What is a fiber optic splitter?
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What is a fiber optic splitter?

Posted on by FS.COM

The fiber optic splitter is also referred to as beam splitter, which is an integrated waveguide optical power distribution device. It plays an important role in passive optical network by allowing a single PON interface to be shared among many subscribers. To achieve this, it is designed to split an incident light beam into two or more light beams and couple the light beams to the branch distribution as an optical fiber tandem device, which has the function to maximize the performance of network circuits.

The Characteristics of Fiber Optic Splitter

The fiber optic splitter can be terminated with different forms of connectors, and the primary package could be box type or stainless tube type. The first package is usually used with 2mm or 3mm outer diameter cable, the other is normally used in combination with 0.9mm outer diameter cables. Besides, it has variously different split configurations, such as 1×2, 1×8, 2×32, etc. With the development of the splitter manufacturing technology, the fiber optic market can support the high-technical splitter used in the network where the split configurations are 2×64 or larger at present.

According to the different transmission medium, there are single-mode fiber optic splitter and multimode fiber optic splitter. For multimode ones, the phrase implies that the fiber is optimized for 850nm and 1310nm operation. For single-mode ones, the phrase means that the fiber is optimized for 1310nm and 1550nm operation. Meanwhile, based on working wavelength difference, there are single window and dual window fiber optic splitters. The single window fiber optic splitter is to use one working wavelength, while the dual window fiber optic splitter is with two working wavelengths.

In general, a fiber optic splitter has many input and output terminals to attain the branch of the light beams and maximize the functionality of optical network circuits, which plays an important role in passive optical network (EPON, GPON, BPON, FTTX, FTTH and so on).

How Does the Fiber Optic Splitter Work?

The fiber optical splitter is a passive optical device that can split, or separate, an incident light beam into several light beams at a certain ratio. As a simple example, Figure 1 shows how splitter with 1×4 split configurations can separate an incident light beam from a single input fiber cable into four light beams and transmit them through four individual output fiber cables. For instance, if the input fiber optic cable carries 1000 Mbps bandwidth, each user in the end of output fiber cables can use the network with 250 Mbps bandwidth.

Fiber optic splitter

The working principle of fiber optical splitter with 1:4 split ratios.

As for the fiber optic splitter with 2×64 split configurations, it is more complicated than the splitter with 1×4 split configurations. There are two input terminals and sixty-four output terminals in the fiber optic splitter with 2×64 split configurations. Its function is to split two incident light beams from two individual input fiber cables into sixty-four light beams and transmit them through sixty-four light individual output fiber cables.

What should be noted is that the ejected light beams may or may not have the same optical power as the incident light beam. The designer would better to take it into consideration when designing the passive optical networks.

Two Types of Fiber Optic Splitters Classified by Manufacturing Technique

On the basis of different manufacturing technique, the fiber optic splitter can be divided into two types, which are popularly used nowadays. One is the traditional fused type optical splitter, fused biconic tapered (FBT) splitter, which features competitive prices; and the other is planar lightwave circuit (PLC) splitter, which has compact size and suits for high-density applications. Both of them have the advantages and can be used in different applications.

Fused Biconic Tapered (FBT) Splitters

The FBT splitter (See Figure 2) is fabricated by the traditional technology with over 20 years history. Its manufacturing technique is relatively mature and the manufacturing cost is lower than PLC splitter, so that the FBT splitter can be deployed in a cost-effective manner in today’s fiber optic market.

FBT splitter

FBT splitters

In the manufacturing process of FBT splitter, there are two or more fibers placed closely together, typically twisted around each other and fused together by applying heat while the assembly is being elongated and tapered. The fused fibers are protected by a glass substrate and then protected by a stainless steel tube. Meanwhile, there is a signal source controls the desired coupling ratio to meet the requirements in applications.

Nowadays, FBT splitters are widely used in passive optical networks, especially in the network where the split configuration is not larger than 1×4. In fact, there is a slight drawback of FBT splitter, the split configuration. Detailedly, if more than four splits are required, multiple FBT splitters can be spliced together in concatenation to multiply the amount of splits available, like a tree splitter. By using this design, the package size increases due to multiple FBT splitters and the insertion loss also increases with the additional splitters. Therefore, if high split counts are needed, small package size and low insertion loss are also required, you are suggested to choose a PLC splitter, instead of the FBT splitter.

Planar Lightwave Circuit (PLC) Splitters

With a more recent technology, the PLC splitter (See Figure 3) provides a better solution for applications with larger split configurations. Clearly different from the manufacturing technique of FBT splitters, in the manufacturing process of PLC splitters, the waveguides are fabricated by using lithography onto a silica glass substrate, which allows for routing specific percentages of light. As a result, the PLC splitter offers very accurate splits with minimal loss in an efficient package.

PLC splitter

PLC splitters

With the rapid growth of FTTx worldwide, the requirement for larger split configurations (1×32, 2×64, etc.) in these networks has also grown in order to serve mass subscribers. Due to its performance benefit of larger split configurations, the PLC splitter is more commonly used in the network where the split configuration is larger than 1×4.


With the fast development of optical network, more and more experts attach great importance to the fiber optic splitter, and try to optimize its function as much as possible. As a result, the fiber optic splitters becomes diversiform with different design aims, which can be used in different applications. FS.COM provides a variety of fiber optic splitters which suit for many applications, all of them are tested in-house prior to shipping to guarantee that they will arrive in perfect physical and working condition. We also guarantee the fiber optic splitters to work in your system with a lifetime advance replacement warranty. Your choice is our motivation. Welcome to FS.COM.

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