The linear electro-optical effect in thin oxide films*

The linear electro-optical (EO) effect, also known as the Pockels effect, has been the subject of increasing interest due to its potential for use in silicon photonic applications. As such, it is necessary to find materials that have a strong EO response in thin film form, which is essential for low power and small footprint devices. In this talk we will discuss general design rules for developing strong Pockels materials inferred from first principles theory. We will discuss the Pockels effect in BaTiO₃, strained SrTiO₃, LiB₃O₅ (LBO) and CsB₃O₅ (CBO) and use these materials as prototypical examples of where conventional wisdom breaks down. We analyze how the EO response is related to the optical phonon frequencies, Raman susceptibility and mode polarization and elucidate the underlying physical phenomena behind the large Pockels effect.