'Nano-glass' eyed as new computer memory

Instead of silicon-based chips, the computer memory of the future may be nano-structured glass developed by researchers at the University of Southampton. The researchers said the potential new memory, which promises to be cheaper, may also have possible applications in optical manipulation as well as medical imaging. “The advantage of this approach over existing methods for microscopy is that it is 20 times cheaper and it is compact," the university said in a news release on its website. In paper entitled “Radially polarized optical vortex converter created by femtosecond laser nanostructuring of glass published in Applied Physics Letters," a team led by Professor Peter Kazansky at the University’s Optoelectronics Research Centre described how they used nano-structures to develop new monolithic glass space-variant polarization converters. Such small devices change the way light travels through glass, generating “whirlpools" of light that can then be read in the same way as data in optical fibers. “This enables more precise laser material processing, optical manipulation of atom-sized objects, ultra-high resolution imaging and potentially, table-top particle accelerators. Information can be written, wiped and rewritten into the molecular structure of the glass using a laser," the University said. '3D pixels Also, the researchers said that at sufficient intensities, ultra-short laser pulses can be used to imprint tiny dots (like 3D pixels) called “voxels" in glass. Citing their previous research, they said lasers with fixed polarization produce voxels consisting of a periodic arrangement of ultra-thin (tens of nanometers) planes. “By passing polarized light through such a voxel imprinted in silica glass, the researchers observed that it travels differently depending on the polarization orientation of the light. This ‘form birefringence’ phenomenon is the basis of their new polarization converter," the University said. Kazansky said that before this, they had to use a spatial light modulator based on liquid crystal - which cost about £20,000 (P1.403 million). “Instead we have just put a tiny device into the optical beam and we get the same result," he said. 5-dimensional optical recording After publishing the paper last May, the researchers have improved on the technology further and adapted it for a five-dimensional optical recording. 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. “We have improved the quality and fabrication time and we have developed this five-dimensional memory, which means that data can be stored on the glass and last forever. No one has ever done this before," said Martynas Beresna, lead researcher for the project. — TJD, GMA News