We demonstrate a Q-switched Ytterbium-doped double-cladding fiber laser based on single-walled carbon nanotubes as saturable absorbers. The pure single-walled carbon nanotubes were directly deposited on the one end of the Ytterbium-doped double-cladding fiber by optically driven deposition method. A linear-cavity was employed and a 1.5m long Ytterbium-doped double-cladding fiber played as the gain fiber. The Ytterbium-doped double-cladding fiber was pumped by a 976-nm fiber coupled diode laser. The maximum output power of 1.3W was obtained at the wavelength of 1070nm. The pulse-repetition rates were tuned from 9.1 KHz to 60 KHz when the pump powers were changed from 1.85W to 10W and the shortest pulse duration was around 600ns.
A passively Single-walled carbon nanotube is a new material as a saturable absorber to obtain a Q-switched laser or a mode-locked laser because of it’s broadband absorption wavelength and cheaper price comparing with SESAM. Here, by using a single-walled carbon nanotube as saturable absorber (SWCNT-SA), a passively Q-switched Nd:YCOB (Nd3+:YCa4O(BO3)3)laser was realized at 1085.3nm pumped by a 808 nm diode laser .The fluorescence spectrum of Nd:YCOB crystal near 1.06 μm. The output power of the Q-switched laser of 175 mW were obtained at the pump power of 9W in a V-type cavity. The range of the repetition rate was from 35 kHz to 62.5 kHz and pulse width was 1.6μs (FWHM) at 62.5 kHz.
The single-walled carbon nanotubes (SWCNT) could be used as saturable absorber in Q-Switched and mode-locked lasers. In this paper, the influence of the concentration and the ultrasound time on the absorption coefficient of the single-walled carbon nanotubes was discussed. The structure and morphology of the single-walled carbon nanotubes were investigated by the atomic force microscope（AFM）and the scanning electron microscopy(SEM). When the single-walled carbon nanotube saturable absorbers (SWCNT-SAs) were used in both the Yb-doped double cladding fiber laser and the solid state lasers, the Q-switched pulses were obtained. And we use the single-walled carbon nanotubes saturable absorber (SWCNTs) in the passively Q-switched Nd:YCOB (Nd3+:(Nd3+:YCa4O(BO3)3) laser, a duration of 1.6μs pulses were obtained at the center wavelength of 1085.3 nm, a 175 mW output power were obtained at the pump power of 9W.