Fiber Optic Attenuators


Fiber optic attenuators are devices which reduce (attenuater) the strength of a fiber optic signal within a fiber optic network. It’s commonly used in fiber optic communications, either to test power level margins by temporarily adding a calibrated amount of signal loss, or installed permanently to properly match transmitter and receiver levels. Sometimes attenuators are also used for stress testing a network link by incrementally reducing the signal strength (increasing the dB attenuation) until the optical link fails, thus determining the signal existing safety margin. Sharp bends stress optic fibers and can cause losses. If a received signal is too strong a temporary fix is to wrap the cable around a pencil until the desired level of attenuation is achieved. However, such arrangements are unreliable, since the stressed fiber tends to break over time.

The most common version of attenuators are male to female units, often called plug-style or buildout style. These plug-style attenuators simply mount on one end of a fiber optic cable, allowing that cable to be plugged into the receiving equipment or panel. We also have female to female (bulkhead) attenuators, often used to mount in patch panels or for connecting two fiber optic cables together. More expensive, but useful for testing, are variable attenuatorswhich are adjustable between 1dB and 30dB. We also can custom build in-line attenuators where the attenuator is incorporated within a fiber optic patch cable, built to your specifications.

Our attenuators are a very high quality design using doped fiber to attenuate the signal. Our singlemode attenuators offer a operating wavelength range of 1250nm to 1600nm, covering both the common 1310nm and 1550nm operating wavelengths. The attenuation accuracy is +/- 0.5dB, up to 5dB and +/- 10% over 5dB. The return loss is >50dB for standard connectors and >60dB for APC connectors. Maximum transmission power is typically one watt. Although fiber optic attenuators are normally used in singlemode circuits, because this is where the stronger lasers are used for distance transmission, we also have multimode attenuators available (upon special order) in 50/125 and 62.5/125 fiber sizes. We stock attenuators for the following fiber optic connector types: ST, SC, SC/APC, FC, FC/APC, LC, LC/APC, MU. Other connector type attenuators are available upon special order. We stock most values between 1dB and 25dB for each of these attenuator types.