Investigation of the generation characteristics of an optical fiber for modeling an ytterbium pump laser with a wavelength of 1125nm

The results of experimental and theoretical studies of the fiber laser based on active Yb3+ fibers are presented. It is shown that the design parameters, such as the length of the fiber resonator and the reflection coefficient of the Bragg gratings, in a continuous laser can be predetermined by simulation. An analytical solution for the output power of the laser is obtained. The modeling results are compared with experimental data. The dependences of the output power on the active fiber length and the reflection coefficient of the output Bragg grating are modeled, from which the parameters of the laser with the highest emission power are determined. For a given concentration of ytterbium ions, the length of the active fiber and the value of the reflection coefficient of the Bragg grating at the output of the resonator, which provide the maximum output power of the laser radiation, have been obtained. The comparison of the results of laser power modeling with experiments has shown that the discrepancy does not exceed 10% and the modeling can be used to select the laser parameters. The developed model is universal and suitable for describing the radiation of fiber lasers with resonators on Bragg gratings and active singlemode fibers doped with other rare earth elements.