title: Highly efficient femtosecond pulse stretching by tailoring cavity dispersion in erbium fiber lasers with an intracavity short-pass edge filter.
abstract: We demonstrate highly efficient pulse stretching in Er(3+)-doped femtosecond mode-locked fiber lasers by tailoring cavity dispersion using an intracavity short-pass edge filter. The cavity dispersion is preset at around zero to obtain the shortest pulsewidth. When the cutoff wavelength of the short-pass edge filter is thermo-optically tuned to overlap the constituting spectral components of mode-locked pulses, large negative waveguide dispersion is introduced by the steep cutoff slope and the total cavity dispersion is moved to normal dispersion regime to broaden the pulsewidth. The time-bandwidth product of the mode-locked pulse increases with the decreasing temperature at the optical liquid surrounding the short-pass edge filter. Pulse stretch ratio of 3.53 (623.8 fs/176.8 fs) can be efficiently achieved under a temperature variation of 4 °C.
authors.affiliation: Department of Electro-Optical Engineering, National United University, Miaoli, 360, Taiwan. nkchen@nuu.edu.tw
authors.forename: Nan-Kuang
authors.initials: NK
authors.lastname: Chen
authors.forename: Feng-Zhou
authors.initials: FZ
authors.lastname: Liu
authors.forename: Hsiu-Po
authors.initials: HP
authors.lastname: Chuang
authors.forename: Yinchieh
authors.initials: Y
authors.lastname: Lai
authors.forename: Shang-Da
authors.initials: SD
authors.lastname: Yang
authors.forename: Jim-Wein
authors.initials: JW
authors.lastname: Lin
authors.forename: Shien-Kuei
authors.initials: SK
authors.lastname: Liaw
authors.forename: Yu-Chung
authors.initials: YC
authors.lastname: Chang
authors.forename: Chen-Bin
authors.initials: CB
authors.lastname: Huang
authors.forename: Sien
authors.initials: S
authors.lastname: Chi