Preparation of ultrathin graphitic carbon nitride nanosheet and its application to a tunable multi-wavelength mode-locked fiber laser

• Published in: Optical materials Vol. 86; pp. 382 - 386
• Main Authors: Lou, Yajun, Shi, Yihuan, Liu, Shunxiang, He, Junshan, Li, Yonghui, Tao, Lili, Zeng, Longhui, Long, Hui, Wen, Qiao, Li, Jingbo
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.12.2018
• Subjects: Graphitic carbon nitride; Mode-locked fiber laser; Saturable absorber; Tunable multi-wavelength; Mode-locked fiber laser; Saturable absorber; Tunable multi-wavelength; Graphitic carbon nitride
• ISSN: 0925-3467; 1873-1252
• DOI: 10.1016/j.optmat.2018.10.037

Tunable multi-wavelength mode-locked ytterbium-doped fiber laser is realized by using ultrathin graphitic carbon nitride (g-C3N4) nanosheets as saturable absorber. g-C3N4 nanosheets with an average thickness of 3.5 nm are obtained through liquid-phase ultrasonic exfoliation of g-C3N4 powder prepared by high temperature sintering. Passively mode-locked ytterbium-doped fiber laser was obtained by using the g-C3N4 nanosheets coated D-shaped fiber as saturable absorber. It is interesting that tunable dual-, triple- and quadruple-wavelength mode-locked lasers were obtained by adjusting the pump power and polarization controller. And the maximum average output power of the mode-locked laser can reach 10.32 mW. The pulse width of the quadruple-wavelength mode-locked laser is 1.9 ns, with a working repetition of 11.2 MHz. To our best knowledge, this is the first time reporting this tunable multi-wavelength mode-locking phenomenon based on g-C3N4. •Ultrathin g-C3N4 nanosheets (~3.5 nm thick) were prepared.•Stable mode-locked laser was realized based on the prepared ultrathin g-C3N4 nanosheets.•Interesting tunable dual- triple- and quadruple-wavelength mode-locked lasers based on g-C3N4 were first reported.