Ultrafast soliton mode-locked fiber laser at 1560 nm based on Znq₂as a saturable absorber

A mode-locked fiber laser was developed by using bis(8-hydroxyquinoline) zinc (Znq2) as a saturable absorber (SA). Znq2 is an organic metal chelate with several advantages such as good saturable absorption, relatively high damage threshold, and an easy, low-cost, and simple fabrication process. The developed SA based on Znq2 has a linear absorption (at 1560 nm), modulation depth, and saturation intensity of 1.2 dB, 16.6 %, and 95 MW/cm2, respectively. The laser cavity produced a very stable soliton mode-locking operation at 1560.6 nm with pulse duration, repetition rate, and SNR of 1.46 ps, 3.5 MHz, and 60.6 dB, respectively. This work is the first, to the best of our knowledge, to report Znq2 as a mode locker.