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companies. Any rights not expressly granted herein are reserved. ATTENTION: Specifications and technical data are subject
to change without notice.
linearly extrapolated voltages.
V.2.b.
Non-Contact Mode
In non-contact mode the tip-fiber cavity has to be adjusted to the point of
highest interference sensitivity, i.e. at which the change in the tip-fiber
distance gives the biggest (linear) change in the interferometric signal.
After the cavity has been adjusted to this point, the cantilever must be
excited at its resonance frequency and the photo-detected AC voltage
AFM Aosc will be used as measuring signal for the feedback loop. The basic
steps for this procedure are sketched below.
1. Adjustment of the fiber-cantilever cavity:
Run a so-called ‘dither spectroscopy’ (spectroscopy of ADC1 vs.DAC1) to
check the interferogram. To do so, choose one of the 'Spec' windows and
enter the following settings:
DAC:
DAC1
Start:
0V
End :
max. 4V (@RT); max. 10V (@LT)
Data Points:
>1000
Data Point Avg. Time:
2-5 ms
Delay per Data Point:
0-5 ms
Choose ADC1 as the signal to be monitored.
Start the spectroscopy.
The Spectroscopy View should look similar to the figure below. The working
point WP (point of highest sensitivity where signal depends linearly on the
Содержание attoAFM I
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