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11.
The weakly nonlinear boundary value problem of wave propagation in an optical fibere(for the transverse electric mode,for example)is formulated and a modified linear solution is obained.It is shown that a self-consistent theory of fibre optics should be weakly nonlinear,The mode of critical refraction that does not exist in the linear theory is obtained,showing that it is a mode consisting of resonance modes,It is shown that the signal carriers in a long fibre are of resonance modes,not normal modes,Some experimental data are given for comparison with the theoretical predictions and the agreement seems satisfactory. 相似文献
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Anatoli Andrei Vankov 《Foundations of Physics》2008,38(6):523-545
In relativistic theories, the assumption of proper mass constancy generally holds. We study gravitational relativistic mechanics
of point particle in the novel approach of proper mass varying under Minkowski force action. The motivation and objective
of this work are twofold: first, to show how the gravitational force can be included in the Special Relativity Mechanics framework,
and, second, to investigate possible consequences of the revision of conventional proper mass concept (in particular, to clarify
a proper mass role in the divergence problem). It is shown that photon motion in the gravitational field can be treated in
terms of massless refracting medium, what makes the gravity phenomenon compatible with SR Mechanics framework in the variable
proper mass approach.
Specifically, the problem of point particle in the spherical symmetric stationary gravitational field is studied in SR-based
Mechanics, and equations of motion in the Lorentz covariant form are obtained in the relativistic Lagrangean problem formulation.
The dependence of proper mass on potential field strength is derived from the Euler-Lagrange equations as well. One of new
results is the elimination of conventional 1/r divergence, which is known to be not removable in Schwarzschild gravitomechanics. Predictions of particle and photon gravitational
properties are in agreement with GR classical tests under weak-field conditions; however, deviations rise with potential field
strength. The conclusion is made that the approach of field-dependent proper mass is perspective for development of SR gravitational
mechanics and further studies of gravitational problems. 相似文献
14.
Amphoteric refraction of light ray at the interface between isotropic materials and anisotropic materials is analyzed. Depending on the incident angle, the refractive light ray can either refract positively or negatively. This amphoteric refraction phenomenon can be quite prevalent when the difference of the two principal refractive indices is large. The reflectance under various incident angles has also been calculated, and an experimental demonstration with a calcite crystal in air is presented. 相似文献
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We report on third order optical nonlinear experimental characterization using Z-scan method through focal shift measurements of a converging lens. The sample is fixed in front of a lens and is illuminated by a collimated beam. The shift of the geometrical focus in the nonlinear regime using input Gaussian beams is related to the nonlinear induced dephasing owing to a simple linear relation. Numerical calculations based on the Helmholtz wave equation are performed. Good agreement is obtained between experimental and theoretical results. 相似文献
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本文从“同温度层不完全平行于地面,且在变化”的“任意分层”假设出发,导出了水准折光修正公式,并利用光的色散效应在10~(-6)的精度要求下,求得r=r_T=h_1/h_2=(n_(01)-1)/(n_(02)-1)=常数最后指出,研制双波长激光水准仪的必要性和可能性,并提出了研制此种仪器的技术参数. 相似文献
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《Comptes Rendus Physique》2016,17(5):533-542
The negative refraction behavior and imaging effect for acoustic waves in a kind of two-dimensional square chiral lattice structure are studied in this paper. The unit cell of the proposed structure consists of four zigzag arms connected through a thin circular ring at the central part. The relation of the symmetry of the unit cell and the negative refraction phenomenon is investigated. Using the finite element method, we calculate the band structures and the equi-frequency surfaces of the system, and confirm the frequency range where the negative refraction is present. Due to the rotational symmetry of the unit cell, a phase difference is induced to the waves propagating from a point source through the structure to the other side. The phase difference is related to the width of the structure and the frequency of the source, so we can get a tunable deviated imaging. This kind of phenomenon is also demonstrated by the numerical simulation of two Gaussian beams that are symmetrical about the interface normal with the same incident angle, and the different negative refractive indexes are presented. Based on this special performance, a double-functional mirror-symmetrical slab is proposed for realizing acoustic focusing and beam separation. 相似文献