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Information × Registration Number 0211U002971, 0109U006071 , R & D reports Title Optimal modal representations in direct and inverse problems of field transformation in optical wave guiding elements and systems. popup.stage_title Head Kurashov V.N., Registration Date 15-03-2011 Organization Taras Shevchenko Kiev university popup.description2 The problem of eigen mode conversion in air clad planar and fiber waveguides with a random rough surface is analyzed in for a case of high refraction index contrast and Gaussian statistics of the glass/air interface. The theoretical model of radiation losses in planar and fiber waveguides with rough surface is proposed. The losses are studied theoretically in assumption, that the glass/air interface has the structure of the frozen capillary wave. It is demonstrated that the scattering of the fundamental TE0 mode of the planar waveguide by the stochastic core/cladding bound results in incoherent excitation of TM modes, which are polarized orthogonally with respect to the basic one. The intensity of mode conversion at the perturbed core/cladding bound of the dielectric waveguide is strongly dependent on its refraction index contrast. It is proved that the relation between the intensity of scattered light and the spectral density of the roughness is of nonlinear character. The conversion of the fundamental mode of the fiber waveguide into orthogonally polarized modes is studied. The conditions, when the phenomenon becomes considerable, are established. The effect of birefringence at the polarization phenomena in the fiber waveguide with the square law profile of the refractive index is investigated. The difference in polarization changes is demonstrated for the cases of the strong and weak birefringence. The roughness of air clad optical fiber is studied experimentally by means of AFM. The roughness spectrum is estimated and compared with the model of the frozen capillary wave. The hypothesis of the Gaussian statistics of the roughness is tested. Product Description popup.authors Данько Володимир Петрович Кисіль Олександр Васильович Коваленко Андрій Віленович Курашов Віталій Наумович popup.nrat_date 2020-04-02 Close