Wideband-tuneable, nanotube mode-locked, fibre laser.
Ultrashort-pulse lasers with spectral tuning capability have widespread applications in fields such as spectroscopy, biomedical research and telecommunications. Mode-locked fibre lasers are convenient and powerful sources of ultrashort pulses, and the inclusion of a broadband saturable absorber as a passive optical switch inside the laser cavity may offer tuneability over a range of wavelengths. Semiconductor saturable absorber mirrors are widely used in fibre lasers, but their operating range is typically limited to a few tens of nanometres, and their fabrication can be challenging in the 1.3-1.5 microm wavelength region used for optical communications. Single-walled carbon nanotubes are excellent saturable absorbers because of their subpicosecond recovery time, low saturation intensity, polarization insensitivity, and mechanical and environmental robustness. Here, we engineer a nanotube-polycarbonate film with a wide bandwidth (>300 nm) around 1.55 microm, and then use it to demonstrate a 2.4 ps Er(3+)-doped fibre laser that is tuneable from 1,518 to 1,558 nm. In principle, different diameters and chiralities of nanotubes could be combined to enable compact, mode-locked fibre lasers that are tuneable over a much broader range of wavelengths than other systems.
Wang
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F
Department of Engineering, University of Cambridge, 9 JJ Thomson Avenue, Cambridge, CB3 0FA, UK.
Rozhin
A G
AG
Scardaci
V
V
Sun
Z
Z
Hennrich
F
F
White
I H
IH
Milne
W I
WI
Ferrari
A C
AC
D004867:Equipment Design; D005336:Fiber Optic Technology / Q000295:instrumentation*; D007834:Lasers; D036103:Nanotechnology / Q000295:instrumentation; D037742:Nanotubes, Carbon; D012666:Semiconductors
D037742:Nanotubes, Carbon