Engineers erase and rewrite data on optical chips

"The molecules in this material are sensitive to light, so we can use a UV light or specific light wavelengths to erase or create optical components," Prof Zheng said.

The hybrid nanomaterial relies on light and molecules to draw, delete and re-write optical components. It is composed of plasmonic surface, which is made up of aluminium nanoparticles, on top of which sits a 280nm polymer layer embedded with molecules that respond to light. The molecules can either become transparent, allowing the light waves to propagate, or they can absorb the light.

To test their innovation, the researchers used a green laser to develop a waveguide on the nanomaterial. They then erased the waveguide with a UV light, and re-wrote it on the same material using the green laser. The researchers believe they are the first to rewrite a waveguide using an all-optical technique.

The innovation allows for writing, erasing and rewriting to all happen on the 2D nanomaterial – instead of requiring stand-alone optical media, light sources and detectors as is the case for DVDs and other rewritable optical components – which paves the way for nanoscale optical chips and circuits.

"To develop rewritable integrated nanophotonic circuits, one has to be able to confine light within a 2D plane, where the light can travel in the plane over a long distance and be arbitrarily controlled in terms of its propagation direction, amplitude, frequency and phase," Prof Zheng said. "Our material, which is a hybrid, makes it possible to develop rewritable integrated nanophotonic circuits."