We demonstrate, for the first time to the best of our knowledge, an all fiber actively Q-switched Yb-doped laser generating cylindrical vector beams (CVBs) based on a fused mode coupler as the transverse mode converter and selector, and an acousto-optic modulator as the active Q-switching element. The radially and azimuthally polarized beams can be switched by adjusting the polarization controllers in the fiber ring cavity, with high mode purities measured to be >93.5%. Stable ns pulses with repetition rate from 30 Hz to 27 kHz were achieved near the wavelength of 1.0 μm. The actively Q-switched CVB with a pulse width of 68 ns, a pulse energy of 3.46 μJ and a peak power of 50.1 W has been obtained when the repetition rate is 30 Hz and the pump power is 150 mW. This flexible Q-switched fiber laser with pulsed CVB output could find potential applications in the fields of materials processing, nonlinear optics and so on.
Wan, H., Wang, J., Shen, Z., Chen, Y., Zhang, Z., Wang, P., & Zhang, L. (2018). All fiber actively Q-switched Yb-doped laser with radially/azimuthally polarized beam generation. Laser Physics Letters, 15(9), . https://doi.org/10.1088/1612-202X/aacb4b