SDH/SONET Multi-rate SFP Module with Gain Selectable Transimpedance Amplifier and Extinction Ratio Control Circuit

We report a SDH/SONET multi-rate SFP module with a gain selectable transimpedance amplifier (TIA) and a dual-loop APC based on top and bottom level hold. With compliance to SDH (STM-1/4/16) and SONET (OC-3/12/48) specifications even without an additional cost requirement, multi-bit rate operation with higher received sensitivity, fully dual-loop APC operation up to 3 Gbit/s and dynamically rate selecting operation are firstly demonstrated.