Subdiffraction resolution

Klar T A and Hell S W 1999 Subdiffraction resolution in far-field fluorescence microscopy Opt. Lett. 24 954-6... 

The subdiffraction resolution is given by Ar as defined in (19.1) [39,41]. Since it is a far-held approach, the resolution still scales with A, however, it is no longer limited by A, because Imax/Is — oo leads to Ar —> 0 [39,41,69]. The reason for the square-root law is that, in hrst approximation, the intensity /(r) increases quadratically when departing from the zero-intensity point r. ... 

T. A. Klar, S.W. Hell, Subdiffraction resolution in far-held huorescence microscopy. Opt. Lett. 24(14), 954-956 (1999)... 

M. Heilemann, S. Van De Linde, M. Schiittpelz, R. Kasper, B. Seefeldt, A. Mukherjee, P. Tinnefeld, and M. Sauer, Subdiffraction-resolution fluorescence imaging with conventional fluorescent probes, Angew. Chem Int. Edit., 47,6172-6, 2008. 

Addressing molecular switches remains a problem as well. The use of diffraction-limited focused light pulses provides a useful start, but subdiffraction optical techniques need to be improved and implemented to transfer information into and out of these molecular arrays. At present near-field optical techniques are relatively slow, so that although they provide better spatial resolution, the speed of information access is somewhat limited. 

In a series of papers, these and similar measurements were used by Higgins and coworkers to characterize the response of PDLCs to changes in applied voltage. The subdiffraction limited resolution in these measurements found a spatial variation in the liquid crystal reorganization threshold that had contributions from several sources including interactions with the polymer encapsulation interface. 

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