All-fiber pulsed lasers passively mode locked by transferable vertically aligned carbon nanotube film

An all-fiber passive laser mode locking is realized with a vertically aligned single-walled carbon nanotube film that can be transferred onto an arbitrary substrate using only hot water. A D-shaped fiber is employed as the substrate for the evanescent field interaction of propagating light with the nanotubes. The scheme highlights the efficient interaction achieved by the nanotube alignment as well as the dramatically simplified device preparation process. The demonstrated pulsed laser output has 2.9 nm of spectral full width at half-maximum and a 20.8 MHz repetition rate.