We demonstrate an all-fiber Q-switched cylindrical vector laser based on a black phosphorus saturable absorber and a transverse mode converter. The saturable absorber is prepared by incorporating the polyvinyl alcohol with anti-oxidized black phosphorus nanosheets exfoliated in aqueous poly dimethyldiallyl ammonium chloride solutions. The mode converter is composed of tapered two-mode fiber and single-mode fiber, and it can excite switchable azimuthally and radially polarized beams by modulating the input polarization. By enhancing the pump power from 64.68 mW to 174.82 mW, the repetition rate of Q-switched azimuthally/radially polarized laser enlarges from 16.72/19.25 kHz to 30.71/37.82 kHz.
He Zhiwen, Zheng Yang, Liu Hongyan, Li Mingkun, Lu Hua, Zhang Heze, Feng Qingliang, Mao Dong. Passively Q-switched cylindrical vector laser based on a black phosphorus saturable absorber[J]. Chinese Optics Letters, 2019, 17(2): .
