Optical splitters are passive devices that divide or combine optical signals, primarily categorized into PLC (Planar Lightwave Circuit) and FBT (Fused Biconic Tapered) types.

Overview

An optical splitter, also known as a fiber optic splitter or beam splitter, is a passive device that splits a single input optical signal into multiple outputs or combines multiple inputs into one. They are widely used in Passive Optical Networks (PON), FTTH, FTTX, and other fiber optic systems to efficiently distribute signals without requiring power .

Main Types of Optical Splitters

1. Planar Lightwave Circuit (PLC) Splitters

• Working Principle: PLC splitters use integrated waveguide technology on a quartz substrate, manufactured with semiconductor processes to distribute optical signals evenly .
• Features:
  • Low insertion loss and high uniformity across outputs
  • Wide wavelength range compatibility
  • Compact, lightweight, and easy to install
  • Can support high split ratios (e.g., 1×32, 1×64)
• Applications: Optical routing, network monitoring, distributed sensing, and large-scale FTTH deployments
• Variants:
  • Bare Fiber PLC Splitter: No connectors, spliced directly to fibers; suitable for permanent installations
  • Micro Tube PLC Splitter: Encapsulated in micro steel tubes; easier installation in junction or terminal boxes

2. Fused Biconic Tapered (FBT) Splitters

• Working Principle: FBT splitters are made by fusing and tapering two or more fibers together, allowing light to couple between fibers .
• Features:
  • Cost-effective for low-channel splitters
  • Simple manufacturing process
  • Split ratios can be customized but less uniform than PLC
• Applications: Small-scale networks, local distribution, and scenarios where fewer output channels are needed

Split Ratios and Configurations

• Balanced Splitters: Distribute optical power equally among outputs (e.g., 1×4, 1×8, 1×32)
• Unbalanced Splitters: Allocate different power levels to outputs to optimize fiber usage (e.g., 1×5 with 20%, 33%, 50%, 75%, 95% distribution),
• Multi-Input Splitters: Configurations like 2×8, 2×32, or 2×64 allow combining multiple input signals into multiple outputs

Packaging Types

• Box Type: Suitable for indoor installations and patch panels
• Stainless Tube Type: Durable for outdoor or harsh environments
• Compact Modules: Designed for junction boxes or terminal boxes

Key Considerations

• Insertion Loss: Signal attenuation due to splitting
• Uniformity: Consistency of output power across all ports
• Wavelength Insensitivity: PLC splitters are generally more stable across different wavelengths
• Durability and Reliability: PLC splitters offer higher long-term stability, while FBT splitters are simpler but less uniform Optical splitters are essential for efficient signal distribution in fiber networks, and the choice between PLC and FBT depends on network scale, split ratio, installation environment, and cost considerations .