A fiber optic transceiver (also called an optical transceiver) is a compact module that both transmits and receives data signals through optical fibers. This assembly comprises a light source, such as a laser diode or a semiconductor light-emitting diode (LED), an optical interface, a monitoring photodiode, a housing made of either metal or plastic, and an electrical interface. There are no specific requirements for this document. This includes Doppler. Optical modules operate by converting electrical signals from network devices into light signals that travel through fiber optic cables.