Chapter 5
Study of the Optical Characteristics
of a Biotissue with Large-Scale
Inhomogeneities
Abstract We construct the electrodynamic model which makes it possible to vary
the electrophysical parameters of a biological structure in calculations with allowance
for roughness (real and imaginary parts of the refractive index of the epidermis, the
upper layer of the derma, and blood) and to establish the dependences between these
parameters and the biological properties of blood under the action of laser radiation
in vivo.
5.1 Introduction
It should be noted that the study of propagation of light in randomly inhomogeneous
media is mainly based on the classical methods of the transport theory. However,
the application of the radiation transport theory is not always effective in the study
of propagation of light in randomly inhomogeneous media (in particular, biological
media). It is well known that most biological surfaces are not planar but are rather
loose randomly rough media, in which the size of roughness are larger than the
wavelength of radiation illuminating them. The roughness of the surfaces affects the
characteristics of propagation and scattering of waves. A wave incident on a rough
surface is not only reflected specularly, but is also scattered in all other directions.
The spatial000 parameters of the light beam interacting with a rough interface in
this case obviously change to a certain extent as compared to the case when radiation is incident on a smooth surface. However, the classical transport theory fails
to indicate how the spatial parameters of the beam may change when it intersects
the rough interface between two media [1]. Thus, the disregard of rough boundaries
in the transport theory requires the application of classical methods of the theory
of diffraction of electromagnetic waves from randomly rough surfaces. In this connection, it is important to. investigate the optical characteristics of the biological
structure taking roughness (when the characteristic size of roughness on the surface is much larger than the wavelength) with the help of the classical methods of
diffraction theory. A number of publications in which light scattering from a rough
surface was studied [1–4] are worth men tioning. For example, the scattering of light
from a rough surface with random Gaussian fluctuations of roughness was studied
© Springer International Publishing AG, part of Springer Nature 2018
K. Kulikov and T. Koshlan, Laser Interaction with Heterogeneous
Biological Tissue, Biological and Medical Physics, Biomedical Engineering,
https://doi.org/10.1007/978-3-319-94114-1_5
89
Study of the Optical Characteristics
of a Biotissue with Large-Scale
Inhomogeneities
Abstract We construct the electrodynamic model which makes it possible to vary
the electrophysical parameters of a biological structure in calculations with allowance
for roughness (real and imaginary parts of the refractive index of the epidermis, the
upper layer of the derma, and blood) and to establish the dependences between these
parameters and the biological properties of blood under the action of laser radiation
in vivo.
5.1 Introduction
It should be noted that the study of propagation of light in randomly inhomogeneous
media is mainly based on the classical methods of the transport theory. However,
the application of the radiation transport theory is not always effective in the study
of propagation of light in randomly inhomogeneous media (in particular, biological
media). It is well known that most biological surfaces are not planar but are rather
loose randomly rough media, in which the size of roughness are larger than the
wavelength of radiation illuminating them. The roughness of the surfaces affects the
characteristics of propagation and scattering of waves. A wave incident on a rough
surface is not only reflected specularly, but is also scattered in all other directions.
The spatial000 parameters of the light beam interacting with a rough interface in
this case obviously change to a certain extent as compared to the case when radiation is incident on a smooth surface. However, the classical transport theory fails
to indicate how the spatial parameters of the beam may change when it intersects
the rough interface between two media [1]. Thus, the disregard of rough boundaries
in the transport theory requires the application of classical methods of the theory
of diffraction of electromagnetic waves from randomly rough surfaces. In this connection, it is important to. investigate the optical characteristics of the biological
structure taking roughness (when the characteristic size of roughness on the surface is much larger than the wavelength) with the help of the classical methods of
diffraction theory. A number of publications in which light scattering from a rough
surface was studied [1–4] are worth men tioning. For example, the scattering of light
from a rough surface with random Gaussian fluctuations of roughness was studied
© Springer International Publishing AG, part of Springer Nature 2018
K. Kulikov and T. Koshlan, Laser Interaction with Heterogeneous
Biological Tissue, Biological and Medical Physics, Biomedical Engineering,
https://doi.org/10.1007/978-3-319-94114-1_5
89