Crystalline Colloidal Array Filters: Theory and Design.

Abstract

The colloidal array filter consists of an aqueous suspension of polystyrene spheres arranged in a crystalline lattice, thereby producing Bragg diffraction of incident light. Recent measurements have shown that a rejection filter incorporating a thin layer of the colloidal suspension has a moderately narrow bandwidth and unusually large peak absorbance. We have successfully explained these results using both dynamical X ray diffraction theory and optical scattering theory. The theoretical bandwidth is in good agreement with the experimental value, while the theoretical attenuation results are consistent with measured transmittance values. The theoretical attenuation function indicates that actual filters may be constructed that are thinner and more efficient than the first experimental ones. The theoretical angle shift of the rejection band maximum has also been calculated, and is in excellent agreement with experimental data. Keywords: Optical filters; dynamical X ray diffraction; Bragg diffraction; Light scattering; Rayleigh Gans theory; Colloidal crystals.

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Document Details

Document Type
Technical Report
Publication Date
Jan 01, 1987
Accession Number
ADA176646

Entities

People

  • David J. Kosan
  • Robert J. Spry

Organizations

  • Wright Laboratory

Tags

Communities of Interest

  • Air Platforms

DTIC Thesaurus Topics

  • Absorption
  • Aeronautical Laboratories
  • Air Force
  • Crystal Structure
  • Crystals
  • Dielectric Polymers
  • Diffraction
  • Government Procurement
  • Governments
  • Light Scattering
  • Materials
  • Materials Laboratories
  • Mie Scattering
  • Refractive Index
  • Scattering
  • X Rays
  • X-Ray Diffraction

Fields of Study

  • Physics

Readers

  • Materials Science and Engineering.
  • Optical Physics and Photonics.
  • Spectroscopy.