User`s guide

Definition of Terms Specifications
Agilent 81560A, 81561A, 81566A, & 81567A Optical Attenuator Modules, First Edition 35
Repeatability
The uncertainty in reproducing the total loss after randomly changing
and re-setting the attenuation. The repeatability is ± half the span
between the maximum and the minimum total loss, expressed in dB.
Conditions: Uninterrupted line voltage, constant temperature,
constant humidity, constant wavelength, constant input power level,
and constant polarization state.
Measurement: with Fabry-Pérot type laser source (center wavelength
as specified ± 15nm) and optical power meter.
Resolution
The minimum addressable and displayable attenuation steps over the
whole attenuation range.
Return Loss
Minimum ratio between incident power and reflected power,
expressed in dB. Applicable to both attenuator ports, with the
respective second port terminated (zero reflectance).
Conditions: jumper cables with reference connectors on both
attenuator ports.
Measurement: with return loss meter using Fabry-Pérot type laser
source of applicable wavelength.
NOTE Measurement result includes attenuator-internal reflections,
reflections from both attenuator ports and reflection from shutter (in
case of closed shutter).
Settling Time
Maximum time needed to change the attenuation by a specified step,
from the beginning till the end of the change.
repetition
total loss [dB]
full span repeatability