An all fiberized, 1.89-μm Q-switched laser employing carbon nanotube evanescent field interaction

An all-fiber-integrated, Q-switched thulium-doped fiber laser based on carbon nanotube (CNT) evanescent field interaction is experimentally demonstrated. It is shown that a saturable absorber based on a CNT-deposited D-shaped fiber can readily be incorporated into a thulium-doped fiber ring cavity for a passive Q-switching operation at a wavelength of similar to 1.89 mu m. Using the laser scheme stable Q-switched pulses with a temporal width of similar to 7.155 mu s could be obtained at a repetition rate of 14.18 kHz. The temporal stability of the output pulses was also investigated. (C) 2012 by Astro, Ltd.