Suppressed angular color dispersion in planar microcavities

We report an improved microcavity design which allows the suppression of the viewing angle dependence of the color emitted by a planar device. This is demonstrated for luminescent conjugated polymer based cavities, for which the wavelength change is reduced from similar to 60 to 10 nm at an angle of 60 degrees. We introduce the concept of cavity optical length dispersion and suggest structures for which the wavelength change with viewing angle is reduced to 5 nm at a viewing angle of 60 degrees irrespective of the emissive material. (C) 1997 American Institute of Physics.