Holographic recording in a series of conjugated polymers

We present the efficiency of holographic recording in a series of conjugated polymers of the polyphenylenevinylene type and correlate the results with the molecular structure. Diffraction gratings were recorded at three different wavelengths in order to distinguish between the effects of absorbance and molecular structure. It is found that polymer films with pure alkyl chains do not give rise to high diffraction efficiency. Thick films of most of the materials were found to yield a diffraction efficiency on the order of 5%, with MEH-PPV film gives a diffraction efficiency exceeding 25%. Atomic force microscope scans of the gratings show that a surface relief grating is also produced. The gratings were found to be stable for more than one year, when they are kept in the dark.