WHAT ARE FIBER OPTIC ATTENUATORS AND HOW THEY WORK?
Fiber optic attenuators are used in applications where the optical signal is too strong and needs to be reduced. For example, in a multi-wavelength fiber optic system, you need to equalize the optical channel strength so that all the channels have similar power levels. This means to reduce stronger channels’ powers to match lower power channels. Another example is when the received optical power is so strong that it saturates the receiver, you need an attenuator to reduce the power so the receiver can detect the signal correctly. This picture shows an example of a fixed optical attenuator. The attenuation level is fixed at 5 dB, which means it reduces the optical power by 5dB. This attenuator has a short piece of fiber with metal ion doping that provides the specified attenuation. There are many different mechanisms to reduce the optical power, this picture shows another mechanism used in one type of variable attenuator. Here variable means the attenuation level can be adju...