Active–passive Q-switched fiber laser based on graphene microfiber
We report an active–passive Q-switched laser based on graphene-covered microfiber modulator. The graphene-covered microfiber not only serves as a passive saturable absorber in a single laser cavity, but also can be used as an all-optical modulation device to synchronize two pulses generated from different wavelengths. The laser can not only actively change the output frequency of the Q-switched pulse to achieve the repetition frequency reduction, but also compress the pulse and increase the peak power of the output pulse. We successfully achieve the output of the active–passive Q-switched pulse using this fiber laser with a repetition rate from 41.1 kHz to 50.5 kHz. The fiber laser has potential applications in simultaneous output of multi-wavelength pulse.
This work was supported by the International Cooperative Program (Grant No. 2014DFR10780), the National Science Foundation of China (No. 61505162), the Foundation of the Education Committee of Shaanxi Province (No. 14JK1756), the Natural Science Basic Research Plan in Shaanxi Province of China (No. 2016JQ6059), the Science and Technology innovation and Entrepreneurship double tutor project of Shaanxi province (2018JM1059).