Differences Between FBT Splitter and PLC Splitter

Fiber optic splitter is a passive optical device that can split or separate an incident light beam into two or more light beams. There are two types of optical fiber splitter classified by their working principle: FBT splitter (fused biconical taper splitter) and PLC splitter (planar lightwave circuit splitter). There are lots of differences between FBT splitter and PLC splitter, which is confusing for many users. This tutorial will walk you through the main ones between them.

What Is PLC Splitter?

PLC splitter is based on planar lightwave circuit technology. It comprises three layers: a substrate, a waveguide, and a lid. The waveguide plays a key role in the splitting process which allows for passing specific percentages of light. So, the signal can be split equally. In addition, PLC splitters are available in a variety of split ratios, including 1:4, 1:8, 1:16, 1:32, 1:64, etc. They also have several types, such as bare PLC splitter, blockless PLC splitter, fanout PLC splitter, mini plug-in type PLC splitter, etc. The following table shows the advantages and disadvantages of PLC splitter.

Suitable for multiple operating wavelengths (1260nm – 1650nm). Equal splitter ratios for all branches. Compact configuration, smaller size, small occupation space. Good stability across all ratios. High quality, low failure rate.Complicated production process. Costlier than the FBT splitter in the smaller ratios.
Advantages and disadvantages of a PLC splitter

What Is FBT Splitter?

FBT splitter is based on traditional technology to weld several fibers together from the side of the fiber. Fibers are aligned by heating for a specific location and length. Given that the fused fibers are fragile, they are protected by a glass tube made of epoxy and silica powder. And then a stainless-steel tube covers the inner glass tube and is sealed by silicon. As technology continues to develop, the quality of FBT splitter is very good and it can be applied in a cost-effective way. The following table shows the advantages and disadvantages of FBT splitter.

FBT splitter is made of materials that are easily available and low-price, so it is cheaper. Splitter ratios can be customized.Restricted to its operating wavelength (850nm, 1310nm, and 1550nm). The maximum insertion loss will vary depending on the split and increase for those splits over 1:8. Because an exact equal ratio cannot be ensured, the transmission distance can be affected. High Temperature Dependent Loss (TDL). Susceptible to failure due to extreme temperatures or improper handling.
Advantages and disadvantages of FBT Splitter

FBT Splitter vs PLC Splitter: What Are the Differences?

1. Operating Wavelength

FBT splitter only supports three wavelengths: 850nm, 1310nm, and 1550nm, which makes it’s inability to work on other wavelengths. The PLC splitter can support wavelengths from 1260 to 1650nm. The adjustable range of wavelength makes PLC splitter suitable for more applications.

FBT vs PLC splitter, Operating Wavelength

2. Splitting Ratio

Splitting ratio is decided by the inputs and outputs of an optical cable splitter. The maximum split ratio of FBT splitter is up to 1:32, which means one or two inputs can be split into an output maximum of 32 fibers at a time. However, the split ratio of PLC splitter is up to 1:64 – one or two inputs with an output maximum of 64 fibers. Besides, FBT splitter is customizable, and the special types are 1:3, 1:7, 1:11, etc. But PLC splitter is non-customizable, and it has only standard versions like 1:2, 1:4, 1:8, 1:16, 1:32, and so on.

FBT vs PLC splitter, Splitting Ratio

3. Asymmetric Attenuation Per Branch

The signal processed by FBT splitters cannot be split evenly due to a lack of management of the signals, so its transmission distance can be affected. However, PLC splitter can support equal splitter ratios for all branches, which can ensure a more stable optical transmission.

FBT vs PLC splitter, Asymmetric Attenuation Per Branch

4. Failure Rate

FBT splitter is typically used for networks requiring the splitter configuration of less than 4 splits. The larger the split, the greater the failure rate. When its splitting ratio is larger than 1:8, more errors will occur and cause a higher failure rate. Thus, FBT splitter is more restricted to the number of splits in one coupling. But the failure rate of PLC splitter is much smaller.

FBT vs PLC splitter, Failure Rate

5. Temperature-Dependent Loss

In certain areas, the temperature can be a crucial factor that affects the insertion loss of optical components. FBT splitter can work stable under the temperature of -5 to 75℃. PLC splitter can work at a wider temperature range of -40 to 85 ℃, providing satisfactory performance in the areas of extreme climate.

6. Price

Owing to the complicated manufacturing technology of PLC splitter, its cost is higher than FBT splitter’s. If your application is simple and short of funds, FBT splitter can provide a cost-effective solution.


Although the outer appearance and size of FBT and PLC fiber splitter seem similar, their internal technologies and specifications differ in several ways. Over the past few years, splitter technology has made a huge step forward in the past few years by introducing PLC splitter. It has proven itself as a higher reliable type of device compared to the traditional FBT splitter. If high split counts, small package size, and low insertion loss are required, you are suggested to choose PLC splitter rather than FBT splitter.