Au triangles array as saturable absorber for a 1.5 $\mu \mathbf{m}$ passively mode-locked erbium-doped fiber laser

In this paper, we report a passive mode-locking erbium-doped fiber laser (EDFL) that using Au triangles array (Au TA) as saturable absorber fabricated successfully on the fiber tips (OFTs) by nanosphere lithography technology. By using the nanosphere with diameter of 1300 nm, we obtain the localized surface plasmon resonance (LSPR) supported by the Au TA near the C-band (1614 nm). The stable passively mode-locked laser based on Au TA is obtained with a repetition rate of 2.08 MHz and a pulse period of 480 ns for a pump power of 704 mW at 1558 nm. These result may provide a reference in fields of nonlinear optics, micro nano sensing, medical imaging.