Boffins in the UK’s Southampton University have devised a five-dimensional storage scheme using glass, femtolasers and a lifespan of billions of years, so they say.
Researchers, led by Martynas Beresna, in the university’s Optoelectronics Research Centre (ORC) have built five-dimensional photonic structures in nano-structured fuzed quartz glass with femtosecond pulses of light; meaning one quadrillionth (one millionth of one billionth) of a second.
Data is written in three layers of nano-structured dots, voxels, separated by five micrometres (one millionth of a metre).
A voxel is an optical vortex, a polarisation vortex using nano-gratings, and a paper by the researchers, “Radially polarized optical vortex converter created by femtosecond laser nanostructuring of glass”, explains how they:
...demonstrate a polarization vortex converter, which produces radially or azimuthally polarized visible vortices from a circularly polarized beam, using femtosecond laser imprinting of space-variant self-assembled form birefringence in silica glass.
When the femtolaser pulse hits the glass it causes polarisation vortices to be created which change the way light passes through the glass, modifying its polarisation. This polarisation can be detected using a combined optical microscope and polariser.
The dimensions of the three-layered nano-structured dot voxel are length, width, depth, size and orientation.
We’re told an optical disk, using this technology, could hold 360TB of data for 13.8 billion years at 190oC, meaning a virtually unlimited lifetime at room temperature.
Data can be written, erased and rewritten, and the prospect of a lifespan in billions of years for storage in a glass medium impervious to water could be attractive to archiving use cases.
Altechna, a Lithuanian laser optics company, is working on commercialising the technology.
The researchers are presenting their research as a paper; “5D Data Storage by Ultrafast Laser Writing in Glass” at The International Society for Optical Engineering Conference in San Francisco, USA, on Wednesday 17 February. ®