Q-switched and tunable wavelength fiber laser utilizing nickel oxide saturable absorber and sagnac loop mirror filter

• Published in: Infrared physics & technology 2020-09, Vol.109, p.103433, Article 103433
• Main Authors: Rizman, Z.I., Zulkipli, N.F., Arof, H., Yasin, M., Harun, S.W.
• Format: Article
• Language: English
• Subjects: Erbium-doped fiber lasers; Q-switching; Sagnac loop mirror; Tunable laser
• ISSN: 1350-4495; 1879-0275
• DOI: 10.1016/j.infrared.2020.103433

•Tunable Q-switched fiber laser with Sagnac Loop and Nickel Oxide (NiO) Saturable Absorber.•The NiO film was integrated into a figure-of-eight resonator.•The laser operation can be tuned from 1551.9 nm to 1544.1 nm with the increase of temperature from 30 °C to 70 °C.•The pulse operated at repetition rate of 45.7 kHz with pulse energy of 13.1 nJ at 161 mW pump power. We demonstrate a Q-switched Erbium-doped fiber laser (EDFL) with a tunable output wavelength using Nickel oxide (NiO) saturable absorber (SA) in conjunction with a Sagnac loop mirror (SLM) filter. The proposed SA was prepared by embedding NiO nanoparticles obtained bysimplistic sonochemical reaction into polyethylene oxide (PEO). The NiO PEO film was integrated into a figure-of-eight resonator configured with a SLM to generate Q-switched pulses with a tunable output wavelength. As the SLM temperature was increased from 30 °C to 70 °C, the laser operation can be tuned from 1551.9 nm to 1544.1 nm. At 1551.9 nm operation, the repetition rate rose from 36.2 kHz to 40.3 kHz and the pulse duration reduced from 10.00 to 9.32 μs when the pump power rose from 131.5 to 161.0 mW. At the highest pump power of 161.0 mW, the maximum output power and pulse energy were obtained at 0.67 mW and 16.6 nJ. For Q-switched operation at 1544.1 nm, the produced Q-switched pulse exhibited a pulse duration of 8.88 μs, the repetition rate of 45.7 kHz, the highest output power of 0.60 mW and pulse energy of 13.1 nJ at the maximum pump power of 161.0 mW.