Passive Fiber Optic LAN Splitter

A passive fiber optic LAN splitter is a device that divides a single optical signal into multiple outputs without requiring power, enabling one fiber to serve multiple endpoints in a PON network.

Function and Purpose

A passive fiber optic splitter is a passive device that splits one optical input from an Optical Line Terminal (OLT) into multiple outputs for Optical Network Terminals (ONTs) or Units (ONUs) without active electronics or power supply . It allows a single fiber to serve multiple users, making Fiber-To-The-Home (FTTH) and LAN deployments scalable and cost-efficient . The splitter reduces the optical power per output according to the split ratio, typically in factors of 2 (1×2, 1×4, 1×8, 1×16, 1×32, 1×64), though odd ratios like 1×3 or 1×5 are also used .

Types of Splitters

There are two main types of passive splitters:

• PLC (Planar Lightwave Circuit) Splitters: Compact, stable, and suitable for high split ratios (1×8, 1×16, 1×32). PLC splitters are widely used in outdoor cabinets and wall-mounted enclosures .
• FBT (Fused Biconical Taper) Splitters: Lower-cost, suitable for small split ratios or test environments. FBT splitters are less uniform and less stable than PLC for large deployments .

Architectures

Splitters can be deployed in two main architectures:

• Centralized Splitters: Located in a central office or fiber distribution hub, allowing flexible reconfiguration via jumpers. This setup reduces fiber usage on the feeder side and simplifies management .
• Distributed Splitters: Placed closer to end-users in closures or pedestals. Once installed, the connections are fixed, and reconfiguration is limited .

Technical Considerations

• Split Ratio: Determines the number of outputs and the optical power per leg. Higher split ratios reduce power per output by approximately 3 dB for each doubling of outputs .
• Connectors: Common types include SC/APC, LC/UPC, and FC, with SC/APC being standard for PON networks .
• Enclosures: Splitters are often housed in ABS or LGX boxes, which can be IP65 rated for outdoor use .
• Wavelength Compatibility: PLC splitters typically support 1260–1650 nm, covering GPON, EPON, and XGS-PON standards .

Benefits

• Reduces the number of fibers required in the network, lowering deployment costs .
• Enables scalable and flexible network expansion.
• Passive operation ensures reliability and minimal maintenance. In summary, passive fiber optic LAN splitters are essential components in modern PON networks, providing efficient signal distribution, flexible deployment options, and cost-effective scalability for FTTH and enterprise LAN applications .