Photorefractive Properties of Undoped Chiral Smectic C Phases of Cyclopalladated Complexes

ABSTRACT

The photorefractive properties of chiral smectic C phases formed by cyclopalladated complexes were studied. The complexes were not doped with photosensitizers. A gain coefficient higher than 100 cm⁻¹ at an applied field of 5.4 V/µm was measured. Measurements of phase shift between interference fringes and index grating were also performed. By using a previously developed model, the amplitude of the space-charge field was estimated and shown to be much smalled than what predicted by the commonly used model for photorefractive inorganic crystals.

Keywords:

• liquid crystals
• non-linear optics
• photonics
• photorefractivity
• smectics

Acknowledgments

This work has been partially supported by MIUR under the “Molecular and Organic/Inorganic Hybrid Nanostructures for Photonics – FIRB 2001” project. P.P. thanks the Marie Curie development host fellowship contract HPMD-CT-2001–00073 for financial support.