Differential near-field scanning optical microscopy


Aydogan Ozcan, Ertugrul Cubukcu, Alberto Bilenca, Kenneth B. Crozier, Brett E. Bouma, Federico Capasso, and Guillermo J. Tearney. 2006. “Differential near-field scanning optical microscopy.” Nano Letters, 6, 11, Pp. 2609-2616.
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We theoretically and experimentally illustrate a new apertured near-field scanning optical microscopy (NSOM) technique, termed differential NSOM (DNSOM). It involves scanning a relatively large (e.g., 0.3-2 mu m wide) rectangular aperture (or a detector) in the near-field of an object and recording detected power as a function of the scanning position. The image reconstruction is achieved by taking a two-dimensional derivative of the recorded power map. Unlike conventional apertured NSOM, the size of the rectangular aperture/detector does not determine the resolution in DNSOM; instead, the resolution is practically determined by the sharpness of the corners of the rectangular aperture/detector. Principles of DNSOM can also be extended to other aperture/detector geometries such as triangles and parallelograms.
Last updated on 05/29/2020