In an optical splitter, the input signal is divided among multiple output ports according to the split ratio, with each output sharing the total bandwidth of the input signal.

Split Ratios and Bandwidth Division

An optical splitter takes a single input optical signal and distributes it to multiple outputs. The split ratio defines how many outputs there are and how the input power is divided. For example, a 1:32 splitter divides one input into 32 outputs, with each output receiving roughly 1/32 of the input power if the splitter is uniform . The power per output decreases as the split ratio increases, typically by about 3 dB for every doubling of the split ratio . Although the optical power is divided, the bandwidth is shared among all connected users in a Passive Optical Network (PON). Each subscriber receives a portion of the total available bandwidth, which is dynamically allocated by the network protocols rather than being strictly proportional to the optical power . As long as the optical power at the Optical Network Terminal (ONT) is sufficient for operation, the user can access the full bandwidth assigned by the PON system.

Uniform vs Non-Uniform Splitters

• Uniform splitters distribute input power equally across all outputs, ensuring consistent signal strength and bandwidth for each subscriber .
• Non-uniform splitters can allocate more power to certain outputs, which may be used in customized network designs where some users require higher signal strength .

Splitter Architectures

The placement of splitters affects bandwidth distribution and network efficiency:

• Centralized splitting uses a single-stage splitter near the Optical Line Terminal (OLT), sending signals directly to multiple ONTs. This allows easier reconfiguration and consistent bandwidth allocation .
• Cascaded or distributed splitting uses multiple stages of splitters in series, often located in closures or pedestals. Bandwidth is still shared, but the architecture can reduce fiber usage and deployment costs while maintaining service to multiple users .

Practical Implications

• Higher split ratios (e.g., 1:64) reduce the optical power per output, which can limit reach and require careful network planning .
• Bandwidth per user is determined by the PON protocol (e.g., GPON, XGS-PON) and is shared dynamically, not strictly by optical power .
• Hybrid architectures combining centralized and distributed splitters can optimize both cost and performance while ensuring fair bandwidth distribution . In summary, the broadband of an optical splitter is shared among all outputs according to the split ratio, with network protocols managing the actual bandwidth allocation to each subscriber, while splitter placement and type influence signal strength and network efficiency .