what the Differences Between FBT Splitter and PLC Splitter

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In FTTx and PON architectures, optical
splitter plays an increasingly significant role to create a variety of
point-to-multipoint fiber optic networks. But do you know what is a fiber optic
splitter? In fact, a fiber optic splitter is a passive optical device that can
split or separate an incident light beam into two or more light beams.
Basically, there are two types of fiber splitter classified by their working
principle: fused biconical taper splitter (FBT splitter) and planar lightwave
circuit splitter (PLC splitter). You may have one question: what’s the
difference between them and shall we use FBT or PLC splitter?

 

What Is FBT Splitter?

FBT
splitter is based on a
traditional technology to weld several fiber together from side of the fiber.
Fibers are aligned by heating for a specific location and length. Because the
fused fibers are very 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 the technology continues developing, the quality
of FBT splitter is very good and it can be applied in a cost-effective way.

 

What Is PLC Splitter?

PLC splitter is based on planar
lightwave circuit technology. It composes of three layers: a substrate, a
waveguide, and a lid. The waveguide plays a key role in the splittering 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. Therefore, if high split counts are needed, small
package size and low insertion loss are also required, you are suggested to
choose PLC splitter rather than FBT splitter. For more information about PLC
splitter, please refer to How Much Do You Know About PLC Splitter?

 

FBT vs. PLC Splitter

(1) Operating Wavelength

FBT splitter can only support three
wavelengths: 850nm, 1310nm and 1550nm, which makes its inability to works on
other wavelengths. While PLC splitter can support wavelength from 1260 to
1650nm. The adjustable rang of wavelength makes PLC splitter suitable for more
applications.

 

(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 splitted 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 customisable, and the special types are 1:3, 1:7, 1:11, etc.
But PLC splitter is non-customisable, and it has only standard version like
1:2, 1:4, 1:8, 1:16, 1:32 and so on.

 

(3) Assymetric Attenuation Per Branch

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

 

(4) Failure Rate

FBT splitter is typically used for
networks requiring the splitter configuration of less than 4 splits. The larger
the split, the larger failure rate. When its splitting ratio is larger than
1:8, more errors will occur and cause 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.

 

(5) Temperature Dependent Loss

In certain areas, 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 relatively good performance in the areas of extreme climate.

 

(6) Price

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

 

Conclusion

Although the outer appearance and size
of FBT and PLC fiber splitter seem rather similar, their internal technologies
and specifications differ in various 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.