The Basics of Fiber Optic Attenuators

Fiber optics are powerful communication devices, capable of transmitting data over great distances in the form of light. While the signal power and speed of fiber optic signals is an advantage that allows for easy long distance communications, there can sometimes be instances where a signal can be too strong and requires weakening before it overloads a receiver. With devices known as fiber optic attenuators, or optical attenuators, optical signal power may be reduced in a free space or within a fiber.

Fiber optic attenuators are primarily used in fiber optic communication applications, commonly serving to either test power level margins or to match transmitter and receiver levels. While optical fibers are known for their speed and strength, having too much strength over a short distance can cause an overload condition in the fiber optic receiver. When such occurrences happen, the receiver may face high bit error rates which can be damaging to its operations. As such, it is important that signal power can be efficiently managed to ensure that it always matches safe levels for the receiver. While one could simply cause sharp bends in the assembly to create optical power losses, stress to optical fibers can lead to break downs over time, damaging system components.

The fiber optic attenuator may be inserted into the system at the receiver end, ensuring that power levels are reduced to a proper value before reaching the receiver. In general, signal power reduction can be achieved through multiple means, commonly coming in the form of absorption, diffusion, reflection, scattering, diffraction, deflection, dispersion, and more. In order to absorb excess light as signals pass through the system, attenuators will have a working wavelength of operation. Depending on one’s needs, there are a few common attenuator types, each of which present their own unique characteristics and benefits.

The fixed optical attenuator is a common type that can utilize varying working principles to manage optical power. When coming in the form of preferred attenuators, doped fibers, total power, or mis-aligned splices may be used to reduce signals. In some instances, a build out style attenuator can serve as a connection to cables, and such devices come in the form of fiber optic adapters. Lastly, the non-prefered attenuator is a type that relies on either gap loss or reflective principles, though such devices are sensitive to wavelength, vibration, contamination, temperature, and more.

With a built-in variable attenuator, manual or electrical control may be established for the means of providing a one-time set up or adaptive power optimization. While dynamic range and power feedback may be a drawback to electrically controlled devices, they avoid degradation and have optimal response speeds. Furthermore, high speed response may be achieved through the addition of liquid crystal variable attenuators or lithium niobate devices.

Variable optical test attenuators are common types that utilize a variable neutral density filter to manage signal power. While being a fairly expensive option, such attenuators are quite stable, are insensitive to wavelengths, offer large dynamic range, and are mode insensitive. Typically, such devices may be controlled manually or through motors, the latter offering users the advantage of productivity. While the variable optical test attenuator has many benefits, such devices require high amounts of calibration to function as intended.

Whether you are searching for fiber optic attenuators for a local area network or as aircraft parts, Veritable Aerospace can help you secure the fiber optic components that you need with ease. Veritable Aerospace is a leading distributor of aircraft parts and other products, offering customers competitive pricing on highly sought-after items such as patch cable fiber parts, plug connector components, fiber optic adapters, and much more. If you would like to receive a quote on items for your comparisons, we invite you to fill out and submit an Instant RFQ form as provided on our website and a dedicated account manager will reach out to you in 15 minutes or less.