InPhase Technologies claims to have broken the record for the highest data density of any commercial storage technology after successfully recording 515Gb of data per square inch.

Holographic storage can dramatically boost capacity as it takes advantage of volumetric efficiencies rather than recording only on the surface of the material.

Densities in holography are achieved by different factors to magnetic storage. Density depends on the number of pixels/bits in a page of data, the number of pages stored in a particular volumetric location, the dynamic range of the recording material, the thickness of the material, and the wavelength of the recording laser.

In this demonstration there were over 1.3 million bits per data page, and 320 data pages spaced 0.067 degrees apart were stored in the same volume of material.

A collection of data pages is referred to as a 'book', and InPhase's PolyTopic recording architecture enables more holograms to be stored in the same volume of material by overlapping not only pages, but books.

Three tracks of overlapping books were written with a track pitch of 700 microns. The InPhase Tapestry material was 1.5mm thick, and the laser wavelength was 407 nanometres.

"IT professionals are experiencing enormous growth in their data archives," said Wolfgang Schlichting, research director for removable storage at IDC.

"InPhase Technologies' announcement is an important milestone in storage density, demonstrating the impressive capacity increases enabled by holographic storage. The technology represents a potential alternative to incumbent technologies for archival storage requirements."

InPhase promised to begin shipping the first holographic drive and media later this year.

The first generation drive has a capacity of 300GB on a single disk with a 20Mbps transfer rate. The first product will be followed by a family ranging from 800GB to 1.6TB capacity.

"The latest results from our ongoing tests on holographic data density have surpassed expectations," said Kevin Curtis, chief technology officer at InPhase.

"We are particularly pleased at the rate of improvement. In April 2005 we demonstrated 200 Gb/in data density and a year later the density has increased more than 2.5 times."