A novel concept for a mid-field microscope

A novel concept for a mid-field microscope

Docter, M.W.
Young, I.T.
Kutchoukov, V.G.
Bossche, A.
Alkemade, P.F.A.
Garini, Y.

Applied Sciences

Imaging Science and Technology

2005-03-07

When light passes through a hole smaller than the wavelength of the light, the transmission is very low and the light is diffracted. This however changes if holes are arranged in a periodic array on metal. In that case the light couples to surface plasmons; this results in enhanced transmission, spectral selection and a small angular diffraction. We develop a novel microscopic method based on a periodic hole-array, which will be used as a multiple-apertures near-field source for illuminating a biological sample while the light is collected in far-field. The measurement speed is high, due to the use of an array instead of a single source. The main advantage of this microscope originates from the low diffraction of light through a relatively thick sample with enhanced transmission. It results in the ability to measure the samples interior and 3D reconstruction can be made by semi-confocal techniques. This overcomes the major limitation of near-field methods for which only a shallow layer of the surface (~20 nm) is detectable. For our measurements we use glass coated devices. The holes are processed with a focused ion beam. The photonplasmon coupling process is characterized as a function of the wavelength. Our experiments aim on gaining a better understanding of the transmission process. We tested the dependence of the transmitted spectrum on angle of incidence was tested as well as far-field spectral imaging measurements of the transmission in both Koehler and collimated light illumination. The results as well as the description of the microscope that we are constructing are presented.

plasmons
mid-field
nanostructure
hole array
near-field
high resolution
microscopy

http://resolver.tudelft.nl/uuid:f7b1e21d-25b0-4ba4-b59d-d50b105643ce

SPIE

0277-786X

Proceedings of SPIE, 2005 vol. 5703

Institutional Repository

conference paper

(c)2005 Docter, M.W., Young, I.T., Kutchoukov, V.G., Bossche, A., Alkemade, P.F.A., Garini, Y.