We demonstrate a mode locked fiber laser based on single wall carbon nanotubes. The mode locking is achieved by the evanescent field interaction of the propagating light with a single wall carbon nanotubes saturable absorber in a microfiber. The pulse width is 114fs. The maximum average output power is 21mW. The center of the wavelength is 1556nm with 26nm spectral width. The repetition rate is 111.6MHz. Keywords: Ultrafast lasers; Mode locked lasers; carbon nanotubes.
A model of 1.2μm Phosphorus doped Raman fiber laser is discussed. It is pumped by a 1.035μm high power
Yb-doped dual-cladding fiber laser. The coupled equations for forward and backward stokes waves are set up. An
approximate solution for the first –order Stocks laser is obtained by using ‘fsolve’ function in MATLAB which is simply
for writing and calculates fast. The relationships between energy conversion efficiency and the length of P-doped fiber,
the reflectivity of the output FLM are discussed respectively. And the laser system is optimized.
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+:(Nd<sup>3+</sup>:YCa<sub>4</sub>O(BO<sub>3</sub>)<sub>3</sub>) 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.
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 (Nd<sup>3+</sup>:YCa<sub>4</sub>O(BO<sub>3</sub>)<sub>3</sub>)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.
In the nonlinear polarization rotation (NPR) mode locking fiber laser, the electric fields of different intensity of pluses
will have different nonlinear phase shifts because of self phase modulation (SPM) and cross-phase modulation (XPM)
effects. In this paper we analysis the SPM and XPM effect on the characteristics of pulses in fiber which were
influenced when we adjustment the wave plates in the NPR fiber lasers. At the same time, we discussed the pulses
waveform's influence caused by the strength of the SPM and XPM in fibers.
With 4th-order Runge-kutta method and relaxation method, we obtain the power distribution of pump light and signal
light along fiber by solving the steady-state rate equations in ytterbium-doped double-cladding fiber amplifier. The
relationships between the output power and the fiber length are discussed with different pump power and different doped
concentrations of the fiber. The change of the output power versus the pump power is calculated. The power distribution
along fiber and the relationship between output power and input power are analyzed when the signal is injected from z=L
and z=0 respectively.