Plasmonic Ag nanoparticles embedded in lithium tantalate crystal for ultrafast laser generation

摘要

We report the Ag nanoparticles (NPs) embedded in LiTaO3 (AgNP:LT) by direct Ag+ ion implantation. Transmission electron microscope imaging indicates that the embedded Ag NPs have an average diameter of 3.65 nm. The linear optical absorption spectrum of AgNP:LT peaking at 477 nm is observed owing to the typical effect of localized surface plasmon resonance. Z-scan investigation shows ultrafast saturable absorption of AgNP:LT at the near infrared 1 mu m wavelength, which enables AgNP:LT to be a new saturable absorber (SA) for the generation of 1 mu m Q-switched mode-locked pulsed laser with pulse duration of 35 ps and repetition rate of 8.74 GHz. This work not only opens a new way to tailor the nonlinearity of LiTaO3 by embedding Ag+ NPs, but also develops AgNP:LT as a new SA for ultrafast laser generation.