Analysis of in-line Fresnel holograms via chirp separation


Ozgen M. T.

OPTICAL ENGINEERING, vol.45, no.3, 2006 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 45 Issue: 3
  • Publication Date: 2006
  • Doi Number: 10.1117/1.2182147
  • Journal Name: OPTICAL ENGINEERING
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Keywords: in-line Fresnel holograms, digital holography, numerical reconstruction, chirp separation, time (space)-frequency representations, time (space)-varying filtering, 2-DIMENSIONAL WAVELET TRANSFORM, COHENS BILINEAR CLASS, DIGITAL HOLOGRAPHY, RECONSTRUCTION, REPRESENTATIONS
  • Anadolu University Affiliated: Yes

Abstract

A two-step computational technique for object reconstruction from digitized in-line Fresnel holograms of particle fields is proposed that eliminates the preliminary stage of depth extraction, when the goal is recovery of only the object cross-sectional shape. The first step involves a space/spatial-frequency domain chirp separation algorithm based on a two-dimensional (2-D) separable space-varying filtering scheme to separate a hologram into its single-object components. As the second step, a recently proposed Fourier synthesis technique is applied to separated components to reveal the cross-sectional morphology of individual 2-D objects, if they are sufficiently small as compared to the hologram size. The proposed method and a modified version of it based on 1-D filtering for performance improvement are illustrated on synthesized holograms. These simulations indicate that closely spaced planar objects can be recovered without significant dispersion, and back-to-back objects can also be reconstructed with tolerable leakage if they are sufficiently apart. (c) 2006 Society of Photo-Optical Instrumentation Engineers.