Hello, everyone!
Today, I will continue to write about testing the IL of optical cables. In the two last articles, I explained two methods for testing IL of optical cable – single-ended and double-ended. Now, I will explain the last test method with three referent cables.
There are situations when single-ended and double-ended methods cannot be used. These are situations in which the optical cable contains optical connectors that do not match the test source, optical power meter, and referent cables. An example of such a situation is optical cables for data centers - MM optical cables with MPO/MTP optical connectors. Then, it is necessary to introduce a third reference cable. This procedure is used for both MM and SM optical cables. The measured loss is the loss that includes the attenuation of the optical fiber and the attenuation of all connector pairs.
For this method, we have to use test the source, optical power meter, and three referent cables. As with the previous two methods, a test source can be used for MM fibers (850 nm and 1300 nm) and for SM fibers (1310 nm and 1550 nm). Reference cables must be tested optical cables, with 0 dB attenuation.
Before measuring, we have to inspect and clean all optical connectors on the test source, optical power meter, and reference cables. An optical microscope and tools for cleaning optical connectors such as one-click cleaners are required.
After connecting the reference cable to the test source, it must not be disconnected during the measurement as an error will occur during the measurement.
After these procedures, we can start to measure. During and after the measurement, documentation is made which must contain the following data: date and time, name of the operator, equipment used for testing, type of setting 0 dB (reference method), type of optical cable, optical fibers, and optical connectors, test wavelength and measured loss.
This is the end of this topic. I hope you learned something new!
Thank you!
