When you’re planning or expanding a fiber optics network, there are many things to consider. The networks grow in complication very quickly, and any miscalculation can prove expensive, if not serious.

Figure1, Some Pictures of Transceiver

The following tips are important factors to consider when choosing an optical transceiver:

1.Speed / Data Rate

Speed is a major concern. When it comes to fiber optics, you can get networks that are incredibly fast, but they are not cheap. Likewise, if you are trying to save money, sacrificing speed is one of the easiest ways to lower costs.

What data rates do you need for your network to function? You have to answer this question first. Then, you want to think about the future and how your data rates might grow over time. When you consider both aspects of data rates, you can pick the right transceiver. Higher data rates do not always mean a better network. Balancing your network performance needs with cost are more important.

While there are a variety of transceivers out there that can handle a wide range of data rates, the most popular used transceivers are usually live in the following data rate categories:

1 Gbps

10 Gbps

25 Gbps

40 Gbps

100 Gbps

200 Gbps

400 Gbps

800 Gbps

2.Packaging / Form Factor

The international standard multi-source agreement (MSA) defines the different transceiver form factors. Popular form factors include SFP, SFP+, XFP, CFP, CFP2, SFP28, QSFP+, QSFP28, QSFP56, QSFP-DD, OSFP and so on. Each form factor matches the transceiver cage of the device. Always ensure that your transceiver is compatible with your network switch.

Figure 2, Some cages with different dimension of different form factor

GBIC:Gigabit Interface Converter

SFF: Small Form Factor

SFP: Small Form-factor Pluggable

SFP+: Enhanced Small Form Factor Pluggable Module

SFP28: 25 Gigabit Small Form factor Pluggable

XFP: 10G Small Form Factor Pluggable

QSFP+: Quad Small Form-factor Pluggable Plus

CFP: Centum Form Factor Pluggable

AOC: Active optical cable

QSFP28:Quad (4-channel) small form factor hot Pluggable

QSFP-DD: Quad Small Form Pluggable Double Density

OSFP: Octal Small Form Factor Pluggable

3.Transmission Distance/ Reach

Different transceiver modules support different transmission distances. In general, the transmission distance of a multi-mode transceiver module is much shorter than a single-mode transceiver module and the price is also cheaper. For example, 10GBASE-SR SFP+ transceiver can only reach up to 300m, while 10GBASE-ZR SFP+ transceiver can reach up to 80km, so it is important to determine the distance you need to transmit. In addition, taking into account the attenuation and dispersion of optical signals during transmission, we recommend that you use optical transceivers that support slightly larger transmission distances than you actually need.

The main standard name of transceiver reach distance are live in following categories:

CR: Copper Reach, 3m

VR: Vertical Reach, 50m

SR: Short Reach, 100m

DR: Data Center Reach, 500m

FR: Fast Reach, 2km

LR: Long Reach, 10km

ER: Extended Reach, 40km

ZR: Ze Best Reach, 80km

XR: Varible Reach and data rate.

4.Fiber Type/ Medium

Fiber have defined industry standards.  Different fiber cable types have different fiber loss at their working wavelengths as shown in the TIA-568-C.0- 2 standards shown below. This table provides a good loss approximation, but in practice the true loss of a link should always be measured  with an OTDR (Optical Time Domain Reflector meter) trace.

Table 1, Typical Fiber Loss in Main Wavelengths

You can identify the fiber type by its colour. Single-mode fiber is yellow colour, while multimode fiber is either orange/ cyan/ purple colour. This helps to ensure the correct transceiver is used in your network.

5.Connector/ Optical Interface

The most common types of transceiver connectors used in optical transceiver are LC and MPO though there are some new types of connectors available now.

Figure 3, Diagram of some optical interfaces

6.Working Temperature/ Case Temperature

Common applications need only commercial temperature transceivers at 0 to 70C. There is extended ( -20 to 85C) and industrial temperature (-40 to 85C) transceivers for outdoor and rugged applications. In here, the temperature is defined to be the case temperature, instead of environment temperature.

CT/C-Temp, commercial temperature: 0~70℃

ET/E-Temp, extended temperature: -20~85℃

IT/I-Temp, industrial temperature: -40~85℃

Figure 4, The test temperature in transceiver case

For more information, visit Etern Optoelectronics website: https://www.szetern.com, or email to: sales@szetern.com