Optical transceivers, also known as fiber optic transceivers or simply "transceivers," are electronic devices used in fiber optic communication systems to transmit and receive data over optical fibers. They serve as the interface between the electronic devices, such as switches, routers, servers, and network equipment, and the optical fiber medium.

The optical transceiver integrates both a transmitter and a receiver into a single compact package. It converts electrical signals into optical signals for transmission over the optical fiber and then back into electrical signals for data reception. The transmitter part of the transceiver uses a laser or light-emitting diode (LED) to convert electrical signals into light pulses, while the receiver part uses a photodiode or a photodetector to convert incoming light pulses back into electrical signals.

Optical transceivers come in various form factors and with different specifications to support various fiber optic standards and data transmission rates. Some common form factors include Small Form-Factor Pluggable SFP, SFP+, SFP28, QSFP+, QSFP28, and QSFP-DD optics.

The QSFP-DD modules can support 400Gbps while QSFP+/QSFP28/QSFP56 can only reach 40Gbps/100Gbps/200Gbps respectively.

Each form factor is designed to support specific data rates, ranging from 1Gbps (Gigabit per second) to 400Gbps and beyond, depending on the transceiver's capabilities and the communication standard it adheres to, such as Ethernet, Fiber Channel, InfiniBand, or SONET/SDH.

Optical transceivers play a vital role in modern telecommunication networks, data centers, and high-performance computing environments. They provide the essential means for transmitting large amounts of data over long distances with minimal signal loss and electromagnetic interference, ensuring efficient and reliable data communication over fiber optic links.