In a translated press release, Hitachi concluded that etching data within quartz glass could store it for millions of years. Hitachi’s research was conducted in conjunction with Prof. Kiyotaka Miura of Kyoto University.
The data density is 40MB per square inch, slightly exceeding a CD’s storage density of about 35MB per square inch. Hitachi used a laser to melt dots into the surface of the quartz glass, creating an optical image roughly similar to a QR code. The 40 MB/sq. in density was achieved using four-layer recording. According to the AFP, the test “chip” of glass measured two centimeters (0.8 inches) square and two millimeters (0.08 inches) thick."
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