Optical Splitter Classification

Optical splitters are classified primarily into two types: Planar Lightwave Circuit (PLC) splitters and Fused Biconical Taper (FBT) splitters, each suited for different network scales and applications.

Overview of Optical Splitters

An optical splitter, also called a fiber splitter or beam splitter, is a passive optical device that divides a single input optical signal into multiple outputs or combines multiple inputs into one output without requiring external power . They are essential in Passive Optical Networks (PONs), enabling cost-efficient distribution of signals from a central Optical Line Terminal (OLT) to multiple Optical Network Terminals (ONTs) in FTTH deployments . Key performance metrics include split ratio, insertion loss, and uniformity of output power .

Classification by Manufacturing Technology

1. Planar Lightwave Circuit (PLC) Splitters

• Manufacturing Process: PLC splitters are fabricated using semiconductor lithography on a quartz substrate, creating a micro-scale optical waveguide array .
• Configuration: Commonly available in 1×N or 2×N configurations, where one or two inputs are split into multiple outputs.
• Advantages: High uniformity, low insertion loss, compact size, and excellent reliability across a wide range of wavelengths.
• Applications: Ideal for large-scale networks with high split ratios (e.g., 1×32, 1×64), such as urban FTTH deployments .

2. Fused Biconical Taper (FBT) Splitters

• Manufacturing Process: FBT splitters are made by fusing and tapering two or more optical fibers at high temperatures to form a coupling region .
• Configuration: Typically used for small split ratios like 1:2 or 1:4.
• Advantages: Lower cost and simpler manufacturing process.
• Limitations: Performance can be affected by temperature variations and is less uniform for high split ratios.
• Applications: Suitable for small-scale networks or short-distance distribution where cost is a priority .

Classification by Split Ratio

Optical splitters can also be categorized based on how the input signal is divided:

• Equal Splitters: Distribute optical power evenly across all outputs (e.g., 1×4, 1×8).
• Unequal Splitters: Allocate different power levels to outputs, useful for networks requiring prioritized signal distribution .

Summary

In practice, PLC splitters dominate modern FTTH networks due to their scalability, reliability, and uniform performance, while FBT splitters remain cost-effective for smaller deployments. Choosing the right type depends on network size, split ratio requirements, environmental conditions, and budget considerations .