A reflection-mode aperture SNOM based on external collection of the re
flected light is presented. The Light detection is based on an ellipti
cal mirror set-up, with the tip at one focus, and a PMT at the other.
Tapered metal-coated fibres are used as SNOM probes, with a wavelength
of 685 nm. Shear-force distance regulation is used. Images of a cross
grating structure indicate a shear-force resolution of 20-30 nm, and
an optical resolution of 40-50 nm (lambda/15).