Q-switched erbium-doped fiber laser employing gold thin film saturable absorber

Abstract

Abstract This research demonstrates an erbium-doped fiber laser (EDFL) which was passively Q-switched by gold thin film saturable absorber (SA). A very simple technique was used to fabricate the SA, in which the gold was directly deposited on the fiber end face through DC magnetron sputtering at 120 mA of sputtering current. The SA was then inserted into the single ring cavity and achieved Q-switching at a threshold pump power of 38.8 mW. By gradually increasing the pump power from 38.8 mW to 119.3 mW, the repetition rate increases from 11.34 kHz to 21.72 kHz. Meanwhile, the pulse duration decreases from 13.91 us to 7.44 us. The maximum achievable pulse energy was 13.28 nJ. This research further expands the application of gold thin film S A to the field of Q-switched pulsed fiber laser.