Ritesh Agarwal, professor in Materials Science and Engineering, along with lab members Stephanie Malek and Ho-Seok Ee, have a new paper in Nano Letters this month. There, they detail a new method for inducing holograms to switch between multiple images while being generated from the same source.
The technique relies on metamaterials, which are lab-made composite structures that produce unusual optical or electromagnetic effects thought he careful arrangement of their component parts.
In this case, the components were gold nanorods embedded in a stretchable plastic sheet. By carefully calculating their spacing, and the distance at which an image would appear when light was shone through the sheet, the researchers were able to embed multiple images within the same arrangement of nanorods. Stretching the plastic changes the spacing of the nanorods in such a way that multiple pre-designed holographic images are produced.