|
-A
small area
(7mm) of a
hard-disk
platter was
tested using
the Zygo
GPI xp HR
(high
resolution)
interferometer
-The same
area was
tested with
our standard
instrument
Optino/Sensoft
-Both the
tests were
done in
double pass
at 632.8nm
-A high
quality
lambda/20
flat mirror
was used for
the
calibration
|
Measured
parameters
Parameter
|
Zygo
GPIxp
HR
|
Optino
Pro
|
Difference
|
|
P-V
(nm)
|
93.2
|
100.2
|
7
|
|
Rms
(nm)
|
18.3
|
20.3
|
2
|
|
Defocus
(nm)
|
-23.2
|
-19.9
|
-3.3
|
|
P-V
(waves)
|
0.1473
|
0.1596
|
0.011
|
|
Results
|
 |
|
|
|
|
3D Surface
plot from
Zygo |
3D surface
plot from
Optino |
|
|
|
|