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An Overview of Long-Distance Optical Transceiver: Definition, Types and Application Cautions

With the development of network tech, long-distance optical transceiver module is in great favour of users who need long-reach data transmission in the optical communication industry. Maybe many people are using the optical module, but having little knowledge of it, such as its definition, its types and its application cautions, etc. Today, Gigalight will have an introduction to it in this article.

The Definition of Long-Distance Optical Transceiver

Transmission distance is regarded as one of key factor of optical module. Optical transceiver is divided into short distance optics, middle distance optics and long distance optics. The transmission distance of long-distance optical transceiver is over 30kms, but it cannot reach the maximum distance in the many situations at the process of its actual application. It is due to that the dispersion appears when optical signal transmitting in the optic fiber. To solve this problem, long-distance optical transceiver takes DFB laser only with one main wavelength as the light source. After that, the dispersion can be avoided.

Types of Long-Distance Optical Transceiver

Among these optical transceivers such as SFP optics, SFP+ optics, XFP optics, 40G QSFP+ optics and 100G QSFP28 optical transceiver, there exist some long-distance optical transceiver modules. Thereinto, long-distance SFP+ optical transceiver adopts EML laser components and optical photodetector components, which reduces the power consumption and raises the accuracy via improvements in many aspects. 40G long-distance optical module adopts driver and modulation unit in the transmitting link, the transmission distance is far more than that of existing standard 40G pluggable optical module.

  • Applications of Long-Distance Optical Transceiver
  • For the interface of switcher
  • For the interface of server
  • For the interface of network card
  • In the security monitoring filed
  • In the telecom field, including data control center and computer room, etc.
  • Ethernet, Fiber Channel(FC), Synchronous Digital Hierachy(SDH), etc.

Cautions for the Utilization of Long Distance Optics

Long-distance optical transceiver has higher requirements for the range of receiving optical power. If the optical power exceeds the range of receiving sensitivity, the failure of optical transceiver module will happen. The use tips and cautions are as follows:

  1. After the installation of long-distance optical module into the device, patch cord can not be connected at once. Using the instruction” display transceiver diagnosis interface” to read the transmitting and receiving optical power of optical transceiver module, checking whether the optical power is in the normal range.
  2. If the condition is allowable, optical power meter can be used to test the optics. After the transmitting and receiving optical power is at the normal range, the optic fiber can be connected into long distance optical transceiver.
  3. In any case, the optic fiber module can not be used to test the long-distance optical module. If it is necessary, it must be connected with the optical attenuator to make the receiving optical power within the normal receiving range.After that, the loopback test can be operated.
  4. Using the long-distance optical module, the receiving optical power must keep some margins. Besides,the actual receiving optical power is reserved at over 3dB compared with the receiving sensitivity. If it can not be achieved, the attenuator needs to be used.
  5. Long distance optical module can be used completey without attenuationin in 10km transmission application. Generally speaking, optical module over 40km will need to be added attunation. It can not be directly connected, or the ROSA is easily burnt.


Above is the introduction to the defintion of long-distance optical module, types of long-distance optical module, and application cautions of long-distance optical module. Generally speaking, long-distance optical module satisfy most users’ requirements for transmission distance to a large degree.It is beleived that long-distance optical module can further meet market demands on performance, power consumption, cost and so on, with the network techs constantly improved. More details are at Gigalight.

About Gigalight:

Gigalight is a design innovator in global optical interconnect field. A series of optical interconnect products include: optical transceivers, passive optical components, active optical cables, GIGAC MTP/MPO cabling, cloud programmers & checkers, etc. Three applications are mainly covered: Data Center & Cloud Computing, MAN & Broadcast Video, and Mobile Network & 5G Optical Transmission. Gigalight takes advantage of its exclusive design to provide clients with one-stop optical network devices and cost-effective products.

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