▎ 摘　　要

A stable passive Q-switched Ytterbium doped fiber laser (YDFL) is demonstrated by using a graphene oxide (GO) embedded in polyethylene oxide (PEO) film a as saturable absorber (SA). The SA was fabricated by mixing a dispersed GO composite with PEO solution thoroughly through an ultra-sonification process. The mixture solution is dried to form a film, which is then put in between two FC/PC fiber ferrule so that it can be easily incorporated in YDFL's ring cavity. A stable ()switched laser operating at wavelength of 1040.7 nm was self-started at pump power of 93 mW with the SA. At pump power of 111 mW, the YDFL generates an optical pulse train with a repetition rate of 28.75 kHz and pulse width of 9.1 mu s. The maximum pulse energy of 20.6 nJ was obtained at pump power of 99 mW while the maximum output power of 0.24 mW was obtained at pump power of 128 mW.