共查询到20条相似文献,搜索用时 609 毫秒
1.
N. I. Petrov 《Journal of Experimental and Theoretical Physics》1997,85(6):1085-1093
The depolarization and rotation of the polarization plane of radiation propagating in a two-dimensional graded-index medium
is investigated on the basis of the quantum-mechanical method of coherent states. It is shown that the degree of polarization
of both linearly and circularly polarized radiation decreases with increasing distance as a result of interaction between
the polarization (spin) and the path (orbital angular momentum) of the beam. The wave nature of the depolarization is emphasized.
The depolarization decreases as the radiation wavelength decreases. It is found that the degree of polarization exhibits oscillations
of pure diffraction origin during the propagation of light in a single-mode optical fiber. It is shown that the rotation of
the polarization plane is nonuniform in character and depends on the offset and the tilt angle of the incident-beam axis relative
to the fiber axis. The Berry phase is found to undergo oscillations of a wave nature during the propagation of radiation in
an inhomogeneous medium. It is shown that the spread in the angle of rotation of the polarization plane increases with distance
and can be determined from measurements of the degree of polarization of the radiation.
Zh. éksp. Teor. Fiz. 112, 1985–2000 (December 1997) 相似文献
2.
生物组织内部结构复杂且具有较强的散射特性,而光作为生物组织检测的重要信息载体,其自身特性包括颜色、幅值、偏振等都对信息获取有较大的影响.结合偏振成像,对生物组织多光谱偏振特性展开了研究,依据不同微粒尺寸的分布建立了均匀单层生物组织模型,结合瑞利和米氏散射理论模拟了基于单个微粒的两种散射事件.瑞利散射具有较好的前向后向散... 相似文献
3.
A. P. Ivanov 《Optics and Spectroscopy》2009,107(2):171-183
As light passes through scattering media, certain specific features of the polarization of radiation manifest themselves.
The paper presents materials on this problem that were obtained at the Institute of Physics of the National Academy of Sciences
of Belarus over recent decades. Results of experimental investigations of media that model real objects are described for
the case where the dimensionless optical parameters of media and objects coincide. A method for determining the position of
a diffuse light source in the atmosphere via predominant oscillations of the light vector of scattered radiation for two directions
of observation is proposed. The structure of aerosol formations (smokes, dust and liquid-droplet and crystalline clouds) is
interpreted based on the character of depolarization of laser radiation sounding atmosphere. The polarization of laser radiation
passing through a turbid medium and reflected from it is studied. Practical applications are proposed. Fundamentals of an
applied vector theory of radiation transfer, which made it possible to considerably expand notions of light scattering in
strongly turbid media, are given. Studies of light propagation in encapsulated liquid crystals, which are used for solving
of a large number of problems, are described. In these objects, ordinary and extraordinary rays that arise in crystals under
electric voltage can give rise to a wave that is attenuated to a different degree and whose phase and polarization characteristics
are varying. 相似文献
4.
《中国光学快报(英文版)》2016,(1)
A polarization holographic grating, which integrates the functions of a grating and a wave plate and is called a diffractive wave plate, is recorded by two beams(left and right circularly polarized) of a 532 nm laser in an azo polymer with a liquid-crystal structure. The polarization conversion characteristics of the diffractive wave plates are investigated with a detecting light of 650 nm by metering the polarization state of first-order diffracted light.It is confirmed that the diffractive wave plates convert the incident linear polarization into circular polarization for a linearly polarized probe laser and reverse the sense of rotation of the circular polarization when the detecting light is circularly polarized light. 相似文献
5.
J.N. Swamy Czarena Crofcheck 《Journal of Quantitative Spectroscopy & Radiative Transfer》2007,104(2):277-287
A Monte Carlo ray tracing scheme is used to investigate the propagation of an incident collimated beam of polarized light in liquid foams. Cellular structures like foam are expected to change the polarization characteristics due to multiple scattering events, where such changes can be used to monitor foam dynamics. A statistical model utilizing some of the recent developments in foam physics is coupled with a vector Monte Carlo scheme to compute the depolarization ratios via Stokes-Mueller formalism. For the simulations, the incident Stokes vector corresponding to horizontal linear polarization and right circular polarization are considered. It is observed that bubble size and the polydispersity parameter have a significant effect on the depolarization ratios. This is partially owing to the number of total internal reflection events in the Plateau borders. The results are discussed in terms of applicability of polarized light as a diagnostic tool for monitoring foams. 相似文献
6.
It is shown that all optical polarization states of light except plane and circular polarization states undergo an intensity-dependent
change in normal incidence of light in an isotropic nonlinear Kerr medium. This effect should be detectable and we propose
an experiment for detecting nonlinear susceptibility involved in that part of nonlinear polarization, which depends on the
polarization state of light also. 相似文献
7.
