Fiber optic splitter, also known as fiber optic coupler, is a special fiber optic device with one or more input fibers for distributing optical signals into two or more output fibers. Containing no electronics nor requiring power, fiber optic splitter is an integral component and is widely used in most fiber optic networks, especially in passive optical networks such as Ethernet passive optical network (EPON), Gigabit passive optical network (GPON) and fiber to the home (FTTH). There are now two common types of fiber optic splitters in the market: fused biconical taper (FBT) splitter and planar lightwave circuit (PLC) splitter. This article will introduce them from the aspects of operating principles, advantages and disadvantages respectively.
FBT is a traditional technology to weld several fiber together from side of the fiber.
- Operating Principle
A FBT splitter basically consists of two, parallel optical fibers. And these fibers are twisted, stretched and fused together so that their cores are very close to each other, forming a Coupling Region as shown in Figure 1 below. The length of this Coupling Region, L, determines the coupling ratio from one fiber to the other. Therefore, FBT splitters work as a result of an energy transfer by coupling proximity between optical fiber cores.
FBT splitter is made out of materials that are easily available and with low-price. Thus, the price of the FBT splitter is relatively low. Furthermore, the technology of the device manufacturing is relatively simple, which has the impact on its price as well. In addition, as the FBT technology has been developed over a long time, FBT splitters are with high quality.
FBT splitters can only work on three different operating bands (850nm, 1310nm, and 1550nm), which makes them unable to operate on other wavelengths. In other words, FBT splitters are less customizable for different purposes. In addition, the signal processed by FBT splitters cannot be splitted evenly due to lack of management of the signals.
PLC is a more recent technology. And PLC splitters offer a better solution for applications where larger split configurations are required.
- Operating Principle
Through the use of photolithographic techniques, PLC splitters combine a silica glass waveguide process together with precision aligned fiber V-groove arrays to provide a reliable, low cost way to split light from one fiber into many fibers within a very small form factor package.
Compared to FBT splitters, the size of PLC splitters is compact, making it suitable for density applications. Secondly, PLC splitters can operate at wider temperature range (-40 to 85 C), which allows them to be deployed in the areas of extreme climate. Thirdly, the split ratio of PLC splitters can go up to 64, providing a high reliability.
Using a more complex technology of semiconductor, FBT splitters are more difficult to be manufactured. Therefore, the price of this device is higher.
Adopting different technologies, both FBT splitters and PLC splitters have their own advantages and disadvantages. Customers may choose the proper type of splitters according to their needs. As a professional supplier of fiber connectivity network solutions, Fiberstore supplies different models of FBT splitters and PLC splitters which may meet customers’ needs.