Fiber Optic Splitter Application in PON Networks

What is Fiber Optic Splitter?

Fiber optic splitter, or sometimes called as beam splitter, is a passive optical component that can split an incident light beam into two or more light beams, and vice versa. The device contains multiple input and output ends. Whenever the light transmission in a network needs to be divided, fiber optic splitter can be implemented for the convenience of network interconnections.

Just like fiber patch cable, fiber splitters are usually with 0.9mm, 2mm or 3mm cables. 0.9mm outer diameter cable is mostly used in stainless steel tube package fiber optic splitters, while 2mm and 3mm cables are mostly used in box type package fiber splitters. Based on working wavelength difference there are a single window and dual window fiber optic splitters. And there are single mode fiber splitter and multimode fiber splitter. The picture below shows an optical splitter.

How Does Fiber Optic Splitter Work?

In general, a optical splitter has many input and output terminals to attain the branch of the light beams, maximize the functionality of optical network circuits. The passive optical splitter can split, or separate, an incident light beam into several light beams at a certain ratio.
As for the working principle of fiber optic splitter, it can be generally described in the following way. When the light signal transmits in a single-mode fiber, the light energy can not entirely concentrated in the fiber core. A small amount of energy will be spread through the cladding of fiber. That is to say, if two fibers are close enough to each other, the transmitting light in an optical fiber can enter into another optical fiber. Therefore, the reallocation technique of optical signal can be achieved in multiple fibers. And this is how fiber optic splitter comes into being.

As a simple example, how optical splitter with 1×4 split configurations can separate an incident light beam from a single input fiber cable into four light beams, 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.

The optical splitter with 2x64 split configurations is a little bit more complicated than the 1x4 split configurations. There are two input terminals and sixty-four output terminals in the optical splitter in 2x64 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. With the rapid growth of FTTx worldwide, the requirement for larger split configurations in networks has increased to serve mass subscribers.

Classification of Fiber Optic Splitter

The simplest couplers are fiber optic splitters. These devices possess at least three ports but may have more than 32 for more complex devices. Fiber optic splitters are important passive components used in FTTx networks. Two kinds of fiber splitters are most used: one is the traditional fused type fiber optic splitter FBT (fused biconical taper) splitter, which features competitive prices. And the other is PLC (planar lightwave circuit) fiber optic splitter, which is of compact size and suit for density applications.

• PLC splitter divides the incoming signal into multiple outputs by using an optic splitter chip. One optic splitter chip is able to achieve at most 64 ends. PLC splitter is usually used for larger applications. The losses of PLC splitter are not sensitive to the wavelength, which satisfies the need for multiple wavelengths transmission. PLC splitter’s configuration is compact and its size is small, thus the installation space can be greatly saved.
• FBT splitter is fused with a heat source similar to a one-to-one fusion splice. Fibers are stretched under a heating zone to form a double cone. The cost of FBT splitter is lower due to the commonly used materials, and the splitting ratio is adjustable. But the losses are sensitive to wavelengths. Device should be chosen according to wavelengths. And it is unable to offer the uniform spectroscopy.

Check the following PLC Splitter vs FBT Splitter Comparison Chart:

Fiber Optic Splitter Application in PON Networks

Fiber optic splitter can be used for FTTx/PON application. This helps to reduce the physical fiber usage or the basic quantity of required fibers. A single fiber can be split into many branches to support multiple end users. The strain on the fiber backbone can be greatly decreased through the application. In addition, fiber optic splitter can also be employed in the maintenance of long-haul network, cable TV ATM circuit or local area/metro area network. Optical splitters, enabling the signal on the optical fiber to be distributed between two or more optical fibers with different separation configurations (1×N or M×N), have been widely used in PON networks. An optical splitter is often used in the ODN to help multiple end-users share a PON interface. Point-to-multipoint FTTH network deployment can be further divided into the centralized (single-stage) or cascaded (multi-stage) splitter configurations in the distribution portion of the FTTH network.

Conclusion

Fiber optic splitters enable a signal on an optical fiber to be distributed among two or more fibers. Since splitters contain no electronics nor require power, they are an integral component and widely used in most fiber-optic networks. Thus, choosing fiber optic splitters to help increase the efficient use of optical infrastructure is key to developing a network architecture that will last well into the future.

LightOptics provides all the above fiber optic splitters. Please visit www.lightoptics.co.uk for more information.