Ultrafast Mode-Locked Fiber Laser Using a Waveguide-Type Saturable Absorber Based on Single-Walled Carbon Nanotubes

We report a waveguide-type single-walled carbon nanotube saturable absorber (SWCNT-SA) for passive mode-locking of ultrafast lasers. Conventional silica planar lightwave circuit (PLC) waveguides possessing excellent stability and low propagation loss are employed for efficient interaction with SWCNTs. A high-quality SWCNT/polymer composite is coated on the PLC chip under optimized conditions. We then analyze the linear and nonlinear transmission properties of the fabricated waveguide-type SA. As a proof of our concept, a mode-locked fiber laser including our SA was built; it stably delivers 602 fs pulses with an average output power of 8.58 mW at a repetition rate of 11.25 MHz. (c) 2013 The Japan Society of Applied Physics