Fiber optic attenuators are used in network applications where the optical signal is too strong and needs to be reduced. There are many applications where this occurs, such as the need to equalize the channel strength in a multi-wavelength system or reduce the signal level to meet the input specification of an optical receiver. In both cases, the optical signal strength must be reduced or it may cause system performance issues.
Types of Fiber Attenuators
Optical attenuators can take many forms, but the two basic types of fiber attenuators are fixed and variable. In this article, we'll focus on fixed types.
Fixed attenuator
A further classification of fixed attenuators is
1. Optical fiber male and female attenuator
Optical fiber male and female attenuators
2. In-line jumper
jumper
The built-in attenuator measures approximately 1.25 inches. Many products have a male interface connector on one end and a female interface connector on the other, but there are also female-to-female interface connectors. Fabrication of extended patterns is typically done using air gap attenuation or doped fiber attenuation.
What is an air gap attenuator?
The air gap attenuator achieves the loss of optical power by means of two optical fibers separated by air. These attenuators can be fixed or variable, but the disadvantage is that they can be susceptible to dust contamination and are also susceptible to changes in temperature and humidity. Care must also be taken where they are used. For example, like the multi-channel analog systems used by CATV, this attenuator creates second-order distortion, which reduces system performance.
What is a doped fiber attenuator?
As the name suggests, doped fiber attenuators consist of a short length of fiber and a metal ion dopant that provides precise attenuation as well as an interface between the attenuator's male and female connections. These types can be wavelength sensitive due to their manufacture. The main reasons for preferring these doped fiber attenuators include:
1. Not easily affected by dust, moisture or temperature changes
2. Provides stable performance under wide wavelength variation and bandpass conditions.
