AN-125 Bend-Insensitive Multimode Fiber (BIMMF)

Overview

It is no secret that when standard optical fiber is bent, twisted, or otherwise contorted, it will exhibit increased loss. Until recently it was an accepted fact that in certain situations, such as in patch panels, cabinets, enclosures, and other places where space is limited or sharp corners or bends exist, there was a trade-off between how small these spaces could be and how long the cables would have to be without significant bend loss due to bending, twisting, or stretching. In 2009, however, a more durable, stress-resistant type of multimode cable was developed and it is revolutionizing fiber optics by allowing enclosures, patch-cabinets, and other types of cable hubs to be designed much more compact than was previously possible without introducing loss.

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AN-114 RL Testing for APC Terminated Cables

Overview

When referencing return loss, the OP930 scans a length of fiber and looks for a large reflection (~14dB or a 4% reflection). However, a reference cable that has an APC endface will not give a reflection large enough to trigger the OP930 to reference. To fix this issue and to be able to measure DUTs with APC endfaces, two methods will be discussed below that will allow the OP930 to perform a proper reference measurement.

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AN-103 Measuring ILRL

Overview

Testing hybrid cables poses certain difficulties due to the ends having unlike connector types. Typically hybrid bulkheads/adapters are required (SC-FC, ST-FC, etc.) and many times they solve the problem with minor issues. However, in some circumstances hybrid bulkheads will not suffice.

When testing SC-LC cables, such an instance arises. SC-LC bulkheads have high loss and poor repeatability and as such, they should not be used in the testing process. To get around this issue, the golden cable method can be used.

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