Photodeposition of SWCNTs onto the optical fiber end to assemble a Q-switched Er3+-doped fiber laser

An experimental study on optical pulses generation using single-wall carbon nanotubes as a saturable absorbers in an Er3+-doped fiber laser is reported. The saturable absorber was made by the photodeposition technique to place single-wall carbon nanotubes onto an optical fiber end. This technique consists of light laser provided by an Er3+-doped fiber amplifier and single-wall carbon nanotubes suspended in an aqueous solution. Using a fiber splice tube, the optical fiber with the single-wall carbon nanotubes is placed in the Er3+-doped fiber laser cavity. The nonlinear absorption of the saturable absorber was characterized by P-scan technique using a high gain pulsed Er3+-doped fiber amplifier. The results demonstrated that is possible to obtain optical pulses generation by using the single-wall carbon nanotubes as saturable absorber. The pulses duration are from 8.5 to 18 μs with a repetition rate around of 16-19.5 kHz. The nonlinear absorption of the single-wall carbon nanotubes photodeposited onto an optical fiber end is approximately −5.25×10−6m/W.