Photodefinable electro-optic polymer for high-speed modulators

Abstract
Direct waveguide definition of a negative photoresist (SU8) containing tricyanovinylidenediphenylaminobenzene (TCVDPA) as electro-optic (EO) chromophore, has been demonstrated for the first time. This was possible by utilising the chromophore low absorption window in the UV region allowing crosslinking of the host polymer by exposing to UV light followed by thermal curing. TCVDPA was modified by attachment of bulky side groups. This reduced the intermolecular interactions and resulted in an increased EO (r33) coefficient.