In-Depth Understanding of Fiber Optic Splitter

WHITE PAPER
In-Depth Understanding
of Fiber Optic Splitter
Fiber optic splitter plays an important role in passive optical network (PON), where a
point-to-multipoint architecture is implemented without any electrically power switching
equipment involved. It is used to enable a single optical fiber to serve multiple end-points, like
customers, without having to provision individual fibers between the hub and customer, which
greatly reduces time and capital cost. In this post, we will introduce fiber optic splitter from three
aspect which can make you have a deep understanding of it.
Fiber Optic Splitter Types: PLC VS. FBT
Generally, based on different working principles, fiber optic splitter can be divided into FBT splitter
and PLC splitter.
• FBT Splitter
Based on traditional technology, FBT (fused biconical taper) splitter contains two fibers which are
placed closely together, typically twisted around each other and fused together by applying heat
while the assembly is being elongated and tapered. It is made out of materials that are easily
available, such as steel, fiber, hot dorm. All of these materials are low-price, making the device itself
inexpensive. With its low cost and easy installation, FBT splitters are widely adopted in passive
networks, especially for instances where the split configuration is smaller (like 1×2, 1×4, 2×2,
etc.). The following figure 1 shows a 2×2 FBT splitter.
Figure 1. 2×2 FBT Splitter
FS.COM White Paper | In-Depth Understanding of Fiber Optic Splitter

WHITE PAPER
• PLC Splitter
PLC (planar lightwave circuit) splitter is the recent addition in fiber optic technology to exhibit
uniform signal splitting among the most advanced optical networks. PLC splitter is a fully passive
optical branching device that is based on planar light wave circuit technology and precision aligning
process, which can evenly split or distribute a single optical signal/input into many outputs with
high accuracy and minimal loss in an efficient manner. PLC splitter is a high-quality device, which
offers a better solution for larger applications. Figure 2 is a picture of 1×64 PLC splitter.
Figure2. 1×64 PLC Splitter
Splitting Ratios: 1×N VS. 2×N
There are a number of splitting ratios available for splitter deployment, but the most common
splitters deployed in a PON system is a uniform power splitter with a 1×N or 2×N splitting ratio,
where the letter “N” means the number of output ports. The 1×N splitters are usually deployed in
networks with a star configuration, while 2×N splitters are more suitable in networks with a ring
configuration as shown in figure 3 to provide physical network redundancy. The optical input power
is distributed uniformly across all output ports. Although non-uniform power distribution is also
available for fiber optic splitters, such splitters are usually custom-made and command a premium.
Besides, based on different data transmission distances, there are also some suggestions for
splitting ratios selection. If your distance between OLT (optical line terminal) and ONU (optical
network unit) is long, like 20 km, you can use splitting ratio 1:32 to receive qualified fiber optic
signals, and when the distance between OLT and ONU is short, like 5 km, you can consider about
1:64 splitting ratio.
Figure 3. Star Configuration VS. Ring Configuration
FS.COM White Paper | In-Depth Understanding of Fiber Optic Splitter

Splitting Levels: Cascaded Splitting VS. Centralized Splitting
WHITE PAPER
Depending on the customer distribution, there are two common deployment strategies of Fiber
optic splitter—cascaded splitting and centralized splitting.
• Cascaded Splitting
In most cases, a cascaded splitter approach as shown in figure 4 has no splitters in the central office.
The OLT port is connected/spliced directly to an outside plant fiber. A first level of splitting (1:4 or
1:8) is installed in a closure, not far from the central office. A second level of splitters (1:16 or 1:8)
resides in terminal boxes, very close to the customer premises (each splitter covering 8 to 16
homes). The inputs of these splitters are the fibers coming from the outputs of the first level
splitters described above.
Figure 4. Cascaded Splitter Approach
• Centralized Splitting
A centralized splitter approach generally uses a combined splitting ratio of 1:64 (with a 1:2 splitter in
the central office, and a 1:32 in an outside plant enclosure such as cabinet). These single-stage
splitters can be placed at several locations in the network or housed at a central location. The 1:64
splitter could even be placed within the central office to provide a point-to-multipoint (P2P) outside
plant network that still shares bandwidth across multiple customers as shown in figure 5, for
instance a group of subscribers a short distance from the central office. But most often, the splitters
are placed in the outside plant to reduce the amount of overall fiber required.
Figure 5. Centralized Splitting Approach
FS.COM White Paper | In-Depth Understanding of Fiber Optic Splitter

Summary
WHITE PAPER
Most FTTH applications are favored PON network, which offers many favorable advantages. Fiber
optic splitter, as an indispensable component in PON networks, are gained much attention. We have
mentioned three aspects of fiber optic splitters, including common types, common splitting ratios,
and common splitting levels, which can help you choose the suitable splitters for your project.
FS.COM White Paper | In-Depth Understanding of Fiber Optic Splitter

WHITE PAPER
Contact Us
Manufacturing R & D (China)
Eastern Side, Second Floor, Science &
Technology Park, No.6, Keyuan Road,
Nanshan District, Shenzhen 518057,
China
Tel: +86 (755) 8300 3611
Fax: +86 (755) 8326 9395
Email: sales@fs.com
APAC Office (Hong Kong)
1220 Tung Chun Commercial Centre,
438-444 Shanghai Street, Kowloon,
HongKong
Tel: +(852) 817 636 06
Fax: +(852) 817 636 06
Email: sales@fs.com
North America (United States)
331 Andover Park East Ste330, Tukwila,
WA 98188,United States
Tel: +1 (253) 277 3058
Fax: +1 (253) 246-7881
Email: sales@fs.com
London Office (United Kingdom)
Third Floor 207 Regent Street, London,
W1B 3HH, United Kingdom
Tel: +44 (020) 3287 6810
Follow us
LinkedIn
Twitter
Facebook
G+
Pinterest
Youtube
Blog
Notice: This document is for informational purposes only and does not set forth any warranty, expressed or
implied, concerning any equipment, equipment features, or service offered or to be offered by FS.COM.
FS.COM reserves the right to make changes to this document at any time, without notice, and assumes no
responsibility for its use. This information document describes features that may not be currently available.
Contact a FS.COM sales team for information on feature and product availability.
FS.COM White Paper | In-Depth Understanding of Fiber Optic Splitter