The variable attenuator is ideal for
simulating cable loss for lab testing of link power margin or
reducing power in links where receivers are being overloaded.
The variable attenuator is of the gap-loss type. Pulling the
connector end-faces apart induces the loss. Since the light
exists in an expanding cone, the receiving fiber will capture
less light, as the gap gets larger. An air gap attenuator is
ideal for use with any LED systems and many laser systems. Some
laser systems, especially high-speed digital links (over 1 GB/s)
or analog CATV systems may not operate well with the attenuator
due to back reflections; you should use the ATT120 with a FC/APC
connector, if you use an attenuator in those types of systems.
The variable attenuator fits to cables with the connector type
shown in the specification. If you need to use the attenuator
with other connector types, use hybrid cables. The fiber type
used should also match the network fiber type, with one
exception: if in a single mode network receivers are used with a
multimode “bucket” fiber, you can use a matching multimode fiber
on the receiver side of the attenuator.