Seemingly Unlimited Lifetime Data Storage in Nanostructured Glass

We demonstrate recording and retrieval of the digital document with a nearly unlimited lifetime. The recording process of multiplexed digital data was implemented by femtosecond laser nanostructuring of fused quartz. The storage allows unprecedented parameters including hundreds of terabytes per disc data capacity, thermal stability up to $1000°\mathrm{C}$, and virtually unlimited lifetime at room temperature. We anticipate that this demonstration will open a new era of eternal data archiving.

Figure 1

5D optical storage ultrafast writing setup: Femtosecond laser (FSL), Fourier lens (FL), aperture (AP) and water immersion objective (WIO) (1.2 NA). Linearly polarized (white arrows) beams with different intensity levels propagate simultaneously through each half-wave plate segment with different slow axis orientation (black arrows). The colors of the beams indicate different intensity levels.

Figure 2

Beam array multiple-level intensity control. (a) Schematic illustration of modification induced by a femtosecond laser. The colored dots indicate nanogratings induced by different intensity levels. (b)–(c) Two normalized intensity distributions calculated for two holograms from the adapted GSW algorithm. The area inside the red square is the modification region. The intensity distribution in (c) has more than 3 times the number of the multiple-level spots as compared to (b).

Figure 3

5D optical storage readout. (a) Birefringence measurement of the data record in three separate layers. (b) Enlarged $5\times 5$ dots array. (c) Retardance distribution retrieved from the top data layer. (d) Slow axis distribution retrieved from the top data layer. (e),(f) Enlarged normalized retardance matrix and slow axis matrix from (b). (g),(h) Binary data retrieved from (e),(f).

Figure 4

Arrhenius plot of the nanogratings decay rate. Black dots indicate measured values; red dots are calculated based on the fitting results. The gray shaded zone indicates the tolerance of extrapolated values. At the temperature $T=462\mathrm{K}$ nanogratings would last for the current lifetime of the Universe. (Inset) The decay of the strength of retardance with time at different annealing temperatures.