The fiber-to-the-home (FTTH) access network based on passive optical network technology (PON) is a point-to-multipoint network structure, which uses optical splitters to transmit central office signals to multiple end users. FTTH based on PON technology is the trend of future access network development. With the large-scale promotion of fiber-to-the-home (FTTH) in China, the application of various optical passive products has developed rapidly. As the core passive optical device in fiber-to-the-home (FTTH) construction, the splitter is an important device to ensure the normal transmission of the communication link. With the progress of optical network transformation, the use of splitters is increasing, and the quality of splitters has an increasing impact on optical networks. Choosing suitable, effective and economical splitters and manufacturers will enable us to achieve twice the result with half the effort in network transformation, and effectively reduce the investment and cost in maintenance and management in the later stage.

Section 1  Introduction to Splitter

An optical splitter (i.e., optical splitter) is a connection device with multiple input and output ends. It can realize the coupling, branching, and distribution of optical signals in optical network systems, and is the most important component of optical fiber links. M×N is often used to indicate that an optical splitter has M input ends and N output ends. The optical splitters used in today's networking are generally 1×2 and 1×4 splitters. Choosing primary or secondary splitting has a significant impact on the investment and operating costs of the network. We should choose a splitting method that can save costs and meet future needs based on actual conditions.

Section 2 Types of Splitter

 1. According to different manufacturing processes Currently, there are two common types of optical splitters: PLC optical splitter and FBT optical splitter, namely planar waveguide type splitter and fused taper type splitter.

1) Planar waveguide splitter (PLC)

 Planar waveguide splitter is a micro-optical component product. It uses photolithography technology to form an optical waveguide on a medium or semiconductor substrate to achieve branch distribution function Planar waveguide optical splitter is an integrated waveguide optical power distribution device based on a quartz substrate. It is composed of an optical splitter chip and a fiber array coupled at both ends. The chip is the core component, with an input end and N output end waveguides. The fiber array is located on the upper surface of the chip and sealed with a shell to form an optical splitter with one input and N output fibers. PLC splitters are widely used in FTTx and PON.

2)Fused Taper Splitter (FBT)

Fused Taper Splitter is formed by side-welding two or more optical fibers. Fused Taper technology is to bundle two or more optical fibers with the coating removed together, and then melt and stretch them on a taper machine, and monitor the change of the splitting ratio in real time. When the splitting ratio reaches the requirement, the melt stretching is terminated, and one optical fiber is retained at one end (the rest are cut off) as the input end, and the other end is used as a multi-channel output end.

PLC optical splitter and FBT optical splitter

 The splitting principles of these two types of splitters are similar. They both achieve different branching amounts by changing the mutual coupling of the evanescent field between optical fibers (coupling degree, coupling length) and changing the fiber radius.

The following table compares the differences between the two optical splitters:

According to the different splitting ratios 

According to the different splitting ratios, there are several types of splitters with splitting ratios of 12, 1:4, 1:8, 1:16, 1.32, and 1.64. If necessary, 2:N optical splitters or non-uniform splitting optical splitters can also be used. [Note: On the semiconductor plate, "Y"-shaped waveguide couplers are engraved using photolithography technology. These "Y" waveguides are connected together to form step-by-step splitting, which can achieve splitting ratios of 1×2, 1×4, 1×8, 1×16, 1×32, 1×64, etc.]

Section 3  PLC optical splitter selection guide: common packaging forms and application range

• Bare fiber optical splitter

  The bare fiber splitter is the simplest and most commonly used PLC optical splitter in FTTX projects. This type of PCL splitter has optical fibers left at all ends. Therefore, network engineers can freely splice according to the application. At the same time, the bare fiber PCL splitter only takes up a small amount of space during the wiring process. Therefore, it can be installed in the fiber fusion box to provide distributed signals for FTTH.

• Micro steel tube PLC optical splitter

  A steel tube PLC optical splitter looks like a bare fiber splitter. The main difference from a bare fiber splitter is that the steel tube PLC optical splitter uses a compact stainless steel tube package, usually terminated with a fiber optic connector. Many bare fiber optical splitters also use chips packaged in stainless steel tubes.

• ABS Box PLC Optical Splitter

  ABS Box PLC Optical Splitter uses a plastic box to hold the splitter chip. The input fiber and the output fiber are on a layer of splitter waveguide made of quartz substrate, which can provide easier and more flexible wiring. In addition to providing reliable protection, ABS Box PLC Optical Splitter can also be installed in various wiring cabinets or chassis. It is very common to install an ABS Box PLC Optical Splitter in a standard 19-inch rack unit.

• Micro LGX module PLC optical splitter

  Micro-plug-in PLC optical splitters are currently widely used in FTTx projects, especially in the distribution of FTTx network users. In the case of low space requirements, micro-plug-in PLC optical splitters can provide fast installation and help FTTS project deployment. The figure below shows a basic application of a micro-plug-in PLC optical splitter. The input and output pigtails are easily connected directly to this passive device.

              

  

• Tray-type PLC optical splitter

  The tray-type PLC optical splitter uses a space-saving package to better manage cables. However, it adopts the international 19-inch design and can be deployed in ODF for good cable management and signal transmission. The design clearly marks the ports of the tray-type PLC optical splitter to reduce failures caused by incorrect connections. The figure below shows a tray-type PLC optical splitter.

• Rack-mount PLC Optical Splitter

  The rack-mount PLC optical splitter is designed to meet the requirements of high-density data centers or server rooms. It can be securely mounted on a data center or server rack. Multiple ports can be added to the PLC optical splitter, which is an ideal solution for high-density cabling. Feisu Fiber's (http://Feisu.com) PLC optical splitter can provide up to 64 ports in a 1U 19-inch rack. The picture below shows the details of a 1:8 rack-mount PLC optical splitter.

PLC Fiber Optical Splitter data sheet: