Digital in-line holography in thick optical systems: application to visualization in pipes

Nicolas Verrier (1) , Sébastien Coëtmellec (1) , Brunel Marc (1) , Lebrun Denis (1)

1 CORIA - Complexe de recherche interprofessionnel en aérothermochimie

In this paper we apply digital in-line holography to image opaque objects through a thick plano-concave pipe. Opaque fibers and opaque particles are considered}. Analytical expression of the intensity distribution in the CCD sensor plane is derived using generalized Fresnel transform. \textbf{The proposed model has the ability to deal with various pipe shape and thickness and compensates for the lack of versatility of classical DIH models. Holograms obtained with a 12 mm thick plano-concave pipe are then reconstructed using fractional Fourier transform (FRFT).} This method allows us to get rid of astigmatism. Numerical and experimental results are presented.

Mots clés: Fourier optics and signal processing; Holography; Image processing

Domaines: Optique [physics.optics]

Nicolas Verrier, Sébastien Coëtmellec, Brunel Marc, Lebrun Denis. Digital in-line holography in thick optical systems: application to visualization in pipes. Applied optics, 2008, 47, pp.4147. ⟨10.1364/AO.47.004147⟩. ⟨hal-00767626⟩