Polarization contrast in reflection near-field optical microscopy with uncoated fibre tips

Sergey I. Bozhevolnyi, Wolfgang Langbein, Jørn Märcher Hvam

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Abstract

Using cross-hatched, patterned semiconductor surfaces and round 20-nm-thick gold pads on semiconductor wafers, we investigate the imaging characteristics of a reflection near-field optical microscope with an uncoated fibre tip for different polarization configurations and light wavelengths. Is is shown that cross-polarized detection allows one to effectively suppress far-field components in the detected signal and to realise imaging of optical contrast on the sub-wavelength scale. The sensitivity window of our microscope, i.e. the scale on which near-field optical images represent mainly optical contrast is found to be ~ 100 nm for light wavelengths in the visible region. We demonstrate imaging of near-field components of a dipole field and purely dielectric contrast (related to well-width fluctuations in a semiconductor quantum well) with a spatial resolution of ~ 100 nm. The results obtained show that such a near-field technique can be used for polarization-sensitive imaging with reasonably high spatial resolution and suggest a number of applications for this technique.
Original languageEnglish
JournalJournal of Microscopy
Volume194
Issue number2-3
Pages (from-to)500-506
Publication statusPublished - 1999

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