Converting Electrical Signals to Optical Signals: The optical transceiver receives electrical signals from network equipment, such as a router or switch. This write-up offers a detailed description of SFP optical transceivers, including their types, how they. Although it is physically small, the optical transceiver plays a critical role in connecting switches, routers, and servers across modern networks. Without it, the high-speed fiber connections that power today's data centers simply would not exist. This article explains what an optical transceiver.