Biomedical subjects

T Grosjean

Publications and source records attributed to T Grosjean.

3 recordsLinked to original sources

PubMed2003

Polarization filtering induced by imaging systems: effect on image structure.

In this paper are reported the results concerning the experimental study of the interaction between the vectorial amplitude of an optical field and imaging systems. It is shown that far-field as well as near-field imaging systems beside their spatial frequency filtering ability, also act as polarization filters playing a determinant role on the image structure. This conclusion is drawn from an experimental and theoretical study involving a radially polarized Bessel beam used as a test object.

Journal Article↗

PubMed2003

Bessel beams as virtual tips for near-field optics.

In the previous NFO meeting, we proposed the use of confined evanescent light beams as 'virtual' or 'immaterial' tips. Unfortunately, this technique was hindered by the need for perfectly radially polarized light beams. In this communication, we propose a simple, stable and cheap method allowing the generation of beams of any polarization and more especially of purely radially polarized light beams. We also demonstrate both theoretically and experimentally that for near-field imaging systems polarization is a limiting factor of resolution and light confinement. Finally, we present the very first experimental results dealing with virtual tips.

Journal Article↗

PubMed2001

Immaterial tip concept by light confinement.

It is shown that the combination of TM polarized coherent evanescent light beams can lead to (x, y) confined light distributions. Moreover, owing to the evanescent nature of the interfering beams, the spatial distribution of the square modulus of the electric field does not vary versus the z-distance. Such an energy distribution can be used as a virtual tip, allowing the scanning of a sample without any mechanical contact with it.

Journal Article↗