A Q-Switched Erbium-Doped Fiber Laser with a Carbon Nanotube Based Saturable Absorber

We demonstrate a simple,compact and low cost Q-switched erbium-doped fiber laser(EDFL)using single-wall carbon nanotubes(CNTs)as a saturable absorber for possible applications in metrology,sensing,and medical diagnostics.The EDFL operates at around 1560 nm with repetition rates of 16.1 kHz and 6.4 kHz with saturable absorbers SA1 and SA2 at a pump power of 120 mW.The absorbers are constructed by optically driven deposition and normal deposition techniques.It is observed that the optical deposition method produces a Q-switched EDFL with a lower threshold of 70 mW and better Q-switching performance compared to that of the normal deposition method.The EDFL also has pulse energy of 90.3 nJ and pulse width of 11.6μs at 120 mW pump power.

Performance Comparison of Mode-Locked Erbium-Doped Fiber Laser with Nonlinear Polarization Rotation and Saturable Absorber Approaches

A mode-locked erbium-doped fiber laser (EDFL) is demonstrated using a highly concentrated erbium-doped fiber (EDF) as the gain medium in a ring configuration with and without a saturable absorber (SA).Without the SA,the proposed laser generates soliton pulses with a repetition rate of 12 MHz,pulse width of 1.11 ps and energy pulse of 1.6pJ.By incorporating SA in the ring cavity,the optical output of the laser changes from soliton to stretched pulses due to the slight change in the group velocity dispersion.With the SA,a cleaner pulse is obtained with a repetition rate of 11.3 MHz,a pulse width of 0.58ps and a pulse energy of 2.3pJ.