Faculté des sciences
Texte intégral

Unconventional treatment of focal shift

Vokinger, Urs ; Dändliker, René ; Blattner, Peter ; Herzig, Hans-Peter

In: Optics Communications, 1998, vol. 157, no. 1-6, p. 218-224

We present an unconventional approach for the explanation of focal shift behind a lens. It is based on the fact that, within the approximation of Fresnel diffraction, the intensity distributions in the conjugate planes of a lens are equal to their geometrical images. We show that the focus (position of highest intensity) is always shifted towards the lens. The results for a Gaussian beam and a... More

Add to personal list
    Title
    • Unconventional treatment of focal shift
    Author
    • Vokinger, Urs. Institut de Microtechnique, Université de Neuchâtel, Switzerland
    • Dändliker, René. Institut de Microtechnique, Université de Neuchâtel, Switzerland
    • Blattner, Peter. Institut de Microtechnique, Université de Neuchâtel, Switzerland
    • Herzig, Hans-Peter. Institut de Microtechnique, Université de Neuchâtel, Switzerland
    Document Type
    • Postprint
    Publication Date
    • 1998
    Classification
    • Microengineering
    OAI-PMH Identifier
    • oai:doc.rero.ch:20071217165329-PE
    Submission No.
    • 20071217165329-PE
    Summary
    We present an unconventional approach for the explanation of focal shift behind a lens. It is based on the fact that, within the approximation of Fresnel diffraction, the intensity distributions in the conjugate planes of a lens are equal to their geometrical images. We show that the focus (position of highest intensity) is always shifted towards the lens. The results for a Gaussian beam and a uniform converging spherical wave are presented.