Light emitted from the aperture of a near-field optical probe in the close vicinity of a dielectric object propagates in classically `forbidden' as well as `allowed' directions; the two zones are separated by the critical angle for total internal reflection. The new `tunnel' near-field optical microscopy (TNOM) technique makes use of forbidden and allowed radiation, in contrast to standard scanning near-field optical microscopy (SNOM or NSOM), which records only the allowed light. Scan images obtained with allowed and forbidden light are complementary to some extent; the latter, however, provide high contrast and resolution even in situations in which standard SNOM/NSOM shows little or no contrast. The influence of topography on image formation is analyzed and discussed.

Date Published: 6 September 1995
PDF: 8 pages
Proc. SPIE 2535, Near-Field Optics, (6 September 1995); doi: 10.1117/12.218689

Published in SPIE Proceedings Vol. 2535:
Near-Field Optics
Michael A. Paesler; Patrick J. Moyer, Editor(s)