Second Harmonic Generation Using an All‐Fiber Q‐Switched Yb‐Doped Fiber Laser and MgO:c‐PPLN

We have experimentally demonstrated an efficient all‐fiber passively Q‐switched Yb‐doped fiber laser with Samarium doped fiber as a saturable absorber. Average output power of 3.4 W at a repetition rate of 250 kHz and a pulse width of 1.1 microseconds was obtained at a pump power of 9.0 W. By using this fiber laser system and an MgO‐doped congruent periodically poled lithium niobate (MgO:c‐PPLN), second harmonic generation (SHG) output at 532 nm was achieved at room temperature. The conversion efficiency is around 4.2% which agrees well with the theoretical simulation.