Differential near-field scanning optical microscopy.
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 mum 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.
Ozcan
Aydogan
A
Wellman Center for Photomedicine, Harvard Medical School, Boston, Massachusetts 02114, USA. aozcan@mgh.harvard.edu
Cubukcu
Ertugrul
E
Bilenca
Alberto
A
Crozier
Kenneth B
KB
Bouma
Brett E
BE
Capasso
Federico
F
Tearney
Guillermo J
GJ
D004867:Equipment Design; D019544:Equipment Failure Analysis; D020527:Microscopy, Scanning Probe / Q000295:instrumentation / Q000379:methods*; D036103:Nanotechnology / Q000295:instrumentation / Q000379:methods*; D010316:Particle Size; D012680:Sensitivity and Specificity; D013499:Surface Properties