variable optical attenuators

What is a fiber optical attenuator? Why is it used?

Fiber optic attenuators are small passive devices designed to reduce the strength of an optical signal. For those who are unfamiliar, attenuation refers to the rate at which the light or signal loses its strength. Optical attenuators are available in different types, including, fixed, step-wise variable, and continuously variable optical attenuators.

When people learn what fiber optic attenuators means, they typically wonder why anyone would want to introduce attenuation purposely on a fiber optic network. If you are also the one, then keep reading.

Why are fiber optical attenuators useful? Why do you need to accentuate signals?

There are many scenarios in which you need a mechanical variable optical attenuator. For instance, in a multi-wavelength fiber optic system, you need to equalize the strength of optical channel so that every channel has similar power levels. This requires you to reduce the strength of optical signals so that they lower down to match the channels with lower power.

Another example includes the system where received optical power is so much strong that it saturates the receiver. In this case, you will also need an optical attenuator to ensure that the receiver can detect the signal correctly.                                                                                                                                                                    

Hence, you can say that they are proved to be very useful in conditions when the signal arriving at the receiver is too strong and can overpower the receiving equipment.

But, why does a transmitter send too strong signals? This often occurs due to a mismatch between transmitters and receivers. Sometimes, it happens because the media converters are meant to be used for much longer distance than they are currently being used for.

Apart from preventing the receiver from being overwhelmed by too strong signals, optical attenuators are also widely used for stress testing a network link by reducing the signal strength incrementally until the optical link fails. It helps in determining the signal’s existing safety margin.

What are the different types of fiber optical attenuators?

While fiber optical attenuators are typically used in single-mode circuits because of the use of stronger lasers for distance transmission, you can also find multi-mode attenuators.

Male to female attenuators are the most common type of attenuators. They are also known with other names, such as plug-style or buildout style. These attenuators are designed to mount on one end of a fiber optic cable so that the cable can be plugged into the receiving equipment or panel.

There are also female to female attenuators, also called bulkhead attenuators that are often mounted in patch panels or used to connect two optic cables together.

Apart from these, there are variable optical attenuators that are highly useful for testing applications but are more expensive than other types of attenuators. Thus, before you place any order for fiber optical attenuator, you must check which type of attenuator you need and for which application.