch7

Author Affiliations +

Abstract

Depth information is implicitly included in any theory of photon migration, and it regards, e.g., the maximum or the average depth probed by the detected light. In biomedical optics applications, the penetration depth can be extremely useful, since it can help to define the part of tissue actually probed by the measurements. Historically, the statistics of photon penetration depth is a topic of great interest. In this chapter, we provide a comprehensive view of the subject, describing the penetration depth of light in random and diffusive media for the TD and CW domains. The main frame of the theory is provided by the RTE, and then explicit analytical formulas are derived for diffusive media by using the DE. Validation of the theory, by means of comparisons with the results of Monte Carlo simulations, will be presented in Ch. 17, which is dedicated to validations. The analytical formulas presented in this chapter are of interest for many research fields such as biomedical optics, advanced microscopy, and disordered photonics.