Optical splitter is a kind of passive optical device that can divide the input optical signal into multiple output optical signals. It is widely used in passive optical fiber networks. According to different working principles, optical splitters are divided into PLC optical splitters (planar waveguide optical splitters) and FBT optical splitters (fused taper optical splitters)
What is the difference between PLC planar waveguide optical splitter and FBT fused tapered optical splitter? How do we choose both of them？
Overview of PLC optical splitter
The PLC optical splitter is made by the semiconductor process, which can provide a good solution for larger shunt configuration applications. PLC optical splitter is a kind of waveguide fabricated on quartz glass substrate by photolithography technology so that a specific percentage (equal ratio) of light can be routed. Generally, the optical division ratio of the PLC optical splitter is 1:4/:8/:16/:32/:64, including bare fiber PLC optical splitter, micro steel pipe PLC splitter, ABS box PLC optical splitter, PLC optical splitter with splitter, pallet PLC optical splitter, rack PLC optical splitter, LGX optical splitter and micro plug-in PLC optical splitter.
Overview of FBT optical splitter
FBT optical splitter uses traditional passive component manufacturing technology to bind two or more fibers together and realize melting and drawing through a taper drawing machine. Due to the fragility of the fused optical fiber, a glass tube made of epoxy resin and silicon dioxide is usually sheathed outside the fused optical fiber. At the same time, a layer of stainless steel tube is sheathed outside the glass tube, and finally silicon is used for sealing. With the mature development of technology, the cost-effectiveness of FBT optical splitter is getting higher and higher
PLC optical splitter vs FBT optical splitter: what is the difference?
It can be seen from the above that the manufacturing process of PLC optical splitter and FBT optical splitter is different. In addition, the two types of optical splitter also have the following differences:
Operating wavelength
The working wavelength of PLC optical splitter is between 1260nm~1650nm, and the wavelength can be adjusted to support more application environments; However, FBT optical splitter only supports 1310nm/1490nm/1550nm, and cannot work at other wavelengths
Spectral ratio
The splitting ratio refers to the ratio of the input optical signal to the output optical signal of the optical splitter. PLC optical splitter can provide higher reliability. Both PLC and FBT optical splitters can achieve 1:64, but the optical split ratio of FBT optical splitters is variable and supports customization, such as 1:3, 1:7 And 1:11, while PLC optical splitters can only select standard products of 1:2, 1:4, 1:8, 1:16, 1:32 and 1:64.
Spectral uniformity
The PLC optical splitter can achieve uniform light splitting in equal proportion, while the FBT optical splitter is packaged by multiple 1×2 connections, which lacks signal management and cannot achieve uniform light splitting. Moreover, the greater the light splitting ratio, the worse the uniformity, affecting the transmission distance.
Failure Rate
At present, the mature taper drawing process can only pull less than 1×4 at a time. Therefore, when the splitting ratio is greater than 1:8, FBT optical splitter needs more than 7 1×2 connection packages. At this time, errors are easy to occur, leading to failures. In other words, the greater the splitting ratio of FBT optical splitter, the greater the failure rate. The failure rate of PLC optical splitter is much smaller than that of FBT optical splitter, as shown in the following figure.
The cost
The manufacturing process of PLC optical splitter is complex and the chip cost is high; The FBT optical splitter is made of steel, heat shrinkable tubes and other materials. Due to the low material cost and simple device manufacturing technology, the FBT optical splitter is relatively cheaper.
Simply put, the advantages and disadvantages of PLC optical splitter and FBT optical splitter are as follows
| Type | PLC splitter | FBT splitter |
| advantage | Wide working wavelength range(1260-1650nm) | Variable split ratio, support customization, lost cost |
| Spectral uniformity, multi-point | ||
| Low failure rate and high quality | ||
| Adaptable to harsh environments | ||
| disadvantage | Complex manufacturing process | Limited wavelength and uneven light distribution |
| The cost is higher than that of FBT optical splitter within 1:8 light splitting ratio |
In general, PLC optical splitter and FBT optical splitter have many differences in manufacturing process, working wavelength, temperature and so on, except that they are similar in appearance and size.
