I am trying to find out liquids that would change their refractive index with applied electromagnetic field. Do they exist? I cannot seem to find a lot of research on it.
A super basic example is water with salt and when EM field applied change of ion positions in the water result in a refractive index change. Probably this is a bad example but I am looking for good ones. Particularly, I am wondering why people didn't implement liquid lenses that can change their index in a matter of nSecs.