title: Can silicon carbide serve as a saturable absorber for passive mode-locked fiber lasers?
abstract: The study presents a novel demonstration of a passively mode-locked erbium-doped fiber laser (EDFL) that is based on a silicon carbide (SixC1-x) saturable absorber. When the C/Si composition ratio is increased to 1.83, the SixC1-x film transforms from two-photon absorption to nonlinear saturable absorption, and the corresponding value reaches -3.9 × 10(-6) cm/W. The Si-rich SixC1-x film cannot mode lock the EDFL because it induced high intracavity loss through two-photon absorption. Even when a stoichiometric SiC is used, the EDFL is mode locked, similar to an EDFL operating under weak nonlinear-polarization-rotation condition. A C-rich SixC1-x film containing sp(2)-orbital C-C bonds with a linear absorbance of 0.172 and nonlinear absorbance of 0.04 at a 181 MW/cm(2) saturation intensity demonstrates nonlinear transmittance. The C-rich SixC1-x saturable absorber successfully generates a short mode-locked EDFL pulse of 470 fs. The fluctuation of the pulse-train envelope dropps considerably from 11.6% to 0.8% when a strong saturable-absorption-induced self-amplitude modulation process occurs in the C-rich SixC1-x film.
authors.affiliation: Graduate Institute of Photonics and Optoelectronics, Department of Electrical Engineering, National Taiwan University (NTU), No. 1, Sec. 4, Roosevelt Road, Taipei 106, Taiwan R.O.C.
authors.forename: Chih-Hsien
authors.initials: CH
authors.lastname: Cheng
authors.affiliation: Graduate Institute of Photonics and Optoelectronics, Department of Electrical Engineering, National Taiwan University (NTU), No. 1, Sec. 4, Roosevelt Road, Taipei 106, Taiwan R.O.C.
authors.forename: Yung-Hsiang
authors.initials: YH
authors.lastname: Lin
authors.affiliation: Graduate Institute of Photonics and Optoelectronics, Department of Electrical Engineering, National Taiwan University (NTU), No. 1, Sec. 4, Roosevelt Road, Taipei 106, Taiwan R.O.C.
authors.forename: Ting-Hui
authors.initials: TH
authors.lastname: Chen
authors.affiliation: Graduate Institute of Photonics and Optoelectronics, Department of Electrical Engineering, National Taiwan University (NTU), No. 1, Sec. 4, Roosevelt Road, Taipei 106, Taiwan R.O.C.
authors.forename: Hsiang-Yu
authors.initials: HY
authors.lastname: Chen
authors.affiliation: Graduate Institute of Photonics and Optoelectronics, Department of Electrical Engineering, National Taiwan University (NTU), No. 1, Sec. 4, Roosevelt Road, Taipei 106, Taiwan R.O.C.
authors.forename: Yu-Chieh
authors.initials: YC
authors.lastname: Chi
authors.forename: Chao-Kuei
authors.initials: CK
authors.lastname: Lee
authors.affiliation: Department of Photonics, National Sun Yat-sen University, No. 70, Lien-Hai Rd, Kaohsiung 804, Taiwan.
authors.forename: Chao-Kuei
authors.initials: CK
authors.lastname: Leeb
authors.forename: Chih-I
authors.initials: CI
authors.lastname: Wu
authors.affiliation: Graduate Institute of Photonics and Optoelectronics, Department of Electrical Engineering, National Taiwan University (NTU), No. 1, Sec. 4, Roosevelt Road, Taipei 106, Taiwan R.O.C.
authors.forename: Chih-I
authors.initials: CI
authors.lastname: Wua
authors.affiliation: Graduate Institute of Photonics and Optoelectronics, Department of Electrical Engineering, National Taiwan University (NTU), No. 1, Sec. 4, Roosevelt Road, Taipei 106, Taiwan R.O.C.
authors.forename: Gong-Ru
authors.initials: GR
authors.lastname: Lin