In this article, we develop a model which calculates the effects of optical
interference in polymer devices. In this model, we include the effects of
optical birefringence in the layers making up the devices, as well as the v
ariation of quantum efficiency across the active layer. We also extend the
plane wave emission modification to relate to the emission power measured o
utside the device. Experimental measurements of photoluminescence emission
from poly(p-phenylene vinylene) (PPV) devices were obtained. Comparison bet
ween the experimental and calculated angular distribution of emission is ma
de, and good agreement is found. This illustrates that the model is suffici
ent and that optical birefringence must be taken into account. Electrolumin
escence emission from poly(p-phenylene vinylene) PPV devices was also measu
red. By comparing with the calculated spectra from our model, we demonstrat
e that the model can be used as a tool to locate the position of the recomb
ination zones in electroluminescent devices. (C) 2000 American Institute of
Physics. [S0021-8979(00)04805-2].