The two main types of PON beam splitters are FBT (Fused Biconical Taper) and PLC (Planar Lightwave Circuit), with PLC being preferred for high split ratios and large-scale deployments.

Overview of PON Splitters

In Passive Optical Networks (PON), beam splitters are passive optical devices that divide a single optical signal from the OLT (Optical Line Terminal) into multiple outputs for distribution to end-users (ONTs) without requiring power . They are essential for cost-effective and scalable FTTH (Fiber to the Home) deployments.

FBT (Fused Biconical Taper) Splitters

• Construction: Made by fusing and tapering two or more optical fibers together .
• Advantages: Cost-effective, simple design, suitable for low split ratios such as 1×2 or 1×4 .
• Disadvantages: Limited to low port counts, less uniform light distribution, and sensitive to wavelength variations .
• Use Cases: Ideal for small-scale networks, test environments, or low-density PON deployments .

PLC (Planar Lightwave Circuit) Splitters

• Construction: Fabricated using photolithographic techniques on a silica glass substrate to create precise waveguides .
• Advantages: High reliability, compact size, uniform light distribution, suitable for high split ratios such as 1×16, 1×32, or 1×64 .
• Disadvantages: Higher cost compared to FBT splitters .
• Use Cases: Preferred for large-scale PON deployments, outdoor cabinets, and scenarios requiring consistent signal strength across many outputs .

Split Ratios and Deployment

• FBT splitters are generally used for low split ratios (1:2, 1:4) due to their simplicity and cost efficiency .
• PLC splitters are used for high split ratios (1:8, 1:16, 1:32, 1:64) and are standard in modern GPON and XGS-PON networks for uniform signal distribution .
• Uniform vs Non-uniform: PLC splitters typically provide uniform power distribution, ensuring consistent bandwidth for all subscribers, while FBT splitters may have non-uniform outputs at higher port counts .

Summary

For PON networks, PLC splitters are the dominant choice for large-scale, high-density deployments due to their stability, uniformity, and scalability. FBT splitters remain useful for small-scale or low-port-count applications where cost is a primary concern. Selecting the appropriate splitter type depends on the network size, split ratio requirements, and deployment environment .