Chapter 4
Speckle-Optical Methods and Devices
for Studying Human Skin and Muscle
Tissue
Theoretical and Experimental Prerequisites for Usage of Correlation Properties of
Dynamic Speckle-Fields in Medicine
Coherent optics, holographic interferometry, correlated spectroscopy, Doppler
anemometry, as well as speckle-photography and speckle-interferometry play an
important role in scientific study and development of new metrological means.
These speckle-optical methods, which are based on the study of correlated properties of optic fields, give the opportunity to determine such characteristics of objects,
which cause diffraction or radiation scattering as a degree of roughness, relief, shift,
deformations distribution, velocity, time of processes relaxation, etc. Recently, diffusive object interferometry is intensively developing, which was connected from the
very beginning with random interference phenomena—speckles. It is known [1] that
speckles appear as a result of interference of many elementary waves, spreading from
separate surface diffusers. As the number of such diffusers is great and they randomly
change the wave phase, then the resulting intensity distribution and the field phase
will be random and such a field can only be described with statistic methods. The
statistic character of reflection of coherent laser light from the rough surface, passing
through phase screens, turbulent medium, multi-mode waveguides, liquid crystals
and a number of other phenomena lead to forming a speckle-structure (Fig. 4.1).
If initially speckles were estimated as optical noise, then for about 20 years
new metrological methods have been developed on their basis, especially speckleinterferometry. Study of correlated characteristics of dynamic speckle-fields formed
by a moving diffusing object became a natural development of speckle-optics. Movement of the diffuser causes complex change of a speckle-field, which bears however
not a stochastic character, but as some studies showed [3–6], rather regular one.
Theoretical study of spatial and temporal correlations of speckle-fields becomes
complicated, because speckle-fields do not meet the condition of mutual spectral
frequency [7], and amplitude spatial and temporal correlated function do not decompose into a product of the spatial and the temporal parts. That is why time intensity
fluctuations cannot be analyzed independently from the spatial ones, as it occurs in
case of the Brownian movement of diffusing particles.
© The Author(s), under exclusive license to Springer Nature Switzerland AG 2021
L. Tanin et al., Biomedical and Resonance Optics, Bioanalysis 11,
https://doi.org/10.1007/978-3-030-60773-9_4
311
Speckle-Optical Methods and Devices
for Studying Human Skin and Muscle
Tissue
Theoretical and Experimental Prerequisites for Usage of Correlation Properties of
Dynamic Speckle-Fields in Medicine
Coherent optics, holographic interferometry, correlated spectroscopy, Doppler
anemometry, as well as speckle-photography and speckle-interferometry play an
important role in scientific study and development of new metrological means.
These speckle-optical methods, which are based on the study of correlated properties of optic fields, give the opportunity to determine such characteristics of objects,
which cause diffraction or radiation scattering as a degree of roughness, relief, shift,
deformations distribution, velocity, time of processes relaxation, etc. Recently, diffusive object interferometry is intensively developing, which was connected from the
very beginning with random interference phenomena—speckles. It is known [1] that
speckles appear as a result of interference of many elementary waves, spreading from
separate surface diffusers. As the number of such diffusers is great and they randomly
change the wave phase, then the resulting intensity distribution and the field phase
will be random and such a field can only be described with statistic methods. The
statistic character of reflection of coherent laser light from the rough surface, passing
through phase screens, turbulent medium, multi-mode waveguides, liquid crystals
and a number of other phenomena lead to forming a speckle-structure (Fig. 4.1).
If initially speckles were estimated as optical noise, then for about 20 years
new metrological methods have been developed on their basis, especially speckleinterferometry. Study of correlated characteristics of dynamic speckle-fields formed
by a moving diffusing object became a natural development of speckle-optics. Movement of the diffuser causes complex change of a speckle-field, which bears however
not a stochastic character, but as some studies showed [3–6], rather regular one.
Theoretical study of spatial and temporal correlations of speckle-fields becomes
complicated, because speckle-fields do not meet the condition of mutual spectral
frequency [7], and amplitude spatial and temporal correlated function do not decompose into a product of the spatial and the temporal parts. That is why time intensity
fluctuations cannot be analyzed independently from the spatial ones, as it occurs in
case of the Brownian movement of diffusing particles.
© The Author(s), under exclusive license to Springer Nature Switzerland AG 2021
L. Tanin et al., Biomedical and Resonance Optics, Bioanalysis 11,
https://doi.org/10.1007/978-3-030-60773-9_4
311