NT-MDT NTEGRA Spectra - 1.3.2. Optical Tube

Chapter 1. Basic Information
provides a wide spectral range (400 <λ < 800 nm for the laser with λ =830 nm) thus
allowing for observing the sample through the optical microscope and for optical exciting
the sample surface. High sensitivity of the detection system is due to a special design of
the laser formation system.
This measuring head is distinct in design from others in that its cantilever deflection
detection system operates with a nearly horizontal probe. For SNOM measurements, the
probe stays at low angle to horizontal (2÷3°).
Specification of the measuring head is presented in Table 1-1.
Table 1-1. Specification of the optical measuring head
Parameter
Value
Scanning type
By sample
Objective numerical aperture
0.7
Optical resolution
0.4 µm (at wavelength
550 nm)
Objective focal distance
2 mm
Visual field
~70 µm
Laser wavelength of the cantilever deflection
detection system
830 nm
650 nm
Dimensions (L×W×H)
150×130×130 mm
Weight
1.5 kg
Aperture probe
Structurally, the aperture probe is an elastic beam or cantilever (see pos. 2 in Fig. 1-6)
fixed on a silicon base (probe chip). The sensitive element of the probe is located in the
free end of the probe.
Mostly, probes of two following types are used:
− with a straight rectangular cantilever (Fig. 1-6 a);
− with a triangular cantilever formed by two beams (Fig. 1-6 b).
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