Photorefraction from a Photochromic Soft Material

Abstract

Polydimethylsiloxane (PDMS) polymers containing photochromic ruthenium sulfoxide complexes were prepared. The absorption changes upon light exposure were recorded and changes in the index of refraction were calculated from the Kramers–Kronig relation. Four-wave mixing experiments were performed, demonstrating that an index grating can be generated. The dynamics and angular dependence of the grating were measured. We determined the holographic or photorefractive sensitivity for these materials, which is defined as volume per incident energy (cm3 J–1). We compare our materials to existing materials and discuss the factors that affect diffraction efficiency.