Axial localization of luminophores by partial coherence interferometry
  We propose a solution for increasing the axial resolution of confocal microscopes. In the experimental set-up described in this paper an interference phenomenon between two counterpropagating beams is used to determine the axial position of a luminophore. The optical path difference between the two waves, which is related to the position of the luminophore, is recovered thanks to a second interferometer by using partial coherence interferometry demodulation technique. The proposed solution can find applications in biology for localizing with nanometric resolution a small number of tagged species. 
Nicolas Sandeau (IF), Herv\'e Rigneault (IF), Pierre Fran\c{c}ois   Lenne (IF), Hugues Giovannini (IF), the Mosaic Collaboration