Self-balanced Q- and gain-switched erbium all-fiber laser

We demonstrate a 980-nm CW-pumped fully passive pulsed all-Er³ all-fiber laser, self-balancing between being Q- and gain-switched at S and L bands. The laser was passively Q-switched at 1510 nm with the saturable absorber in an intra-cavity gain-switched at 1570 nm. The time spacing between the Q- and gain-switched pulse peaks was steadily 0.92 or 2.75 s depending on the absorber lengths. Sequential 1510-nm pulsing with a pulse energy of 3.8 J and a pulse width of 280 ns at a repetition rate of 1.7 kHz was achieved with a pump power of 175 mW.