What Are the Differences Between PLC Splitter and FBT Splitter?

The optical splitter is one of the most important passive components in the optical fiber link and is a fiber tandem device that can have multiple inputs and multiple outputs. The commonly used Mx N indicates that an optical splitter has M input ports and N output ports. What is PLC Splitter?

Working principle of optical splitter

When a single-mode optical fiber conducts optical signals. The light energy not completely concentrated in the core. And a small amount is transmitted through the cladding close to the core. In other words, if the cores of the two optical fibers are close enough. The mode field of the light transmitted in one optical fiber can enter the other optical fiber. And the optical signal redistributed in the two optical fibers.

At present, there are two types of optical splitters that can meet the needs of optical splitters: one is the planar lightwave circuit (PLC) splitter produced based on optical integration technology. The other is the fused biconical tape (FBT) splitter produced by traditional optical passive devices. Manufacturers use the traditional fused biconical tape process. These two types of equipment have their own advantages. Users can reasonably choose these two types of splitting equipment according to different applications and needs. UnitekFiber briefly introduces PLC fiber optic splitters and FTB splitters.

PLC optical splitter (planar lightwave circuit)

Planar lightwave circuit technology is the use of semiconductor technology to manufacture optical lightwave branching devices. The branching function completed on the chip. It can implement up to 1X32 splitters on a chip. Then, the input and output multi-channel fiber arrays coupled at both ends of the chip.

The advantage of the PLC optical coupler is that the loss is insensitive to the wavelength of the transmitted light. And can meet the transmission needs of different wavelengths. The light evenly distributed and the signal can be evenly distributed to the user. It has a compact structure and a small size. And can directly installed in various existing splitter boxes without leaving a large installation space. A single device has many split channels, which can reach more than 32 channels. The PLC fiber splitter has low multi-channel cost.

FBT splitter

The fused biconical taper technology is to bundle two or more optical fibers together. Then melt and stretch them on a taper machine. And monitor the changes in the splitting ratio in real time. After the splitting ratio reaches the requirement, the melting and stretching ends. One end retains one optical fiber (the rest is cut off) as input. And the other end used as a multi-channel output.

The main advantage of the FBT splitter is that the tapered coupler has more than 20 years of history and experience. Many equipment and processes can be used, and the development expenditure is only one-tenth or even one-hundredth of that of the PLC splitter. The splitting ratio can monitored in real time as needed, and unequal splitters can made.

The main disadvantage of the FBT splitter is that the loss is sensitive to the wavelength of light, and the device generally selected according to the wavelength. This is a fatal flaw in the use of triple-network integration, because the optical signals transmitted in triple-network integration are signals with wavelengths of 1310nm, 1490nm, and 1550nm. The optical uniformity of FBT splitters is poor, the nominal maximum difference of 1X4 is about 1.5dB, and the difference is greater than 1×8, which cannot ensure uniform splitting and may affect the overall transmission distance. The insertion loss varies greatly with temperature. FBT splitters (such as 1x 16, 1×32) are relatively large, the reliability will reduced. And the installation space  limited.

PLC splitters and FBT splitters have their own advantages in performance and price. And both process technologies constantly upgraded to continuously overcome their shortcomings. FBT splitters are solving the problems of less one-time taper and poor uniformity. And PLC splitters are also making unremitting efforts to reduce costs. At present, the cost of the two devices above 1X8 is almost the same. With the increase of split channels, the price of planar waveguide splitters is better.

How to Choose PLC Splitter and FBT Splitter

How to choose these two devices, PLC splitters and FBT splitters, depends on the application and user requirements. In some applications where volume and optical wavelength are not very sensitive, especially when there are few branches, it is more economical to choose FBT splitters. For independent data transmission, use 1310nm FBT splitter. TV video network can choose 1550nm FBT splitter. In the case of three-in-one, FTTH and other situations where multiple wavelengths of optical transmission and many users required, PLC splitter should be selected.