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Selected Measurements
unrivaled accuracy for different environments
Proven Sub-Nanometer Signal Stability
10
The intrinsic signal stability of the IDS – equivalent to its positional re-
peatabilty – is unheard of in position sensing. While being specified to
achieve a repeatability of 2 nm at 20 mm working distance and 100Hz mea-
surement bandwidth (in vacuum), the IDS routinely achieve significantly
better performance.
5
0
− 5
− 10
0
10
Time (h)
20 0
2
4
The actual measurement on the left shows positional stability as measured
on a titanium cavity cooled to liquid helium temperature (-269 °C), tem-
perature stabilized to few milli-degrees. The plot shows position sensing
data recorded on a 77 mm long cavity during a 20 hour period of time,
measured at 100 Hz bandwidth. The standard deviation of the above shown
measurement is 55 picometer!
6
Counts (10 )
(attocube applications labs, 2015)
Long-term signal stability as demonstrated on a 77 mm long cavity cooled to liquid helium
temperature (-269°C) in order to minimize thermal expansion/contraction.
Environmental Compensation (optional)
Any interferometric device operated in environmental conditions is negative-
ly influenced by index of refraction fluctuations, caused by air temperature,
pressure, and humidity variation. The influence of these parameters is signifi-
cant and can reach deviations in measurement of up to 500 ppm, equivalent to
a deviation of 500 μm per meter.
To compensate these errors, attocube offers an environmental compensation
unit (ECU) which precisely measures environmental parameters and deter-
mines the actual index of refraction n(t). This measurement allows to com-
pensate environmental influences down to better 1 ppm and enables highly
precise, accurate measurements in air.
(attocube application labs, 2017)
Displacement measurements as performed at variable sensor/target separation in constant
conditions. The plot shows the displacement sensing error of 246 μm over 1 meter travel range
(uncompensated) vs <1 μm (compensated).