Working Principle Of Fiber Optic Attenuators

By Author: Ryan
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In optical fiber links, the optical attenuator achieves the desired attenuation in three different principles. These are reflective principle, absorptive principle, and gap-loss principle relatively.


Reflective Principle


In an optical fiber, the scattering or reflective principle accounts for a fraction of power loss and also results from the optical fiber imperfections. But in this case, it results in scattering of the signal. In the optical fiber, the scattered light inserts interference thereby minimizing the amount of received and transmitted light. In the planned attenuation of a signal, you can employ this principle. To reflect a known quantity of the signal, the material used in the fiber optic attenuator is manufactured thus allowing only the propagation of the desired portion of the signal.


Absorptive Principle


a fraction of power loss in optical fiber is accounted for by the absorption or absorptive principle. This is because optical fiber converts it to heat after absorbing optical energy. To design an optical attenuator, the Absorptive principle ...
... can be employed with a known reduction of power. In the optical path, the absorptive principle uses the material to absorb optical energy. To reduce the power being received and transmitted, the simple principle can be an effective way. The optical switch can be bought online.


Gap-loss Principle


By inserting the device in the fiber path with an in-line configuration, power reduction is achieved with the principle of gap loss. To prevent the saturation of the receiver, Gap-loss attenuators are placed close to the transmitter. Between two optical fibers, they use a longitudinal gap so that the optical signal passed from one optical fiber to another can be minimized. The light from the transmitting optical fiber is allowed to spread out by this principle as it leaves the optical fiber. Part of the light is lost in the cladding when the light gets to the receiving optical fiber because of the spreading and a gap occurred. To ensure its effective performance these optical attenuators should be kept close to the transmitter. An optical attenuator using reflective or absorptive techniques would be more suitable to minimize the signal farther down the fiber path.


Usage of Fiber Optic Attenuators


There are generally two different situations considering when to use fiber optic attenuators in your system, where you will need fiber optic attenuators.


One is when to reduce the receiver power, fiber optic attenuators are used. There are instances when a strong signal arriving at the receiver may overpower the receiving elements. Usually, two factors determine the receiver power: how much power is lost by the attenuator and how much power is launched into the fiber. By the mismatch between the receivers or transmitters, too much receiver power can be mainly caused or the use of media converters designed for a much longer distance can cause this.


For testing the power level margins, the other one is when the optical attenuator is used. To temporarily add a calibrated amount of signal loss, the attenuators are used when testing the optic power level. In the fiber optic system, this is to test the power level margins.

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