Noise and Vibration Impact on OVA Measurements

When the OVA 5000/5013/5100/5113 takes a measurement, certain parameters can be impacted by the ambient vibration (including acoustic noise) of the environment near the instrument.

High levels of vibration or acoustic noise will have a much bigger impact on phase related measurements such as CD and GD than on IL and PDL. That is because when acoustic waves or vibrations propagate through the fiber in the test path, or through the fiber inside of our instrument, those waves can modulate the optical phase of the light passing through those fibers. But vibration and acoustics don’t impact the optical power flowing through the fiber. The best way for high levels of acoustic noise to affect IL or PDL measurements would be for the noise to be high enough that a time delay domain peak would spread out so much that is difficult to know where to place the time domain filter to capture all of the peak magnitude.

As an illustration, if the lab acoustic noise is just loud enough to obscure the sound of the OVA motors and/or internal switches, then that should not be loud enough to create serious issues, and the IL and PDL dynamic range limits or accuracy levels in the specification sheets should still hold.

Keep in mind that since calibration data is subtracted off of subsequent measurements, high levels of vibration or acoustic noise can add noise to the calibration scans, which subsequently add a repeatable noise signature to subsequent measurements. If you can’t calibrate in a quiet environment, you may consider increasing the number of scans averaged together during the calibration procedure.