Knowledge
Fiber Optic Splitter Types: How PLC and FBT Splitters Work
A fiber optic splitter is a passive optical device that divides an incoming optical signal into multiple output paths at a specified split ratio. Fiber optic splitters are widely used in passive optical networks, including FTTH and FTTB applications, to distribute optical signals to multiple users or network branches.
Based on their manufacturing technologies, fiber optic splitters are commonly divided into two main types: PLC (Planar Lightwave Circuit) splitters and FBT (Fused Biconical Taper) splitters.
Although both technologies divide optical power, they use different methods to achieve optical splitting. Understanding how these fiber optic splitter types work helps explain their characteristics and applications in fiber networks.
What Are the Main Types of Fiber Optic Splitters?
The two main types of fiber optic splitters are:
- PLC fiber optic splitters
- FBT fiber optic splitters
PLC splitters use integrated optical waveguides to distribute optical power among multiple output fibers, while FBT splitters use fused and tapered optical fibers to divide an incoming optical signal.
Their different manufacturing principles influence their available splitting configurations, operating characteristics, and typical applications.
PLC Fiber Optic Splitter
A PLC fiber optic splitter uses planar waveguide technology to divide an incoming optical signal into multiple output paths.
The optical waveguides are fabricated on a silica-based substrate, forming an integrated circuit that distributes optical power among the output channels.
PLC technology supports multiple splitting configurations, including 1×2, 1×4, 1×8, 1×16, 1×32, and 1×64.
It is widely used in FTTH and FTTB networks where optical signals need to be distributed to multiple subscribers.
For example, a 1×16 mini PLC splitter can be installed inside a fiber distribution box to divide one incoming optical signal into 16 output paths.
1×16 Mini PLC Splitter for FTTH Applications
Main Characteristics of PLC Splitters
- Uses integrated planar optical waveguide technology.
- Supports multiple output ports and relatively high split ratios.
- Provides relatively uniform optical power distribution among output channels.
- Commonly supports a broad operating wavelength range, depending on the product design.
- Can be integrated into fiber distribution boxes and other optical distribution equipment.
PLC splitters are particularly suitable for passive optical networks requiring multiple subscriber connections.
Limitations of PLC Splitters
- The manufacturing process is more complicated than that of FBT splitters
- Generally more expensive than FBT splitters for smaller split ratios
- Higher split ratios require larger or more complex packaging
- Performance can be affected by operating temperature and other environmental conditions
FBT Fiber Optic Splitter
An FBT (Fused Biconical Taper) splitter uses a traditional optical fiber coupling process to divide optical power.
During manufacturing, two or more optical fibers are heated, fused, and stretched to form a tapered coupling region. This structure allows optical power to be distributed between output fibers.
FBT splitters are commonly used in relatively low-port-count configurations, such as 1×2 and 1×4, depending on the design.
Unlike PLC splitters, FBT technology can also support customized unequal splitting ratios, such as 70:30 or 90:10.
This makes FBT splitters useful in applications where optical power needs to be divided into different proportions.
Main Characteristics of FBT Splitters
- Uses fused and tapered optical fibers to divide optical signals.
- Commonly used in low-port-count configurations.
- Supports equal or customized unequal splitting ratios.
- Can be manufactured for specific operating wavelengths.
- Available in designs for suitable single-mode or multimode applications.
The optical characteristics of an FBT splitter depend on its coupling structure, splitting ratio, and operating wavelength.
Limitations of FBT Splitters
- Less suitable for large split configurations
- Split performance can vary depending on the specific configuration
- Wavelength-dependent performance can be a consideration in network design
- Temperature-related performance variations may need to be considered
PLC vs. FBT Fiber Optic Splitters
PLC and FBT splitters perform the same basic function but use different optical splitting technologies.
The following table summarizes their main structural and operating differences.
| Feature | PLC Splitter | FBT Splitter |
|---|---|---|
| Technology | Planar Lightwave Circuit | Fused Biconical Taper |
| Operating principle | Integrated optical waveguides | Fused and tapered optical fibers |
| Common configurations | 1×2 to 1×64 | Typically low-port-count configurations |
| Splitting ratio | Usually equal splitting | Equal or customized unequal splitting |
| Wavelength characteristics | Generally broad operating range | Depends on coupling design |
| Output uniformity | Suitable for multiple equal outputs | Depends on design and split ratio |
| Typical applications | FTTH, FTTB, PON | Low-port-count splitting and customized optical distribution |
Both technologies can provide reliable optical splitting when their specifications match the network requirements.
For a more detailed comparison of insertion loss, operating wavelengths, cost, and selection considerations, see our guide to PLC vs. FBT splitters.
Fiber Optic Splitters in FTTH Networks
Fiber optic splitters are essential passive components in FTTH networks, where an optical signal from the network is distributed to multiple subscribers.
PLC splitters are widely used in these networks because they support multiple output ports within a compact optical component.
For example, a 1×8, 1×16, or 1×32 PLC splitter can be integrated into fiber distribution equipment to distribute an incoming optical signal to several subscriber connections.
Different packaging configurations, including mini steel-tube, ABS box, LGX, and cassette designs, allow PLC splitters to be installed in various optical distribution environments.
FBT splitters can also be used in suitable optical distribution applications, particularly where fewer output ports or customized splitting ratios are required.
The selected splitter technology and configuration should match the network architecture, available installation space, and optical performance requirements.
Conclusion
PLC and FBT are two common fiber optic splitter technologies used to divide optical signals in fiber networks.
PLC splitters use integrated planar waveguides and are widely used in FTTH and passive optical networks requiring multiple output connections.
FBT splitters use fused and tapered optical fibers and are commonly applied in low-port-count or customized optical splitting configurations.
Understanding how these two fiber optic splitter types work provides a useful foundation for evaluating their applications in different fiber optic networks.