title: Concentration effect of carbon nanotube based saturable absorber on stabilizing and shortening mode-locked pulse.
abstract: We comprehensively investigated the concentration effect of dispersed single-walled carbon nanotubes (SWCNTs) in polymer films for being a saturable absorber (SA) to stabilize the mode locking performance of the erbium-doped fiber laser (EDFL) pulse through the diagnosis of its nonlinear properties of SA. The measured modulation depth was from 1 to 4.5% as the thickness increased 18 to 265 microm. The full-width half-maximum (FWHM) of the stable mode-locked EDFL (MLEDFL) pulse decreased from 3.43 to 2.02 ps as the concentrations of SWCNTs SA increased 0.125 to 0.5 wt%. At constant concentration of 0.125 wt%, the similar pulse shortening effect of the MLEDFL was also observed when the FWHM decreased from 3.43 to 1.85 ps as the thickness of SWCNTs SA increased 8 to 100 microm. With an erbium-doped fiber length of 80 cm, the shortest pulse width of 1.85 ps were achieved at 1.56 microm with a repetition rate of 11.1 MHz and 0.2 mW of the output power under an output coupling ratio of 5%. An in-depth study on the stable mode-locked pulse formation employing SWCNTs SA, it is possible to fabricate the SWCNT films for use in high performance MLEDFL and utilization of many other low-cost nanodevices.
authors.affiliation: Department of Photonics, National Sun Yat-sen University, Kaohsiung, Taiwan.
authors.forename: Jin-Chen
authors.initials: JC
authors.lastname: Chiu
authors.forename: Yi-Fen
authors.initials: YF
authors.lastname: Lan
authors.forename: Chia-Ming
authors.initials: CM
authors.lastname: Chang
authors.forename: Xi-Zong
authors.initials: XZ
authors.lastname: Chen
authors.forename: Chao-Yung
authors.initials: CY
authors.lastname: Yeh
authors.forename: Chao-Kuei
authors.initials: CK
authors.lastname: Lee
authors.forename: Gong-Ru
authors.initials: GR
authors.lastname: Lin
authors.forename: Jiang-Jen
authors.initials: JJ
authors.lastname: Lin
authors.forename: Wood-Hi
authors.initials: WH
authors.lastname: Cheng
mesh_terms: D004867:Equipment Design; D019544:Equipment Failure Analysis; D053844:Lasers, Solid-State; D008027:Light; D037742:Nanotubes, Carbon / Q000737:chemistry* / Q000648:ultrastructure*; D012542:Scattering, Radiation; D012815:Signal Processing, Computer-Assisted / Q000295:instrumentation*
chemical_list: D037742:Nanotubes, Carbon