Study Of The Wide Tunable Range Er³⁺-Doped Fiber Laser Based Acousto-Optical Tunable Filter

Wavelength-Division-Multiplexing (WDM) is an effective approach which increases extremely capacity of fiber communication system, and which is an international progress direction of fiber communication technology. Tunable laser and wavelength filter are two kinds of key devices in WDM fiber communication system, and tunable laser is used in the fields of coherent communication, fiber sensor and spectrum analysis as well.Tunable erbium-doped fiber laser using an integrated optics acousto-optical tunable wavelength filter (AOTF) was studied, which has many merits such as very wide tunable range, narrow linewidth, quick tuning speed, easy and reliable tuning and right matching fiber. So it is just fit for WDM fiber communication.The research is composed of three main parts: 1. The study of the output characteristics of the AOTF; According to the transfer function of the AOTF which is presented from the theory of coupling mode, a figure of output characteristics of the AOTF are attained by Matlab program. Then its output characteristics are discussed both in theory and experiment; 2. The study of the output characteristics of acousto-optical tunable erbium-doped fiber ring laser; its output characteristics are discussed both in theory and experiment, and the differences are also discussed between theory and experiment; 3. The study of the tunable range of acousto-optical tunable erbium-doped fiber ring laser; According to the rate equation and transfers equations applicable to the erbium-doped fiber amplifier, the main factor confined the tunable range of acousto-optical tunable erbium-doped fiber ring laser which is considered as the amplificatory range of erbium-doped fiber amplifier was obtained. The experimental on the tunable range of acousto-optical tunable erbium-doped fiber ring laser was shown that the tunable range is consistent with theoretical calculate.