PLC optical splitter technical indicators

1. Insertion Loss

The insertion loss of the optical splitter refers to the number of dB of each output relative to the input light loss. The mathematical expression is: Ai=-10lg Pouti/Pin, where Ai is the insertion loss of the ith output port; Pouti is The optical power of the ith output port; Pin is the optical power value at the input.

2. Additional Loss

The additional loss is defined as the number of DBs of the total optical power of all output ports relative to the loss of input optical power. It is worth mentioning that for fiber couplers, the additional loss is an indicator of the quality of the device manufacturing process, reflecting the inherent loss of the device manufacturing process. The smaller the loss, the better, which is the evaluation index of the quality of the production. The insertion loss only indicates the output power status of each output port, which not only has the inherent loss factor, but also considers the influence of the split ratio. Therefore, the difference in insertion loss between different fiber couplers does not reflect the quality of the device fabrication.

3. The Split Ratio

The splitting ratio is defined as the ratio of the output power of each output port of the optical splitter. In system applications, the split ratio is determined by the amount of optical power required by the actual system optical node to determine the appropriate split ratio (except for the average allocation). The splitting ratio of the optical splitter is related to the wavelength of the transmitted light. For example, when one optical branch transmits 1.31 micron light, the split ratio of the two outputs is 50:50; when transmitting 1.5 μm, it becomes 70: 30 (The reason for this is that the optical splitter has a certain bandwidth, that is, the bandwidth of the optical signal transmitted when the splitting ratio is substantially constant). Therefore, be sure to specify the wavelength when ordering the optical splitter.