L -band ultrafast fiber laser mode locked by carbon nanotubes

Abstract

We fabricate a nanotube-polyvinyl alcohol saturable absorber with a broad absorption at $1.6\mu \text{m}$ . We demonstrate a pulsed fiber laser working in the telecommunication $L$ band by using this composite as a mode locker. This gives $\sim 498\pm 16\text{fs}$ pulses at 1601 nm with a 26.7 MHz repetition rate.