Abstract

Resolution of $90\mathrm{nm}$ was achieved with a research microscope simply by replacing the standard bright-field condenser with a homebuilt illumination system with a cardioid annular condenser. Diffraction gratings with $100\mathrm{nm}$ width lines as well as less than $100\mathrm{nm}$ size features of different-shaped objects were clearly visible on a calibrated microscope test slide. The resolution increase results from a known narrower diffraction pattern in coherent illumination for the annular aperture compared with the circular aperture. This explanation is supported by an excellent accord of calculated and measured diffraction patterns for a $50\mathrm{nm}$ radius disk.

© 2006 Optical Society of America

Resolution of a microscope: improvement using a centrally obstructed condenser aperture and a semitransparent Π-phase annular aperture objective system

V. P. Nayyar and N. K. Verma
Appl. Opt. 15(5) 1341-1344 (1976)

90% Extraordinary optical transmission in the visible range through annular aperture metallic arrays

Yannick Poujet, Jérôme Salvi, and Fadi Issam Baida
Opt. Lett. 32(20) 2942-2944 (2007)

Condenser for Koehler-like illumination in transmission x-ray microscopes at undulator sources

Ulrich Vogt, Magnus Lindblom, Pambos Charalambous, Burkhard Kaulich, and Thomas Wilhein
Opt. Lett. 31(10) 1465-1467 (2006)

Two-point resolution of a microscope: effect of nonuniform and nonsymmetric illumination using a semitransparent π-phase annular aperture

V. P. Nayyar and N. K. Verma
Appl. Opt. 16(9) 2460-2463 (1977)

Increasing the lateral resolution of 4Pi fluorescence microscopes

Nicolas Sandeau and Hugues Giovannini
J. Opt. Soc. Am. A 23(5) 1089-1095 (2006)