Evaluation of Optical Characteristics in Electro‐Optic Chromophores Designed for Applications at O‐Band

Abstract

Herein, lots of electro‐optic (EO) chromophores designed for applications at O‐band are synthesized, and the first hyperpolarizability β of EO chromophores is evaluated by the hyper‐Rayleigh scattering (HRS) technique. EO chromophores are constituted of various tricyanofuran (TCF) derivatives as the electron acceptor unit, thienyl‐di‐vinylene or thienyl‐di‐vinylene with ethylenedioxy as the π‐conjugation unit, and aminobenzene with a benzyloxy group as the donor unit. Halogen phenyl group or trifluoromethyl‐phenyl group in TCF acceptor unit leads to a relatively large improvement in β values. Furthermore, EO polymers with some promising EO chromophores that are suitable for the applications at O‐band (1260–1360 nm) are synthesized, and EO coefficient r33 (or n3r33) and absorption loss α are evaluated. Considering the trade‐off relationship between r33 (or n3r33) and α, EO polymers with excellent EO chromophores in the C‐band (1530–1565 nm) are not necessarily suitable EO polymers in the O‐band (1260–1360 nm). EO polymers with the O‐band chromophores have small α and moderate r33 (or n3r33) at the O‐band, while EO polymers with the C‐band chromophores have large α and slightly modified r33 (or n3r33) at the O‐band. The development of suitable EO chromophores and polymers for O‐band and C‐band respectively is very important.