Use of the acousto-optic tunable filter for optical spectrum analysis and EDFA power equalization in WDM systems

Summary form only given. In order to use a cascade of erbium-doped fiber amplifiers (EDFAs) in a wavelength-division multiplexing (WDM) system, the power output of the signal channels must be equalized. We demonstrate a system for power equalization that consists of two single-stage acousto-optical tunable filters (AOTFs). To our knowledge, this is the first use of the AOTF as an optical spectrum analyzer in a WDM system.