All-Polarization-Maintaining, Mode-Locked 488 nm Picosecond Laser

In this letter, we report a 488 nm blue picosecond pulse generation by frequency doubling of a homemade 977 nm watt-level picosecond all polarization maintaining mode-locked fiber laser. Based on a SESAM passively mode-locked Yb-doped fiber linear cavity configuration, the 977 nm picosecond seed laser shows a 977.84 nm central wavelength, 0.13 nm spectral width, 12.94 ps pulse duration, 76.09 MHz repetition rate, and 5.12 mW average power, respectively. The average power is further scaled up to 2.06 W by adopting an all-fiber MOPA structure, and the pulse duration and spectral width are slightly broadened to 16.84 ps and 0.24 nm, respectively. Furthermore, a 147.40 mW blue picosecond pulsed laser with a 488.92 nm central wavelength and 0.17 nm linewidth is successfully achieved by frequency doubling in a MgO2:PPLN crystal. Such compact, high-power, and narrow-linewidth picosecond blue laser is a promising candidate for high-resolution imaging, underwater detection and material processing, etc.