Optical splitters at both ends of the optical fiber

Optical splitters are generally used within the distribution network, not at both ends of an optical fiber. Optical splitters are passive devices that divide a single optical signal into multiple outputs or combine multiple signals into one, enabling efficient sharing of a single fiber among multiple users in networks like FTTH and PON. They operate without power, relying on the physics of light to distribute signals, and are essential for cost-effective network deployment.

Placement in the NetworkIn a typical FTTH setup, the Optical Line Terminal (OLT) at the central office generates the optical signal, which travels through the fiber to the optical splitter located in the Optical Distribution Network (ODN). The splitter then distributes the signal to multiple Optical Network Units (ONUs) at the user end. This means splitters are positioned between the OLT and ONUs, not at both ends of the fiber.

The splitters can be deployed in two main architectures: Centralized splitting: A single splitter in a distribution box connects one fiber from the OLT to multiple ONUs, commonly using ratios like 1: 32 or 1: 64. Cascaded splitting: Two stages of splitters are used, where a primary splitter divides the signal first, and secondary splitters further distribute it to end users, typically with ratios like 1: 4 or 1: 8 for the primary and 1: 8 or 1: 16 for the secondary.

Functionality

Splitters are bidirectional in many cases, meaning they can handle signals traveling in both directions, which is important for two-way communication such as video calls or data transmission. However, the active components—the OLT and ONU—are located at the ends of the fiber, while the splitter itself is in the middle to manage distribution efficiently. Types of SplittersFBT (Fused Biconical Taper) splitters: Suitable for small splits (1: 2, 1: 4), adjustable, but sensitive to wavelength and temperature.

PL

C (Planar Lightwave Circuit) splitters: Ideal for larger splits (1: 32, 1: 64), offering uniform output and low insertion loss, commonly used in modern PON networks. In summary, optical splitters are not installed at both ends of a fiber; they are strategically placed within the distribution network to divide signals from the OLT to multiple ONUs, optimizing fiber usage and network scalability.