On the basis of the beam tensor formalism proposed by F. I. Fedorov, the theory of polarization selfaction of radiation in isotropic resonant media is extended to the case of partial elliptic polarization of an electromagnetic wave. The influence of the degree of radiation polarization on the known polarization self-action effects is demonstrated and the self-polarization (depolarization) of light is predicted. 相似文献
8.
非球形气溶胶是影响辐射传输的重要因素. 系统给出了矢量辐射传输Monte Carlo模型, 并验证了其准确度; 考虑入射光偏振态, 讨论了不同方向漫射光Stokes矢量对气溶胶形状的敏感性; 分析了气溶胶形状、入射光偏振状态对光波退偏振度、透过率及反射率的影响. 模拟仿真结果表明, 对于不同偏振态的入射光, 不同方向的Stokes矢量对气溶胶形状变化的灵敏程度并不一致, 而在天顶角0°方向区域,Q, U及V分量对形状的灵敏程度普遍不高; 气溶胶形状对反射漫射光退偏程度的影响强于透射漫射光, 入射光偏振态不同, 漫射光退偏程度也存在较大差异. 气溶胶形状对光波整体透过率与反射率影响显著, 且该影响随传播距离增大而增大; 入射光偏振态对透过率与反射率影响相对较小, 与自然光相比, 水平偏振光透过率略偏小, 反射率略偏大, 垂直偏振光反之, 圆偏振光与自然光的模拟结果相当. 相似文献
9.
D. Budaszewski A. W. Domański A. Czapla S. Ertman T. R. Woliński T. Nasilowski H. Thienpont 《Opto-Electronics Review》2009,17(2):156-160
In the paper we analyze microstructured optical fibers filled with typical nematic liquid crystals, i.e., 5CB and 6CHBT under
influence of external electric field or temperature. We use the modified Mueller matrix method with an additional depolarization
matrix to calculate degree of polarization changes of the light propagating in the liquid-crystal infiltrated microstructured
optical fibers. Preliminary experimental results of light depolarization measurements during propagation in these microstructured
fibers are also presented. 相似文献
10.
Shuichi Makita Yoshiaki Yasuno Yasunori Sutoh Masahide Itoh Toyohiko Yatagai 《Optical Review》2003,10(5):366-369
Polarization-sensitive spectral interferometric optical coherence tomography (PS-SI-OCT) is designed for imaging of the inner structure of a biological tissue with polarization properties corresponding to Müller matrix elements. With arbitrary polarization state of incident and reference light, the change of polarization state can be acquired, and the axial structure of the tissue is measured by single detection of the power spectrum, superposition of object and reference light. Using with this OCT system, a cross-sectional Müller matrix images of human skin can be observed. 相似文献
11.
The results from experimental studies of the magnetooptical Kerr and Faraday effects in Co-P films are described. It is shown
that the angle of rotation of the polarization of light in the polar Kerr effect is a nonmonotonic function of film thickness.
Maximum changes in the angle of rotation are observed in the wavelength region of incident radiation for thicknesses comparable
to the skin layer. A qualitative model in which the observed effects are attributed to the multilayer structure of the samples
under study is described. 相似文献
12.
13.
A. A. Gevorgian 《Technical Physics》1999,44(8):935-940
Results are presented on the polarization characteristics (rotation of the plane of polarization and polarization ellipticity)
as a function of the layer thickness and the absorption anisotropy in strongly absorbing media having a helical structure.
A strong resonancelike change in the polarization ellipticity is found as a function of the anisotropy of the absorption at
frequencies of diffractional interaction of the light with the medium. A change in the sign of rotation of the plane of polarization
of the light is observed as the layer thickness is varied. It is established that sign of the rotation also changes as the
absorption anisotropy varies. These effects are studied under conditions of interaction of light with a half space and with
a layer of medium of finite thickness. Some new features are identified in the previously observed effect wherein the absorption
of radiation in media having a periodic structure decreases as the layer thickness increases.
Zh. Tekh. Fiz. 69, 72–78 (August 1999) 相似文献
14.
