Vera I. Pozdnyakova

Coupling between elliptic screw polarization modes in single-mode optical waveguides with linear birefringence and regular twist of anisotropy axes in the presence of random axis twist

An analysis is made of single-mode fiber optical waveguides with linear birefringence and regular twist of anisotropy axes in the presence of random twist, which shows that, in this case, the coupling of orthogonal polarization modes having elliptic polarization in the screw coordinate system comoving with twist cannot be characterized by one coupling parameter, as differentiated from the case where constant twist is absent. In this case, the coupling between polarization modes is characterized by three independent parameters, which are different in nature and have different effects on the coupling of polarization modes. An estimate is made of the domain of applicability of the classical formula for the h parameter in single-mode fiber optical waveguides without regular twist of anisotropy axes.

The asymptotics of the polarization degree of non-monochromatic radiation travelling in fibre lightguides with random inhomogeneities

The paper is devoted to an analytical study of the degree of polarization of non-monochromatic radiation propagating in a fibre lightguide with random inhomogeneities at an infinite increase in the lightguides length. It is shown that an average value of the degree of polarization of non-coherent radiation passed through the fibre with random inhomogeneities tends to zero when the fibre length tends to infinity.

Random Groups in the Optical Waveguides Theory

Abstract We propose a new approach to the mathematical description of light propagation in a single-mode fiber light-guide (SMFLG) with random inhomogeneities. We investigate statistics of complex amplitudes of the electric field of light wave by methods of the random group theory. We have analyzed the behavior of the coherence matrix of a monochromatic light wave and the polarization degree of a nonmonochromatic radiation in SMFLG with random inhomogeneities as the length of the fiber tends to infinity; in particular, we prove that limit polarization degree is equal to zero.

Limiting Degree of Polarization of a Nonmonochromatic Radiation Propagating in a Fiber Guide with Random Inhomogeneities

It is shown that the mean degree of polarization of a nonmonochromatic radiation propagating in a fiber guide with random inhomogeneities tends to zero as the fiber length tends to infinity.

Effect of random orthogonal-mode coupling on polarization characteristics of monomode fibers (MF) and MF-based ring interferometers part IV. Zero drift in simplified fiber ring interferometers with nonmonochromaticradiation depolarizers

We considered four fiber-ring-interferometer (FRI) schemes without polarizers made of weakly anisotropic monomode fibers which differ from one another in the location of depolarizer of nonmonochromatic Lyot radiation from a highly anisotropic MF. The results of calculations conducted by numerical simulation with allowance for the h-parameter of the circuit and depolarizer MF show that the FRI zero drift is practically the same for all the four FRI circuits and strongly depends on the accuracy of setting of the angle of mutual orientation of the Lyot depolarizer elements. If the Lyot depolarizer is located at the FRI input (before the first beam splitter or between the first and second beam splitters), the interference signal fadings at the FRI output are practically not eliminated. If, however, the Lyot depolarizer is inside the FRI circuit (at one of its ends or in the middle), the interference signal fadings are, in practice, entirely eliminated, which makes these FRI circuits preferable.