NT-MDT NTEGRA Spectra Instruction Manual page 13

Chapter 2. Design
Fig. 2-6. SNOM measuring head
1 – output orifice for the optical fiber; 2 – leveling posts;
3 – probe holder; 4 – housing; 5 – mounting plate; 6 – motorized leveling post
All elements of the SNOM measurement head are assembled on the mounting plate 5 and
contained within the housing 4. The capacitance sensors are fixed to the bottom part of the
scanner. The end of the scanner has a special holder for the optical fiber probe 3. The top
part of the housing 4 has an output orifice 1 for the free end of the optical fiber.
There are three leveling posts to secure installation, horizontal leveling and approaching of
the probe to the sample. Two of them (pos. 2) are ordinary screws with fastening nuts. The
third post is a micrometer screw driven by a stepper motor 6 (motorized leveling post) that
provides the motorized translation of the probe towards the sample.
The probe is fixed in the holder 1 (Fig. 2-7) with spring clips 2, which also serve as
electrical contacts to acquire signal from the sensor. During installation of the sensor, the
optical fiber is pulled through the orifice 5. The scanner 3 provides scanning of the selected
XY area of the sample by the probe. It tracks the surface landscape. Observation of the
probe tip during the approach procedure or scan area selection is available through a
special groove in the protective case 4.
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