Glass computer memory could reduce cost of medical imaging

Researchers from Southampton University have created a type of glass computer memory that could reduce the costs of medical imaging.

The team, led by Prof Peter Kazansky at the university’s Optoelectronics Research Centre, used nano-structures to develop millimetre-sized devices that change the way light travels through glass.

Known as monolithic glass space-variant polarisation converters, these devices redirect the light into ’whirlpools’ that can then be read in a similar way to data in optical fibres.

Information can then be written, wiped and rewritten into the molecular structure of the glass using a laser that imprints tiny dots called voxels, which are like a 3D version of pixels in a video screen, into the glass.

‘We have improved the quality and fabrication time and we have developed this memory, which means that data can be stored on the glass and last forever,’ said researcher Martynas Beresna.

By passing polarised light through voxels imprinted in silica glass, the researchers observed that it travels differently depending on the polarisation orientation of the light.

This ’form birefringence’ phenomenon is the basis of the new polarisation converter. Using this method for microscopy could be 20 times cheaper than existing methods and much more compact.

‘Before this we had to use a spatial light modulator based on liquid crystal that cost about £20,000,’ said Kazansky. ‘Instead we have just put a tiny device into the optical beam and we get the same result.’

The technology could also be used for more precise laser material processing, optical manipulation of atom-sized objects, ultra-high-resolution imaging and, potentially, table-top particle accelerators.

The researchers are working with the Lithuanian company Altechna to introduce this technology to the market. This work was done in the framework of EU project Femtoprint.

The Optoelectronics Research Centre is also developing materials for optical fibres that are also semiconductors. These could be used for faster data streaming and more efficient solar cells.