Distributions of the spectral density of the dependence of the phase difference of counterpropagating waves in a fiber ring interferometer (FRI) on the temperature of the single-mode optical fiber (SMOF) in the FRI loop (temperature spectra of the FRI zero drift) due to polarization nonreciprocity have been obtained by Fourier analysis for different spectral linewidths of the FRI radiation source and different linear birefringences of the SMOF in the FRI loop. It is shown that a change in the temperature of the SMOF in the FRI loop changes mainly the SMOF linear birefringence. This effect leads to a change in the phases of the radiation that is transferred from one polarization mode to another at those points in the SMOF where the random twisting of the axes of unperturbed linear birefringence of the SMOF changes. The effect of the magnitude of the jump under consideration, its location with respect to the nearest FRI loop end, and the magnitude of the cross-correlation (visibility) function of the radiation transmitted along the slow and fast SMOF axes from the loop end to the point where a jump in twisting of the SMOF axes occurs on the character of the temperature spectra of the FRI zero drift is determined. It is shown that in the case where the depolarization length of nonmonochromatic radiation in an SMOF is smaller than the average length of the SMOF segment on which random twisting is constant, the qualitative and quantitative characteristics of the temperature spectra of the FRI zero drift depend strongly on the polarization state of the radiation at the input of the FRI loop. The reason for this difference is explained. 相似文献
15.
A. G. Ushenko 《Optics and Spectroscopy》2000,89(4):597-600
The formation of a fine polarization structure of biospeckles of derma is studied. In the case of scattered laser radiation, the degree of polarization is shown to be an integrated characteristic of randomly distributed types and forms of polarization of an ensemble of biospeckles. A method for phase compensation of the degree of depolarization is proposed, which makes possible a severalfold increase of the measurement sensitivity. 相似文献
16.
V. P. Karassiov 《Physics of Particles and Nuclei Letters》2009,6(7):572-576
We study kinematic and dynamic ways of forming entangled states of quantum light fields due to their local and global polarization
SU(2) symmetries. The kinematic entanglement is shown to be associated with particular polarization bases in the spaces of quantum
states of multi-mode radiation, which are generated by the global SU(2) — symmetry. Dynamic entanglement is due to SU(2) symmetries of the Hamiltonians of the matter-radiation interaction. We also define some entanglement measures, which are
related to characteristics of light depolarization. Applications of results obtained in biphoton optics are briefly discussed. 相似文献
17.
Petrov M. P. Voitylov V. V. Klemeshev S. A. Trusov A. A. 《Optics and Spectroscopy》2011,111(5):832-840
We present the results of our experimental investigation of light scattering by polydisperse colloids of diamond and graphite.
The scattering is studied at a random orientation of particles and in an external radiofrequency electric field, which orients
particles along the strength. The average dimensions of particles in both colloids are close to each other and comparable
with the wavelength of the incident light. The shape of particles and the optical and electrooptical properties of diamond
and graphite colloids are significantly different. We analyze the polarization components of scattered light energy when the
light incident on the colloids is linearly polarized. We show that the quadrupole light scattering by isotropic diamond particles
has the main effect on angular dependences of depolarization of scattered light. For light scattering by anisotropic graphite
particles, the depolarization of scattered light is mainly determined by a particular feature of the dipole scattering of
particles. It is shown that, in both colloids, the orientational order of particles considerably reduces the depolarization
of light scattered by particles. We show that relative changes in the intensity and depolarization of scattered light, which
depend on the scattering angle and polarization direction of light, as well as on the parameters of particles, can be used
as a measure of electrooptical effects observed in colloids. 相似文献
18.
针对传统被动水下偏振成像方法忽略水体对光的吸收效应,成像结果中存在严重的色彩失真,且并未深入发掘利用背景散射光中包含的场景信息的问题.提出浅海被动水下偏振成像探测方法,该方法从水体中背景散射光的传输特性出发,分析场景深度信息与散射光的物理关系,建立基于深度信息的水下Lambertian反射模型,实现无色彩畸变的水下目标场景清晰成像探测.实验结果表明,该方法能够提供接近水下目标真实色彩、符合人眼视觉特性的清晰探测结果,提高水下成像探测能力. 相似文献
19.
Depolarization properties of cirrus clouds from polarization lidar measurements over Hefei in spring
A new polarization lidar has been developed for detecting depolarization characteristics of aerosol and cirrus over Hefei (31.90°N, 117.16°E), China. The fundamental principle of polarization lidar is briefly introduced. 相似文献
20.
We present a method for detecting nonmelanoma skin cancers using exogenous fluorescence polarization. We built an automated system that permits exogenous fluorescence polarization imaging. It includes a tunable linearly polarized monochromatic light source and a CCD camera equipped with a rotating linear polarizer and a filter to reject excitation light. Two fluorophores that are retained in tumors, toluidine blue and methylene blue, are employed. We demonstrate that fluorescence polarization imaging can be used for accurate delineation of nonmelanoma cancers. The results suggest that this optical technique may be suitable for real-time noninvasive demarcation of epithelial cancers. 相似文献