Mathematical Model of Radiation Scattering on Quasi-Periodic Microstructure in Optical Fiber

The quasi-periodic structure of micro cavities formed under the fiber can be used as a scatterer in medical applications and as a sensitive element of fiber-optic sensors. Mathematical modelling of radiation propagation in an optical fiber with a quasi-periodic structure of micro cavities will make it possible to estimate the distribution of scattered radiation intensity along the quasi-periodic structure, as well as the intensity of reflected and transmitted radiation. This will make it possible to estimate the shape, size and geometry of the micro cavities and their location in the fiber core, providing the most optimal parameters of the scattered light flux. Modelling was carried out in the COMSOL Multiphysics package. A section of SMF-28e single-mode fiber with micro heterogeneities placed in the core was considered and the intensity distribution from the side surface of the fiber depending on the shape and size of the defect was evaluated. The report presents the results of the study with defects of different sizes and types.