152 fs nanotube-mode-locked thulium-doped all-fiber laser
Ultrafast fiber lasers with broad bandwidth and short pulse duration have a variety of applications, such as ultrafast time-resolved spectroscopy and supercontinuum generation. We report a simple and compact all-fiber thulium-doped femtosecond laser mode-locked by carbon nanotubes. The oscillator operates in slightly normal cavity dispersion at 0.055 ps(2), and delivers 152 fs pulses with 52.8 nm bandwidth and 0.19 nJ pulse energy. This is the shortest pulse duration and the widest spectral width demonstrated from Tm-doped all-fiber lasers based on 1 or 2 dimensional nanomaterials, underscoring their growing potential as versatile saturable absorber materials. ; We acknowledge funding from the Science and Technology Projects of Shenzhen City (JCYJ20150324140036862, JCYJ20140418095735546), the Natural Science Foundation of Guangdong Province (2015A030310464, 2016A030310049), the Scientific Research Foundation of Shenzhen City (827-000118), the Teknologiateollisuus TT-100, the European Union's Seventh Framework Programme (REA grant agreement No. 631610), the Academy of Finland (No. 284548), Tekes (OPEC) and Aalto University (Finland). TH acknowledges funding from the Royal Academy of Engineering through a research fellowship (Graphlex). ; This is the final version of the article. It first appeared from Nature Publishing Group at http://dx.doi.org/10.1038/srep28885.
