What are the loss and isolation of the optical splitter?
The insertion loss of the optical splitter refers to the dB number of each output relative to the input optical loss. Its mathematical expression is: Ai=-10lg Pouti/Pin, where Ai refers to the insertion loss of the ith output port; Pouti is The optical power of the ith output port; Pin is the optical power value of the input port. The additional loss is defined as the DB number of the sum of the optical power of all output ports relative to the input optical power loss. It is worth mentioning that for optical fiber couplers, the additional loss is an index reflecting the quality of the device manufacturing process, reflecting the inherent loss of the device manufacturing process.

The insertion loss only represents the output power status of each output port, not only has the factor of inherent loss, but also considers the influence of the splitting ratio. Therefore, the difference in insertion loss between different fiber couplers does not reflect the quality of the device. For 1*N single-mode standard optical splitter, the additional loss is shown in the following table: the number of branches 2 3 4 5 6 7 8 9 10 11 12 16 additional loss DB 0.2 0.3 0.4 0.45 0.5 0.55 0.6 0.7 0.8 0.9 1.0 1.2.

Isolation refers to the isolation ability of a certain optical path of an optical splitter to optical signals in other optical paths. Among the above indicators, the isolation degree is more significant for the optical splitter. In practical system applications, devices with isolation degree above 40dB are often required, otherwise the performance of the entire system will be affected. In addition, the stability of the optical splitter is also an important indicator. The so-called stability means that when the external temperature changes and the working state of other devices changes, the splitting ratio and other performance indicators of the optical splitter should basically remain unchanged. In fact, the stability of the optical splitter depends entirely on the technical level of the manufacturer, and the quality of the products of different manufacturers varies greatly. In practical applications, I have indeed encountered many optical splitters with poor quality. Not only the performance indicators deteriorate rapidly, but also the damage rate is quite high. As an important component of the optical fiber trunk line, you must pay attention to it when purchasing. Price, the price of the optical branch with low technology level is definitely low. In addition, uniformity, return loss, directivity, and PDL all occupy very important positions in the performance indicators of optical splitters.