Research on picosecond pulsed all-fiber Yb-doped laser with 1.2-GHz repetition rate

We demonstrate an all-fiber picosecond laser with a repetition rate of 1.2 GHz. The seed source is a passively modelocked Yb-doped fiber laser. The pulse width of the seed laser is 4.2 ps with a repetition rate of 19.2 MHz, and the seed exhibits a spectral bandwidth of 3.6 nm at the center wavelength of 1064.1 nm. Due to the length of the cavity, it is difficult to increase the repetition rate of the fiber laser. To solve the above problem, we provide a high-repetition-rate pulsed laser modulator comprising: five 2 × 2 type, splitting ratio 50:50 couplers, two 1 × 2 type, splitting ratio 50:50 couplers, to increase the repetition rate of the seed laser to 1.2 GHz. Meanwhile, the novel combination of the devices can realize a low-loss mutual coupling of laser pulses.