In this work the abilities of a polymeric polyvinyl alcohol (PVA) films modified by ultradisperse silver nanoparticles to
polarized incident radiation and to form an illumination background close to diffuse scattering with the minimal power
losses were studied.
Regularities of changing of polarization characteristics of He-Ne laser radiation reflected and transmitted by
inhomogeneous media illuminated with super Gaussian or Bessel beams are investigated. As the inhomogeneous media
the (35 ± 5) μm thickness "cigarette" paper has been chosen.
The description of designed in the Institute of Physics of NAS of Belarus the device for measurement of attenuation factors of laser radiation attenuators is adduced. The measurement procedure, and realization of calculations and representation of uncertainties of the results of a measurement on the device MAPLR is stated. The results of an attenuator factor calculation for the mechanical attenuator, which is included in a complete set of the laser radiation power and energy meter NM0 -2H and its uncertainty are adduced.
The appearance of elliptical polarization for linear polarized radiation reflected by plant leaves was investigated. The leaf cuticle reflectance model was proposed. The evaluation of refractive index and mean angle of cuticle roughness to leaf surface was carried out.
The possibility of diagnostics of the composition and state of blood in a cuvette with plane-parallel walls by the polarization characteristics of the scattered laser radiation has been investigated. It has been shown experimentally, that the polarization characteristics of a scattered radiation at λ = 0.63 μm and under certain conditions of probing, linearly polarized in a plane of incidence by a laser radiation, and also observation are responsive to changes in structure and composition of a blood and can be used for the diagnostic purposes.
It was found that the radiation reflected by adaxial surface of leaf was elliptic polarization with maximum near Brewster. The ellipticity of reflected by leaves radiation increased with the increasing of mesophyll air spaces and the decreasing of leaf chlorophyll concentration. It can be explained that the non-polarized fraction of light from internal structure depends on the leaf pigments concentration and the quantity of air spaces in mesophyll.
It has been shown experimentally, that the polarization characteristics of a scattered radiation at λ=0,63 μm and under certain conditions of probing, linearly polarized in a plane of incidence by a laser radiation, and also observation are responsive to changes in structure and composition of blood and can be used for diagnostic purposes.
The possibility of diagnostics of the composition and state of blood in a cuvette with plane-parallel walls by the polarization characteristics of the scattered laser radiation has been revealed. It has been established experimentally that the use of λ = 0,63 μm laser radiation linearly polarized in the plane of incidence under certain conditions of probing and observation makes it possible to minimize the distortion of the parameters of the radiation scattered by the sample in the cuvette by its boundaries. We have found the range of recording angles, which provides the widest interval of changing the degree of polarization characterized by the two first Stokes parameters of the radiation scattered by the blood in the case of changing its state.
A laser nephelometer for determination of Mueller matrices of the optical properties of objects transforming radiation has been designed. The nephelometer scheme and operation method are described. There have been derived formulas for matrix elements calculation with operating of the nephelometer designed. The polarization characteristics of the probing radiation in the nephelometer are changed by different setting of the first waveplate retarder, and the polarization analysis of the scattered light is carried out with the use of the Fourier expansion of the signal recorded by a photodetector in the process of rotation of the second retardation waveplate retarder placed in front of an immovable analyzer. The absolute error of the Mueller matrix elements measurement have been determined experimentally.
Systematic errors of the Mueller matrix elements for optical properties of objects caused by a misalignment of initial positions of waveplates principal directions and an analyzer transmission axis are considered. The examination is made for the device, in which the probing radiation polarization properties change at different installations of the first waveplate, and the polarization analysis of a scattered light is carried out using a Fourier series expansion of a signal, which one is produced by a photodetector at a rotation of the second waveplate placed before the fixed analyzer. The estimating equations of these errors arising at a separate misalignment of anisotropic optical elements in illuminating and perceiving radiation channels of the measuring device, and equations on which it is possible to judge about a correctness of these anisotropic elements setting are derived. Combined influence of different inaccuracies of anisotropic element installations is considered by the mathematical simulation method and it is compared to experimentally determined behavior of the Mueller matrix elements measurement systematic errors depending on a misalignment of initial position of the first waveplate principal directions.
The results of investigation of the Stokes parameters of He- Ne-laser radiation reflected by different zones of the material precipitated from the plasma torch formed by the interaction of the linearly polarized pulse Nd-laser radiation with a solid target (tantalum) are presented. It was found out, that the intensity ndicatrixes of reflected radiation depends on the deposited layer position. The dependencies of reflection character of the probing radiation on the types of the mentioned above layers are presented.
It is shown that the largest differences in the angular distribution and meanings of the polarization characteristics of radiation reflected by different plant's leaves are observed for leaves illuminated at the angle of 55 degrees by a He-Ne laser radiation ((lambda) equals 0.63 micrometer) linearly polarized in the plane of incidence. It has been revealed that radiation reflected by a leaf becomes elliptically polarized at observation angles of 55 degrees plus or minus 10 degrees. The ellipticity of radiation reflected by leaves depends on the leaf thickness and the position of the top or bottom of the leaf surface relative to the direction of illumination.
The Stokes parameters of He-Ne laser radiation ((lambda) equals 0.63 micrometer) reflected at the angles of incidence from 5 to 70 degrees by glass reinforced silicon polymer before and after its heating up to 1200 K by CW CO2-laser radiation were measured. The He-Ne laser radiation was linearly polarized either parallel, or perpendicular to the plane of incidence. It is shown that radiation reflected in the specular direction by samples illuminated at near the Brewster angle ((theta) approximately equals 56 degrees) by radiation linearly polarized in the plane of incidence contains an elliptically polarized component. Simultaneously, the change of polarization azimuth of reflected radiation is observed.
The dynamic type Stokes polarimeter is created to measure the polarization characteristics of radiation emitted, reflected, and scattered by objects at different angles to the surface. An analysis of the versions of processing of measurement results has shown that the dependence of a random error in determination of the parameters on the number of positions N of a quarter-wave plate, at which the radiation intensity is measured, is of a similar nature as the dependence on the number of independent measurements of the same quantity (approximately 1/(root)N).
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