Guide To Fiber Optic Attenuator

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Fiber
Optic Attenuator is a device to reduce the optical fiber power at a certain
level by a predetermined factor. The intensity of the signal is described in
decibels (dB) over a specific distance the signal travels. Attenuator provides
a certain amount of isolation between instruments, thus reducing measurement
interaction. This can be done by attenuating the unwanted reflected signal due
to imperfect matching. Fiber optic attenuators are used in applications where
the optical signal is too strong and needs to be reduced, it is mainly used for
fiber optic system of measurement, signal attenuation for short distance
communication system and system test, etc. For example, in a multi-wavelength
fiber optic system, you need to equalize the optical channel strength so that
all the channels have similar power levels. This means to reduce stronger
channels’ powers to match lower power channels.

 

The basic types of optical attenuators are
fixed and Variable Attenuators. The most commonly used type is female to male
plug type fiber optic attenuator, it has the fiber connector at one side and
the other side is a female type fiber optic adapter. Female to male mechanical
attenuator is assembled with a fixed type connector, so it can only be
connected with one patch cord, such as LC Attenuator, sc Attenuator, fc
Attenuator, st Attenuator, etc.

 

Fixed Attenuators

 

Fixed value attenuators have fixed values
that are specified in decibels. Just its name implies, fixed value attenuator’s
attenuation value cannot be varied. The attenuation is expressed in dB. The
operating wavelength for optic attenuators should be specified for the rated
attenuation, because optic attenuation of a material varies with wavelength.
Their applications consist of telecommunication networks, optic fiber test
facility, Local Area Network(Lan) and Catv systems.

 

Fixed value attenuators are composed of two
big groups: In-line type and connector type. In-line type looks like a plain
fiber patch cable; it has a fiber cable terminated with two connectors which
you can specify types. The in-line fiber optic attenuator is fit to use with
optical patch cables. To use these in-line Fiber Optics Attenuators just select
the connector type you need ST, SC, LC, & FC Available, the Polish (PC, UPC
or APC angled Polish) & the Decibel dB rating.

 

Variable Attenuators

 

Variable attenuators come with variety
separate designs. They are normal used for testing and measurement, but they
also have a wide usage in Edfas for equalizing the light power among separate
channels. One type of changeable attenuator is built on a D-shaped fiber as a
type of evanescent field device. If a bulk external material, whose refractive
index is greater than the mode effective index, replaces a part of the
evanescent field reachable cladding, the mode can come to be leaky and some of
the optic power can be radiated. If the index of the external material can be
changed with a controllable mean, straight through the effects such as
thermo-optic, electro-optic, or acoustic-optic, a gadget with controllable
attenuation is achievable. Other types of variable attenuators consist of air
gap, clip-on, 3-step and more.

 

As it comes to getting a fiber optic
attenuator you have several options listed above, so before you buy one you
must be sure at what level you want to attenuate your signal and then choose
what type will work best for you. Taking the time to choose the right one can
save you big time.