Anfatec Instruments AG
Measurement Science and Technology &
Scanning Probe Microscopy

The Fiber Coupled High Speed Raman Spectrometer

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Spectrometer Performance

Raman Spectrum of Silicon Wafer

A silicon wafer can be utilized as benchmark sample for spectrometer performance. A signal to noise ratio of more than 300 could be obtained for the main silicon phonon at 520 cm-1.

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Raman spectrum of silicon measured with the Spec64 and a total exposure time of 500 ms. A 100x oil objective (1.25 NA) was utilied for light collection. The laser power at the sample was less than 4 mW at 532 nm.

Raman Imaging on Polystyrene Spheres

The Raman map of self-assebled polystyrene spheres with a diameter of 850 nm illustrates the spatial resolution of confocal Raman imaging.

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The left image shows a intensity map of the Raman spectrum of polystyrene spheres. The image size is 30 µm x 30 µm with a pixel resolution of 128 x 128. A microscope image of the measured area is displayed on the right.

Raman Mapping of Single CNTs with a Gold Tip Approached (TERS Configuration)

A highly deluted dispersion of (6,5) semiconducting CNTs was dropcoated on a glass slide. A 532 nm laser (optical power of 1 mW to 2 mW) was focussed on the apex of a full metal gold tip via the bottom objective. The distance of the oscillating tip and the sample is kept constant via the atomic force feedback (AFM) loop of the VistaScope. Laser focus and tip remains fixed while the sample is scanned.

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The 10 µm x 10 µm image shows the intensity of the G peak of CNTs. The spectra displayed on the right show a high signal to noise ratio with an acquisition time of only 100 ms.