The influence of spatial frequency in partial spatial erasure of holographic diffraction gratings within LiNbO3 : Fe

Ince R., Yukselici H., Ince A. T., Tunc A. V.

OPTICS AND LASERS IN ENGINEERING, cilt.46, sa.11, ss.842-847, 2008 (SCI-Expanded) identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 46 Sayı: 11
  • Basım Tarihi: 2008
  • Doi Numarası: 10.1016/j.optlaseng.2008.05.021
  • Dergi Adı: OPTICS AND LASERS IN ENGINEERING
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Sayfa Sayıları: ss.842-847
  • Yıldız Teknik Üniversitesi Adresli: Evet

Özet

The effect of spatial frequency on partial spatial erasure of a hologram within a photorefractive crystal, lightly doped LiNbO3, was studied by capturing its reconstructed image on a digital camera at times varying from 40s to 420 min after storage. The image's constituent spatial frequencies (6.2-62.3/cm) at these times were studied. Using a capacitor discharge model, lower spatial frequencies (6.2-41.6/cm) discharge exponentially after 180 min, the maximum space-charge field was found to occur for a median spatial frequency of 34.6/cm. Higher spatial frequencies charge continuously. Features oscillating at similar to 2 mu m/s were superimposed on all frequencies >27.7/cm, evolving quadratically to a maximum amplitude at the spatial frequency of 48.5/cm before decaying. It is thought that the refractive-index field stored within the photorefractive crystal caused focussing of the read-out beam leading to the generation of a spatial soliton. (C) 2008 Elsevier Ltd. All rights reserved.