共查询到20条相似文献,搜索用时 281 毫秒
1.
Yoshiaki Yasuno Yasunori Sutoh Shuichi Makita Masahide Itoh Toyohiko Yatagai 《Optical Review》2003,10(5):498-500
A spectral interferometric optical coherence tomography (OCT) system which has polarization sensitivity is developed. This system reduces the mechanical scanning dimension by employing the principle of spectral interferometry, and measures a two dimensional cross-sectional image of biological tissue with one dimensional mechanical scanning. Sixteen OCT images with different polarization conditions are measured, and two dimensional distributions of each element of the Müller matrix of a sample to be measured are calculated. 相似文献
2.
Shuichi Makita Yoshiaki Yasuno Takashi Endo Masahide Itoh Toyohiko Yatagai 《Optical Review》2005,12(2):146-148
A polarization-sensitive Fourier domain optical coherence tomography (PS-FD-OCT) system has been developed. By using a two-dimensional CCD camera, this PS-FD-OCT simultaneously obtains two spectral interferograms corresponding to orthogonal polarization components of a probing beam. FD-OCT avoids axial mechanical scanning, therefore, two OCT images are obtained by a single lateral scanning. This system requires only two one-dimensional scannings for determining the Müller matrix images of a sample. In the Müller matrix images, the birefringence properties of the inner surface of a porcine esophagus are revealed. 相似文献
3.
An alternate crystal structure for YBa2Cu3O7 recently proposed by Reller, Bednorz and Müller has been examined by the profile analysis. Although the proposed structure can explain the X-ray data, that model is incompatible with the result of the neutron diffraction experiment. 相似文献
4.
5.
Grounds and applications of Bargmann-Michel-Telegdi equations for the precession of the polarization vector of relativistic particles are considered. A critical question in the discussion is the orientation of the rest frame reference vectors. Møller reference frames which keep constant the mutual orientation of the two infinitely close in time rest frames are shown to have a special role. The generally covariant form of the equations is discussed. The assertion that the principle of relativity is violated in the phenomenon of spin precession is proved to be untrue. 相似文献
6.
7.
S. N. Savenkov E. A. Oberemok S. A. Mamilov S. S. Esman M. M. Asimov 《Journal of Applied Spectroscopy》2011,78(1):87-94
Results from numerical calculations and experimental studies of the optical backscattering coefficients and changes in the
polarization characteristics of normal and modified (birthmark, scar) skin tissue structures are presented. It is shown that
determining the Mueller matrix is an effective way of detecting changes in the structure of skin tissue in vivo which reflects
changes in the depolarization of light by an object for different polarization parameters of the incident (probe) radiation.
The depolarization of light is found to be symmetric for normal areas of skin and antisymmetric for skin tissue with a modified
structure. It is proposed that the polarization characteristics of scattered radiation be used in detecting damaged areas
of skin tissue. 相似文献
8.
Sagnac fiber optic current sensor (S-FOCS) is a kind of optical interferometer based on Sagnac structure, optical polarization states of sensing light wave in Sagnac fiber optic current sensor are limited. However, several factors induce optical polarization error, and non-ideal polarized light waves cause the interference signal crosstalk in sensor, including polarizer, quarter-wave retarder, splice angular, birefringence and so on. With these errors, linearly polarized light wave in PM fiber and circularly polarized light wave in sensing fiber become elliptically polarized light wave, then, nonreciprocal phase shift induced by magnetic field of the current is interrupted by wrong polarization state. To clarify characteristics of optical polarization error in fiber optic current sensor, we analyze the evolution process of random optical polarization state, linear optical polarization state and circular optical polarization state in Sagnac fiber optic current sensor by using Poincare sphere, then, build optical polarization error models by using Jones matrix. Based on models of polarization state in Sagnac fiber optic current sensor, we investigate the influence of several main error factors on optical polarization error characteristics theoretically, including extinction ratio in polarizer, phase delay in quarter-wave retarder, splice angular between quarter-wave retarder and polarization maintaining fiber. Finally, we simulate and quantify nonreciprocal phase shift to be detected in fiber optic current sensor related with optical polarization errors. In the end, we demonstrate S-FOCS in test. The results show that transfer matrix errors are induced by inaccurate polarization properties during polarization state conversion, then, the stability and accuracy of the S-FOCS are affected, and it is important to control the polarization properties at each step of the polarization state conversion precisely. 相似文献
9.
Mike Nicholas 《Journal of computational physics》2010,229(21):8211-8223
We develop a highly accurate numerical method for scattering of 3D electromagnetic waves by doubly periodic structures. We approximate scattered fields using the Müller boundary integral formulation of Maxwell’s equations. The accuracy is achieved as singularities are isolated through the use of partitions of unity, leaving smooth, periodic integrands that can be evaluated with high accuracy using trapezoid sums. The removed singularities are resolved through a transformation to polar coordinates. The method relies on the ideas used in the free space scattering algorithm of Bruno and Kunyansky. 相似文献
10.
