A fiber optic transceiver (also called an optical transceiver) is a compact module that both transmits and receives data signals through optical fibers. Today, when we talk about optical modules, we usually mean. After transmission through the optical fiber, the receiving interface converts the optical signals into electrical signals using a photodetector diode and outputs electrical signals of the corresponding bit rate after pre-amplification. The appearance and structure of Optical Module The types of. The optical module serves as a crucial component in optical fiber communication systems, operating at the physical layer, which is the lowest layer in the OSI model.