近年、電気光学ポリマーは超高速光変調器や光スイッチなど様々な応用が期待されている。熱及び化学的な安定性に優れた大きな超分極率を持った電気光学色素が開発され、電気光学定数r33が100 pm/Vを超える電気光学ポリマーに関する報告がなされてきている。電気光学定数r33を評価する方法は幾つかあるが、測定方法が比較的単純で、その測定のための試料準備が簡易であることから、反射型のエリプソメトリー法が多くの研究で用いられてきている。一方、この測定法は注意深く実験を行わなければ人為的、原理的な測定誤差が生じやすいなどの欠点が指摘されてきている。本研究では、電気光学ポリマーの電気光学定数r33の評価のための簡便で信頼性のあるアパチャーなしの透過型エリプソメトリーの開発を行った。

Recently, considerable attention has been paid to the development of polymeric electro-optic (EO) materials due to their potential applications in ultra-high-speed optical modulators and switches, digital signal processing, and electric-field sensors. The EO polymers with a large EO coefficient r33 over 100 pm/V have been developed by using EO chromophores with large molecular first hyperpolarizability and excellent thermal and chemical stability. Several techniques for characterizing EO performance have been developed. Among these methods, the reflection ellipsometric method has been most commonly used due to the simplicity of its measurement procedure and its sample preparation. On the other hand, some drawbacks of this method are pointed out both from practical and intrinsic viewpoints. Without greater care, the obtained data by this method can lead to inaccurate results. In this paper, we have developed the transmission ellipsometric method without an aperture for simple and reliable evaluation of the EO coefficient r33 of EO polymers.