Fiber Optic Splitter vs Fiber Optic Coupler：What Are the Differences?

What Is a Fiber Optic Splitter?

A fiber optic splitter is a passive device that divides an optical signal into multiple parts. It is mainly utilized in FTTx/PON networks, where they divide a single fiber into multiple branches to support multiple end users, thus reducing the load on the fiber backbone. Additionally, they are employed in maintaining long-haul networks, cable television, automated teller machine (ATM) circuits, and distributing signals in local/metropolitan area networks.

Fiber splitter typically have at least 2 ports and can have up to 128 ports. The two most commonly used fiber optic splitters are the traditional fused biconical taper (FBT) splitter, which is competitively priced, and the planar lightwave circuit (PLC) splitter, which is compact and suitable for high-density applications.

There are several standard diameters of commonly used fibers in PLC splitters, which relate to the outer dimensions of the fiber. The common fiber diameters include 250 μm, 900 μm, and 2mm. Different fiber diameters are suitable for different packaging and applications. The table below shows some typical PLC splitters.

For more details, please visit FS PLC Splitters.

What Is a Fiber Optic Coupler?

Unlike splitters that are used for signal distribution, fiber couplers can both split one optical signal into multiple signals (distribution) and combine multiple optical signals into a single signal (combining). It is primarily used in scenarios requiring non-point-to-point connections, such as bidirectional links and local area networks (LANs). They also play a crucial role in wavelength-division multiplexing (WDM) systems, where they route, split, monitor networks, and combine signals and pump wavelengths for optical amplifiers.

The number of input and output ports of a fiber coupler is characterized by an N x M configuration, where the letter N represents the number of input fibers, and M represents the number of output fibers. They commonly use multiples of two such as 1x2, 2x2, 1x4, 4x8, etc. Depending on their functions, fiber optic couplers can be divided into WDM couplers, tapered couplers, and fused couplers.

For more information, please check How Do Different Fiber Optic Couplers Work?

Fiber Splitter vs Fiber Coupler: What are the Key Differences?

• Signal Distribution: A fiber optic splitter typically divides one optical signal into multiple channels in equal or specific proportions. It is used to uniformly distribute the signal from a single optical fiber to multiple users or lines. In contrast, a coupler can perform two functions: it can either divide one optical signal into multiple outputs or combine multiple input optical signals into one output. The distribution ratio of a coupler can be designed to different values according to requirements.

• Losses and Proportions: The splitting ratio of fiber optic couplers is not necessarily fixed; it can be 50/50 or other ratios such as 30/70, and can be customized according to actual needs. Fiber optic splitters are more commonly used in scenarios requiring fixed splitting ratios, such as 1x2, 1x4, 1x8, 1x16, 1x32, etc., fixed ratio splitters. When used for distribution at the carrier level, priority is usually given to maintaining uniform signal distribution to ensure that all terminal users in the network receive balanced signal strength.

• Applications: Splitters are commonly used for signal distribution in cable TV networks, antenna systems, and other applications where equal power division is required. Couplers are used for signal monitoring, injection, and extraction in communication systems and test and measurement setups.

Classical Application of Fiber Splitter and Fiber Coupler

As previously described, couplers and splitters refer to two different components. They are positioned similarly in the transmission link, both close to the client end, and their function is to distribute or combine signals. The following will illustrate this with the application case of the most commonly used splitter, the PLC splitter.

PLC splitters are extensively utilized in FTTH networks to distribute optical signals from a central location to multiple homes or premises. The diagram below shows a typical application of a 1x4 PLC splitter. The optical signal from the OLT enters the PLC splitter through a single input fiber. The PLC splitter then evenly divides the incoming optical signal into four different beams according to a predetermined ratio, with each beam carrying the same proportion of the input optical power. After splitting, the optical signals are transmitted to four separate output fibers, distributing the signals to four different users or devices.

Unlike PLC splitters, another type of fiber splitter, the FTB splitter, typically divides the optical signal arbitrarily. It is primarily used in the built-in monitoring ports of some devices, such as the Monitor port on MUX or EDFA. To learn more about their differences, please check: FBT Splitter vs. PLC Splitter: What Are the Differences?

Figure1: typical application of a 1x4 PLC splitter

Conclusion

In summary, splitters vs couplers, as far as the two integral components of optical communication systems, can effectively enhance the transmission efficiency of optical networks and reduce operational costs. FS can provide you with various encapsulations, configurations, and interfaces of PLC Splitters. Additionally, we can offer diversified product customization and solution customization services according to your needs, helping you build a stable and efficient optical transmission network.