Setting Attenuation and/or Power Levels Agilent 8157xA Variable Optical Attenuator modules
198 Agilent 8163A/B, 8164A/B & 8166A/B Mainframes, Sixth Edition
Agilent 8157xA Variable Optical
Attenuator modules
The Agilent 8157xA Variable Optical Attenuator family includes three attenuator
modules and two attenuator modules with power control.
The 81570A, 81571A, 81573A and 81578A single-slot modules offer a small
footprint, high resolution and low insertion loss. They also offer high power
handling and a filter technology that is wavelength flat.
The 81576A and 81577A dual-slot modules incorporate a powermeter so that you
can set the output power level of the attenuator directly. In addition, these
modules feature power control functionality, high power handling and a filter
technology that is wavelength flat.
Figure 118 shows how a signal from a photo-diode after a monitor coupler is
used as an active feedback loop.
Figure 118 81576A/77A Attenuator module power control loop
Table 13 The Agilent 8157xA Variable Optical Attenuator family
Module Description
81570A high power, single slot, straight connectors
81571A high power, single slot, angled connectors
81573A high power, single slot, SMF pigtail
81576A high power, dual slot, power control, straight connectors
81577A high power, dual slot, power control, angled connectors
81578A high power, single slot, multimode