The optical transceiver module is a network interconnection device that realizes photoelectric signal conversion, and the repeater is a network interconnection device that realizes the regeneration, amplification and wavelength conversion of optical signals. conversion, but the functions and applications of the two are very different, and they are not interchangeable.

Optical Module VS Transponder
As a communication device that transmits and receives optical signals, optical modules are often used in optical fiber communication systems such as data centers, enterprise networks, cloud computing, and FTTX. Usually, optical modules support hot swap and can be used in module slots of network equipment such as network switches and servers. There are many types of optical modules on the market, such as 1G SFP, 10G SFP+, 25G SFP28, 40G QSFP+, 100G QSFP28, 400G QSFP-DD optical modules, etc. They are usually used with different types of fiber jumpers or network cables to achieve different distances. Network transmission, the transmission distance ranges from 30 meters to 160 kilometers. In addition, BiDi optical modules can transmit and receive signals through a single optical fiber, which effectively simplifies wiring, increases network capacity, and reduces wiring infrastructure costs. Similarly, WDM series optical modules (ie CWDM and DWDM optical modules) can also multiplex signals of different wavelengths onto the same optical fiber for transmission, which is common in WDM/OTN networks.

A repeater, also known as an optoelectronic wavelength converter or an optical amplifier repeater, is a fiber media converter that integrates a transmitter and a receiver. It can extend the distance of network transmission by converting wavelengths and amplifying optical power. It has the functions of balanced amplification, timing extraction and identification of regenerated optical signals. Today, the common transponders on the market are 10G/25G/100G, of which 10G/25G transponders can realize fiber conversion (such as dual-fiber unidirectional conversion to single-fiber bidirectional), fiber type conversion (multi-mode fiber is converted to single-mode fiber ) and enhancement of optical signals (amplification regeneration, shaping and clock retiming are achieved by converting ordinary wavelength optical signals to ITU-T defined wavelengths); usually used in conjunction with EDFA fiber amplifiers and DCM dispersion compensators, widely used in metro areas network, WDM network, especially in the ultra-long-distance DWDM network. The 100G repeater (ie 100G multiplexer) is mainly developed for 10G/40G/100G transmission and flexible conversion of different optical interfaces, which means that the 100G repeater can support the flexible combination of 10GbE, 40GbE and 100GbE, which can be used in enterprise network , campus network, large data center interconnection, metropolitan area network and some remote applications.

The difference between optical module and transponder
It can be seen from the above that both optical modules and repeaters can convert electrical signals into optical signals, but the difference between the two is:

1. The optical module adopts a serial interface, which can transmit and receive signals inside the optical module; while the repeater adopts a parallel interface, which must be matched with an optical module to achieve signal transmission. Among them, the optical module on one side is used to transmit signals. , and the optical module on the other side is used to receive the signal.

2. Although optical modules can realize photoelectric conversion, transponders can realize photoelectric signal conversion from different wavelengths.

3. Although the converter can easily handle low-rate parallel signals, its size and power consumption are large compared to optical modules.

In simple terms, the transponder can be regarded as a disassembled optical module, but it completes the long-distance WDM network transmission that the optical module cannot achieve.