What is Fiber Optical Splitter?Which Parameters Affect Its Function

The optical splitter is one of the important passive devices in the optical fiber link. It is generally used in the optical line terminal OLT and the optical network terminal ONU of the passive optical network to realize the optical signal splitting.
The optical splitter distributes the transmitted optical signal in one optical fiber to multiple optical fibers.
There are many types of distribution, 1 × 2, 1 × 4, 1 × N, or 2 × 4, M × N. For FTTH, The general architecture in FTTH: OLT (computer room office end)-ODN (passive optical network distribution system)-ONU (user end), in which the optical splitter is applied in ODN to realize that multiple end users sharing a PON interface. In the PON structure, when buildings scattered and irregular ,low density, far distance like the villas, the centralized splitting method can make full use of resources and cover the surrounding. Only one optical splitter or multiple optical splitters may be used together to split optical signals may be used in a passive optical network.
The optical splitter performance indicators are as follow

1.Insertion loss
the insertion loss of the fiber splitter refers to the number of dB of each output relative to the input optical loss. The smaller the insertion loss value, the fiber splitter quality is better

2. Split ratio
The split ratio is defined as the output power ratio of each output port of the fiber splitter. Generally, the splitting ratio of the PLC optical splitter is evenly distributed, and the splitting ratio of the fused tapered optical splitter(FBT Splitter) can be unequal. The splitting ratio setting is related to the wavelength of the transmitted light. For example, when an optical branch transmits 1.31 micron light, the splitting ratio of the two output ends is 50:50; when transmitting 1.5 μm light, it becomes It is 70:30 (the reason why this occurs because the fiber splitter has a certain bandwidth, that is, the bandwidth of the optical signal transmitted when the split ratio is basically unchanged).

3. Isolation
Isolation refers to the one optical path signal isolation capability of splitter from optical signals in other optical paths.

4. Return loss
Return loss, also called reflection loss, refers to the power loss of the optical signal returned or reflected by the discontinuity in the fiber or transmission line. The greater the return loss, the better, to reduce the impact of reflected light on the light source and system.
In addition, uniformity, directivity, PDL polarization loss, etc. are also parameters that affect the performance of the optical splitter. Optical fiber splitter is one of the most important passive devices in the optical fiber link. It is especially suitable for connecting MDF and terminal equipment in passive optical networks (EPON, GPON, BPON, FTTX, FTTH, etc.) to distribute optical signals.