User`s guide

What is an Attenuator? Getting Started with Attenuator Modules
Agilent 81560A, 81561A, 81566A, & 81567A Optical Attenuator Modules, First Edition 17
What is an Attenuator?
Agilent 8156xA Variable Optical Attenuators attenuate and control the
optical power of light in single-mode optical fibers. They allow you to
set the attenuation factor and/or power level manually, or via the host
instrument’s GPIB interface.
Agilent 81566A and 81567A attenuators include power control
functionality that allows you to set the output power level of the
attenuator. When power control mode is enabled, the module
automatically corrects for power changes at the input so that the
output power level set by the user is maintained. See Figure 1 on
page 17.
Installation
Agilent 8156xA Variable Optical Attenuators are front-loadable
modules for the Agilent 8163A/B Lightwave Multimeter, 8164A/B
Lightwave Measurement System, and 8166A/B Lightwave
Multichannel System, collectively referred to as ‘mainframes’.
An Agilent 81560A or 81561A module occupies one slot, while an
Agilent 81566A or 81567A module occupies two slots.
For a description of how to install your module, refer to “How to Fit
and Remove Modules” in the Installation and Maintenance chapter of
your mainframe’s User’s Guide.
Figure 1 Agilent 81566A/81567A Optical Attenuators with Power Control
attenuator
power
meter
coupler
81566A/81567A
control
loop
input output