Fiber Optic Attenuators—Types And Applications

A fiber optical attenuator is a fiber-coupled device used to reduce or balance the power (the power level of an optical signal, either in free space or in an optical fiber) of the light transmitted from one device to another device. Fiber optic attenuators are designed to use with various kinds of fiber optic connectors. The basical types of optical attenuators are fixed, step-wise variable, and variable fiber optic attenuator. Insertion loss and return loss, or back reflection, are collectively referred to as attenuation; total attenuation is called system loss.

Fiber Optic Attenuators provide technicians with a means of adjusting an optical signal level. Attenuators are 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.

Commonly used fiber optic attenuators are the female to male type, which is also called a plug fiber attenuator. Plug fiber attenuators utilize male/female ceramic ferrule connectors. Fixed value attenuators function at one loss level, while variable attenuators like the variable optical attenuated jumper (VOA) can adjust loss in a range, as by a turning screw. Patch cord attenuators are fibers that combine the functions of the patch cord and attenuator, reducing costs.

Types of fiber optic attenuators:
1. Female to male plug style optical attenuator (MU, SC, FC, ST, LC) PC& APC polish available;
2. Flange style fiber optical attenuator;
3. Adjustable fiber optical attenuator (FC style) Attenuation scale:0~30dB;
4. IN-Line style fiber optical attenuator.

Wide range variable & inline fiber optic attenuator
The inline fiber optic attenuators are with more accurate attenuation compared with traditional connector type fiber optic attenuators. What is more, the fiber optic attenuator is with a precision screw set, by turing it, the attenuation range can be varied. And this fiber optical attenuator can be with various terminations on the each side of the cable.

Variable Fiber Optic Attenuators
Fixed value fiber optic attenuators can reduce the power of fiber light at a fixed value loss, for example, a 10dB SC fiber optic attenuator will reduce the optical power 10dB and utilize a SC male to female attenuator. Variable fiber optic attenuators (or adjustable fiber optic attenuator) are with adjustable attenuation range. It usually is inline type, the appearance like fiber optic patch cord; it is with an adjustable component in the middle of the device to change the attenuation level to a certain figure. There are also handheld variable fiber optic attenuators; they are used as test equipment, and we have the inline fiber optic attenuators.

Fiber optic attenuator name is based on the connector type (like lc attenuator) and the attenuation level. For example, LC 5dB fiber optic attenuator means this attenuator use LC fiber optic connector and it can reduce the optical fiber power level by 5dB. Commonly used attenuation range is from 1dB to 20Db. Fiber Optic Attenuators are employed in telecommunications networks, local area networks (LAN), and cable television (CATV) systems. They also can be used in fiber optic sensors, testing instruments, and fiber to the home. Compact, environmentally sound, and suffering low return losses, these devices can be embedded into optical fiber networks fitted to the wide variety of industry standard connectors and fibers.