Passively Q-switched Erbium doped fiber laser by incorporating a segment of Thulium doped fiber saturable absorber

We propose a segment of 11 cm long Thulium-doped fiber (TDF) as a passive saturable absorber (SA) in generating a stable Q-switched Erbium-doped fiber laser (EDFL). The obtained pulsed laser has a central wavelength of 1560 nm and emerges stably within a repetition rate range of 54.1-106.7 kHz over a pump power range of 35-136 mW. At the maximum pump power of 136 mW, the EDFL produces a maximum output power of 14.3 mW, a maximum pulse energy of 134.7 nJ and a maximum peak power of 41 mW as well as the narrowest pulse width of 3.28 µs. The fundamental frequency of the pulsed laser has a signal to noise ratio (SNR) of approximately 63 dB. The proposed laser would have a good prospect for material processing and medicine.