Optical transceiver is an Ethernet transmission media converter unit which transfer a short distance twisted pair electrical signals to optical signals over long distances swap, it is also called the photoelectric converter (Fiber Converter) in many places.

Single-mode fiber optic transceivers: 20-120 km transmission distance. Multimode fiber transceiver: transmission distance up to 2 km. According to the optical fiber, it can be divided into multi-mode fiber optic transceivers and single-mode fiber transceiver. Since the different optical fiber the fiber transceivers used, the transmission distance is different. Generally, the multimode transceiver transmission distance is within 2 km while the single-mode transceiver range from 20 km to 120 km. What should be noted is that due to the different transmission distance, so as the transmission power of the fiber optic transceiver itself, the receiver sensitivity and the working wavelength: Transmitting power of a 2 km fiber optic transceiver is generally between -20 ~-14db, receiver sensitivity -30db with 1310nm wavelength; 120 km fiber-optic transceiver transmitting power is between -5 ~ 0dB receiver sensitivity -38dB, using a wavelength of 1550nm.

According to the required number of optical fiber, they are single-fiber optical fiber transceivers that the received data are transmitted on a single fiber. The essence of an optical multiplexer is to achieve the electro-optical, photoelectric conversion with the images, voice or data signals. To be simple it is just a transmission between electrical signal and optical signal, the purpose is to make various signals transmitted in optical fibers. From the transmission principle, Optical multiplexer can be divided into two kinds: analog multiplexer and digital multiplexer. The formal mainly modulate and demodulate image, voice or data signals by frequency modulation, amplitude modulation and finally output. While the digital multiplexer is transmit by analog-to-digital, digital-to-analog conversion (i.e., 0,1 / 1,0 digital encoding process).

Optical fiber as the transmission medium of optical multiplexer and transceivers, it features small signal attenuation, long transmission distance, good confidentiality, strong anti-interference ability, etc. The optical multiplexer that available on the current market can not only transmit muli-channel video, data and voice signals on a single core fiber but also but also achieve the telephone, computer network, E1 (2M) port, network management, and many other functions transmitting on it, which have saving lots of fiber resource. What’s more the optical multiplexer has the same function with a network video server, which can transmit video and network data at a same time. Besides, the optical multiplexer is also regarded as an universal device that can used to form either a LAN or a public network.