Hitachi develops new storage technology save data on glass for billions of years

Hitachi and Kyoto University have jointly developed a new optical recording technology to store data on quartz glass, according to the Nikkei BP website. The most important feature of the technology is to solve the problem that the data in CD and disk, tape storage can not be saved for a long time, and record the data for billions of years.

Storage principles and test results

The technology adopts silica glass with higher purity than ordinary glass as recording medium. A small region (point) with different refractive indices is formed in the quartz glass by irradiation of a high power picosecond pulse laser. Some of the parts are recorded as "1", and the dots are "0".

The recording data is read and played using a common optical microscope. It has been confirmed that 320mbit/(inch) 2, which exceeds the recording density of the CD disc, can be burned on multiple layers.

Quartz glass heat resistance and high water resistant. In an accelerated test with 1000 ℃ heating for 2 hours, the data can still be played without aging. The experimental results show that the data can be stored for over hundreds of millions of years. Hitachi intends to commercialize the data recording service using the technology.

Hitachi has developed a technology to burn and play in quartz glass by laser in 2009. However, the surface record density was only 0.1mbit/(inches) 2, and the special method-optical tomography-was used to play it. To rotate the quartz glass plate while using the led to illuminate the visible light, reconstruct the fault image according to the multiple projection images. The development of the technology to improve the surface record density and recording speed, the use of space phase modulation technology, by changing the objective and quartz glass distance, in the 2cm square glass part of the region in 4 layers burned about 5kbit data. If the entire glass surface of 2cm square is engraved with data, the 4-tier storage capacity is about 20MB.

The technology can also be based on the point of the pattern, burning words and images. With this feature, it is possible to save the data format and playback method of the recording together with the digital data. As long as there is an optical microscope, posterity can confirm the image and text, restore the data.

(Responsible editor: The good of the Legacy)