G. Nilsson C. Anderson J. Henricson M. Leahy J. O’Doherty F. Sjöberg 《Opto-Electronics Review》2008,16(3):309-313
A new and versatile method for tissue viability imaging based on polarization spectroscopy of blood in superficial tissue
structures such as the skin is presented in this paper. Linearly polarized light in the visible wavelength region is partly
reflected directly by the skin surface and partly diffusely backscattered from the dermal tissue matrix. Most of the directly
reflected light preserves its polarization state while the light returning from the deeper tissue layers is depolarized. By
the use of a polarization filter positioned in front of a sensitive CCD-array, the light directly reflected from the tissue
surface is blocked, while the depolarized light returning from the deeper tissue layers reaches the detector array. By separating
the colour planes of the detected image, spectroscopic information about the amount of red blood cells (RBCs) in the microvascular
network of the tissue under investigation can be derived. A theory that utilizes the differences in light absorption of RBCs
and bloodless tissue in the red and green wavelength region forms the basis of an algorithm for displaying a colour coded
map of the RBC distribution in a tissue. Using a fluid model, a linear relationship (cc. = 0.99) between RBC concentration
and the output signal was demonstrated within the physiological range 0–4%. In-vivo evaluation using transepidermal application
of acetylcholine by the way of iontophoresis displayed the heterogeneity pattern of the vasodilatation produced by the vasoactive
agent. Applications of this novel technology are likely to be found in drug and skin care product development as well as in
the assessment of skin irritation and tissue repair processes and even ultimately in a clinic case situation. 相似文献
11.
A previously investigated model of a two band superconductor with hybrid pairing and molecular fields is enlarged by exchange interactions generating those fields. The fields are calculated selfconsistently in molecular field approximation at zero temperature. They turn out to stabilise the previously found new state of gapless superconductivity and non vanishing spin polarization for a wide range of exchange couplings, in particular for zero external field.Dedicated to B. Mühlschlegel on the occasion of his 60th birthdayWork performed within the research program of Sonderforschungsbereich 125 Aachen-Jülich-Köln 相似文献
12.
13.
The digital holographic technique is applied to analyze the spatial distribution of polarization state of light transmitted
through anisotropic objects using an orthogonal linearly polarized reference beam. The polarization orientation of reference
beam is switched by an optical fiber Faraday rotator for successive hologram recording. To confirm the principle of polarization
analysis, a quarter wave plate (QWP) is used and the distribution of polarization state over the object surface is analyzed
for various orientations of the QWP. By providing an area of a known polarization for a part of the object wave as a reference,
a phase drift of the reference waves can be evaluated and compensated for using the reference area. The principal axis and
ellipticity of polarization ellipse are calculated and compared with their theoretical values. A good agreement between the
experimental and theoretical values is observed. 相似文献
14.
A numerical study of the state and degree of polarization along single-polarization fibres has been carried out on the basis of Müller-Stokes matrix approach and the mode coupling centre model. The general quasimonochromatic case is considered. Correspondence between polarization holdingh-parameter and the mode coupling centres' parameters has been established. The spectral average process has been considered and a novel criterion has been proposed. Expressions for the degree of polarization along the fibre have been derived for the cases of guided mode excitation and nonpolarized input. The degree of polarization has been shown to tend to a saturation level which depends on theh-parameter, the differential mode attenuation gD and the coherence lengthL
in the fibre. 相似文献
15.
An unusual peak has been found by Müller et al. for the attenuation of longitudinal sound as a function of temperature around 12 K for UPt3. Breathing mode coupling of the volume strain to the electronic energy states of a narrow band of high density at the fermi energy seems to be the origin of this peak. 相似文献
16.
Mauricio Suárez 《Foundations of Physics Letters》1996,9(5):425-435
Albert and Loewer have argued in this journal [4] that modal interpretations of quantum mechanics are ruled out if the abstract structure of Hilbert space is taken realistically. Their argument contains a dubious inference from a measure-zero set of non-ideal interactions. I look at possible ways to make this inference valid and I conclude that the evidence against the modal interpretation cannot be found in the Hilbert space alone. Instead an analysis of specific cases is required.I want to thank the audience at the 1995 Florence IUHPS Conference, and Harvey Brown, Nancy Cartwright, Jim Cushing, Marco Del Seta, Arthur Fine, Margaret Morrison, Fred Müller and Pieter Vermaas for comments and suggestions. 相似文献
17.
18.
We have developed a spectral interferometric optical coherence tomography (OCT) system with polarization sensitivity that is able to measure a two-dimensional tomographic image by means of one-dimensional mechanical scanning. Our system, which has an axial resolution of 32 mum , calculates the distribution of each element of the Müller matrix of a measured object from 16 OCT images. The OCT system successfully reveals the birefringent nature of human skin tissue. 相似文献
19.
偏光显微镜中偏振态的理论分析 总被引:2,自引:1,他引:1
为了更好地利用偏光显微镜检测光通过透明光学晶体材料后偏振态的变化,研究和鉴定晶体的光学特性,从介绍偏光显微镜的光学结构入手,分析了自然光通过偏光显微镜的几何光路,然后利用Stocks参量和Muller矩阵分析自然光通过偏光显微镜的偏振态变换,从理论上给出了出射光偏振态变化的原理,并利用计算机模拟了光强随各参数的变化曲线,分析了干涉图像形成的过程。对在实践中使用偏光显微镜测量晶体薄片的双折射率、延长符号、分析材料的光学特性以及观察材料的结构更具有指导性的意义。 相似文献
20.
J. P. Wesley 《Foundations of Physics Letters》1990,3(5):471-490
Weber electrodynamics predicts the localized unipolar induction observed by Müller and Kennard; whereas the Maxwell theory, based upon closed current loops and the flux rule, fails. The Weber theory for high frequency fields predicts a zero self torque on the Pappas-Vaughan Z-antenna, as observed. In contrast, the Maxwell theory predicts a sizeable self torque which is not observed. 相似文献