Title:Ultrafast, high-power, broad-band lasers enabled by nanotubes and graphene

Speaker: Dr. Zhipei SUN (Engineering Department, University of Cambridge, UK)

Time:At 9:00AM, April 10, 2012

Venue:Academic Salon Room, IOS, CAS

Abstract: Ultrafast lasers play a key role in a variety of devices, from basic research to materials processing and medicine. Nanotubes and graphene have great potential as saturable absorbers for ultrafast lasers. Here we report ultrafast highly chirped pulses from an erbium doped, nanotube-mode-locked fiber oscillator. We generate 1.6 W average power and 11 kW peak power by seeding a fiber amplifier. We realize a stretched-pulse fiber laser based on a nanotube saturable absorber, with 113 fs pulses, 33.5 nm spectral width and ~0.07% amplitude fluctuation, outperforming current nanotube-based designs. The linear dispersions of the Dirac electrons in graphene enable wideband tunability. We get ~1 ps pulses, tunable between 1525 and 1559 nm, with stable mode-locking, insensitive to environmental perturbations.