INFLUENCE OF TECHNOLOGICAL IMPERFECTION OF CORE ON THE STRESS STATE AND OPTICAL CHARACTERISTICS OF PANDA FIBER
By method of statistical analysis studied series of geometry parameters of the panda fibers cores. Determined that ellipse is the most probability form. Were obtained distribution laws and average values of these geometrical parameters. Has been performed formulation of the problem about the effect of geometry deviations of the fiber core from the design values on the stress-strain state and modal birefringence. The mathematical model was described and on the basis of it was performed the numerical analysis of residual stress fields in the Panda fiber for possible variants of geometry of the fiber core. The dependences of the modal birefringence on the roundness and orientation of the fiber core are obtained. It is established that, for a given core roundness larger birefringence is realized when the orientation of the major axis of the ellipse same as the direction of arrangement of the stress applying rods, and the minimum value corresponds to the perpendicular orientation. It has been shown, that increasing of the core ellipticity leads to increase the birefringence, when the orientation of the major axis of the ellipse same as the direction of arrangement of stress applying rods, and respectively, to reduce the birefringence in the case of perpendicular orientation.