Structure of Solidified Colloidal Array Laser Filters Studied by Cryogenic Transmission Electron Microscopy
Eduardo A. Kamenetzky 1,
Lino G. Magliocco 1, and
Hans P. Panzer 1
1 CYTEC Research and Development, 1937 West Main Street, P.O. Box 60, Stamford, CT 06904
Ordered arrays of charged uniform colloidal polystyrene particles in solution form a single-wavelength laser filter that is transparent to other wavelengths. A usable filter was prepared by solidification within an acrylamide—methylene-bisacrylamide gel. The rejection wavelength of the colloidal array filter changes with gel composition. Cryogenic transmission electron microscopy of two gel formulations shows that the colloidal array filter is composed of AAA stacking of close-packed planes. Excellent agreement is found between the layer spacings measured and those predicted from the rejection wavelengths.
Submitted on July 13, 1993
Accepted on November 15, 1993
