EXFO PSO-100 Series Optical Sampling Oscilloscopes - Manual (Page 123)

Measurement Definitions
Optical Sampling Oscilloscope 115
Eye Width
Eye Width
The eye width is a measurement of the horizontal opening of the eye. The
eye width is defined as:
where the mean crossing points, T
cross
, and horizontal standard deviations
are measured from the histograms in the eye diagram.
EW T
cross2
3 σ
cross2
– ( ) T
cross1
3 σ
cross1
+ ( ) – =
σ
cross
cross1 cross2
Eye width
T
cross1
T
cross2