Breaking the diffraction barrier: optical microscopy on a nanometric scale. (With commentary)

In near-field scanning optical microscopy, a light source or detector with dimensions less than the wavelength (lambda) is placed in close proximity (lambda/50) to a sample to generate images with resolution better than the diffraction limit. A near-field probe has been developed that yields a resolution of approximately 12 nm ( approximately lambda/43) and signals approximately 10(4)- to 10(6)-fold larger than those reported previously. In addition, image contrast is demonstrated to be highly polarization dependent. With these probes, near-field microscopy appears poised to fulfill its promise by combining the power of optical characterization methods with nanometric spatial resolution.

Commentary: Introduced the adiabatically tapered single mode fiber probe to near-field scanning optical microscopy which, together with shear force feedback, made the technique a practical reality. Although earlier claims of superresolution via near-field microscopy existed for nearly a decade, this paper was the first to convincingly break Abbe’s limit with visible light, as demonstrated by reproducibly resolving known, complex nanoscale patterns having features separated by much less than the wavelength. Whereas our fiber probe and shear force technologies were soon widely adopted and key to many novel applications (see above), the earlier methods proved to be technological dead ends, never achieving the results of their original claims. This experience taught me the most valuable lesson of my career: while it’s bad to bullshit others, it’s even worse to bullshit yourself. It’s a lesson sadly unheeded by many current practitioners of superresolution microscopy.

PMID: 17779440 [PubMed - indexed for MEDLINE]