Hnatenko O. Mode-locking in the Fiber Laser based on Liquid Crystal Cells

The object - mode-locking of fiber laser radiation. The purpose – development of the method of mode locking in a fiber laser based on the use of controlled LC cells. Methods – modelling of the process of ensuring the stability of polarization of modes in a ring fiber laser was carried out using the analytical method and the method of expansion in physical quantities with a fast Fourier transform; numerical modelling using the Oseen-Frank equation of the process of controlling the polarization of laser radiation using LC cells; experimental studies of mode-locking of a fiber laser using LC cells. Results – the theoretical model of mode-locking of a fiber laser was further developed; the conditions for the stability of the polarization of longitudinal modes in a ring fiber laser using liquid crystal cells have been experimentally investigated; an experimental model of a fiber laser was developed, which made it possible to obtain linearly polarized radiation at a wavelength of 1.55 μm with a pulse duration of the femtosecond order; it is shown that the developed system has significantly improved performance due to the increased efficiency of the polarization rotation angle adjustment using LC cells. Scope – physical research, instrumentation, information technology.