2kW narrow linewidth all fiber laser

摘要

Recently, narrow linewidth fiber lasers are wide applied in coherent detection and wavelength beam combining. The influence of fiber grating oscillating longitudinal mode distribution and the amplifier gain fiber characteristics on the output laser spectrum width are explored. The influence of the optical field distribution and the spatial hole burning effect on oscillating longitudinal modes number is analyzed. And the influence of four-wave mixing effect (FWM) in the amplified laser on the spectral width of the output laser is analyzed. The main oscillation power amplification technology of one-stage oscillation and one-stage amplification is used. Finally, the influence of the reflection bandwidth of the resonant cavity, the longitudinal mode number of the main oscillation stage and the length and core diameter of the gain fiber of the amplifier stage on the output laser spectrum width is studied. Spectral width of 0.29nm, power of 2kW and center wavelength of 1064.4nm is realized. The beam quality is M_x~2= 1.2, M_y~2= 1.3.