The photonic integration of non-solid media using optofluidics

Photonics has long been used to study non-solid materials such as liquids, gases and plasmas, but these fluidic media have traditionally not comprised a functional part of the photonic device or system. The emerging field of optofluidics seeks to create new ways of uniting solid and non-solid materials in a single photonic system whose optical properties are typically defined by the fluidic component. This Review summarizes the current state of optofluidics from a photonics perspective. First, we describe a new class of photonic elements based on the combination of fluidic media and integrated optical structures. We then discuss the applications of optofluidic principles to particle sensing and manipulation in fluids, and finally assess current challenges and potential directions for future developments.