Refractive index in ionic liquids: beyond the D line

Abstract

In the last decade, the intrinsic tunability of ionic liquids has attracted interest well beyond the disciplines that inaugurated the research on these materials at the beginning of the 1990s. One of these emerging fields is photonics, where the possibility of designing materials with task-specific optical responses is promising for a large number of potential applications. Among the optical properties of ionic liquids, refractive index has been the subject of a thorough investigation because of its relevance in the performance of most optical devices. In this chapter, we address the recent experimental and computational advances on the characterization of the refractive index of ionic liquids and the relations of this magnitude with their structure. Furthermore, we provide an important review of works introducing ionic liquids as essential optical materials in diverse applications.