Multi coloured holograms could enhance optical storage
1 min read
Researchers from the University of Cambridge have developed a method for making multi coloured holograms from a thin film of silver nanoparticles. The approach is said by the team to have the potential to 'greatly increase' the capacity of typical optical storage devices.
The work is based on the fact that nanoscale metallic particles display iridescent colours; an optical phenomenon known as dichroism.
Although the phenomenon has been known for centuries, scientists have only begun to understand this phenomenon recently.
"This technology will lead to a new range of applications in the area of photonics, as conventional optical components simply cannot achieve this kind of functionality," said Yunuen Montelongo, a PhD student from the Department of Engineering, who led the research. "The potential of this technology will be realised when they are mass produced and integrated into the next generation of ultra thin consumer electronics."
Using a single thin layer of silver, the team patterned colourful holograms containing 16million nanoparticles per square millimetre. Each nanoparticle scatters light into different colours, depending on its size and shape. The scattered light from each nanoparticle interacts with that from the others to produce an image.
The device can also display different images when illuminated with a different colour light, a property not seen before in a device of this type. And when multiple light sources are shone simultaneously, a multicolour image is projected.
Currently, the team is exploring various optical mechanisms involved in the light-matter interaction at nanoscale. The future research will involve the construction of 3D dynamic displays for consumer electronics and the researchers are already looking into tuning these devices for reconfigurable display technologies.
