Optical fiber splitter is a device used to split and combine light wave energy.
It allocates the light energy transmitted in one optical fiber to two or more optical fibers according to a predetermined ratio, or combines the light energy transmitted in multiple optical fibers into one optical fiber.
(1) Insertion loss.
The insertion loss of an optical fiber splitter refers to the dB loss of each output relative to the input light. Its mathematical expression is: Ai=-10lg Pouti/Pin, where Ai refers to the i-th output port Insertion loss; Pouti is the optical power of the i-th output port; Pin is the optical power value of the input end.
(2) Additional loss.
Additional loss is defined as the DB number of the total optical power of all output ports relative to the input optical power loss.
It is worth mentioning that for optical fiber couplers, additional loss is an indicator of the quality of the device manufacturing process. It reflects the inherent loss of the device manufacturing process. The smaller this loss, the better, which is a sign of superior manufacturing quality. Poor assessment indicators.
The insertion loss only represents the output power status of each output port, not only the inherent loss factor, but also the influence of the splitting ratio.
Therefore, the difference in insertion loss between different optical fiber couplers does not reflect the quality of device manufacturing.
For the 1*N single-mode standard optical fiber splitter, the additional loss is as shown in the following table: Number of splitters 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
(3) Split ratio.
The splitting ratio is defined as the output power ratio of each output port of the optical fiber splitter. In system applications, the splitting ratio is indeed determined based on the optical power required by the actual system optical node to determine the appropriate splitting ratio (average Except for distribution), the splitting ratio of the fiber optic splitter is related to the wavelength of the transmitted light. For example, when an optical splitter transmits 1.31 μm light, the splitting ratio of the two output ends is 50:50; when transmitting 1.5 μm light, Then it becomes 70:30 (the reason why this happens is that optical fiber splitters have a certain bandwidth, that is, the frequency bandwidth of the transmitted optical signal when the splitting ratio is basically unchanged).
So when ordering an optical fiber splitter, the wavelength must be specified.
(4) Isolation.
Isolation refers to the ability of a certain optical path of an optical fiber splitter to isolate optical signals from other optical paths.
Among the above indicators, isolation is of greater significance to optical fiber splitters. In actual system applications, devices with an isolation of more than 40dB are often required, otherwise the performance of the entire system will be affected.
In addition, the stability of the optical fiber splitter is also an important indicator. The so-called stability refers to the splitting ratio and other performance indicators of the optical fiber splitter when the external temperature changes and the working status of other devices changes. should remain basically unchanged. In fact, the stability of the optical fiber splitter completely depends on the workmanship of the manufacturer.Depending on the level of technology, the quality of products from different manufacturers varies greatly.
In practical applications, I have indeed encountered many low-quality fiber optic splitters. Not only do their performance indicators deteriorate quickly, but their damage rates are quite high. As important components used in fiber optic trunk lines, when purchasing Be sure to pay attention. You cannot just look at the price. The price of an optical splitter with a low level of craftsmanship will definitely be low.
In addition, uniformity, return loss, directivity, and PDL all occupy a very important position in the performance indicators of fiber optic splitters.
