Multiple wavelength switching fiber laser with fiber structure, smaller coupled losses, small size, ease of integration and many other advantages, is wave division multiplexing WDM and dense wavelength division multiplexing DWDM important light Its performance directly determines the quality of optical communication systems, the importance of increasing, there is an urgent need to further study, improve its performance to be an inevitable This article details the study of dual - wavelength fiber laser based on AWG, a sketch of arrayed waveguide grating ( AWG ) works, taken together, this paper is divided into the following sections : Elaborate on the rationale and basic structure of a fiber laser, and describes several wavelength switched erbium - doped fiber On experimental needs in optical instruments are described in detail, including the EDFA, optical attenuator, optical Coupler, optical wave division multiplexing, optical isolator, light switches, filters and phase modulation, intensity modulator and so Conducted an in-depth study on multi-wavelength fiber lasers, and elaborated on several stable multi-wavelength fiber laser technology at room