Scanning probe microscopy (SPM) traditionally employs a sharp tip as a sensor. This geometry is a problem for many modern near-field probes, such as NV centers in diamond, which cannot easily be placed on a tip.
Here we present a novel, tipless approach - a technique to scan a planar probe parallel to a planar sample at a distance of few tens of nanometers.
The core of our scheme are optical far-field techniques to measure both distance and tilt between the probe and the sample with sub-nm and sub-mrad precision. These measurements are employed as a feedback signal for positioning.
Using this scheme, we demonstrate scanning near-field optical microscopy (SNOM) of plasmonic modes in silver nanowires using shallow NV centers in a bulk diamond. We will equally present ongoing experiments to implement a scanning nanogap cavity.
S. Ernst et al., ACS Photonics 6, 327 (2019)
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