Efficient and compact Q-switched green laser using graphene oxide as saturable absorber

Abstract

A new type of graphene oxide (GO) is successfully prepared using an improved modified Hummers method. The Raman shift, X-ray diffraction (XRD), and scanning electron microscope (SEM) measurement techniques are used to characterize the GO. An efficient and compact Q-switched green laser based on Nd:YVO4/PPLN is demonstrated with a few-layered GO as the saturable absorber. Our experimental results show that such a few-layered GO saturable absorber allows for the generation of a stable Q-switched laser pulse centered at 532.1nm with a 3dB spectral bandwidth of 2.78nm, a repetition rate of 71.4kHz, and a pulse duration of 98ns. The maximum average output power of 536mW is obtained at the absorbed pump power of 5.16W, corresponding to an optical conversion efficiency of 10.3%.