Polarization Maintaining, Nanotube-Based Mode-Locked Lasing From Figure of Eight Fiber Laser

We propose and demonstrate an all-fiber, polarization maintaining (PM) ultrafast fiber laser using a hybrid mode-locking mechanism consisting of a nonlinear amplifying loop mirror and carbon nanotube saturable absorber (CNT-SA). By incorporating the CNT-SA, the threshold for mode-locked operation is reduced by approximately a factor of 3, from 330 to 120 mW. Moreover, the all-PM fiber design provides excellent stability and turnkey operation.