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High-Speed Laser Writing Method Could Pack 500 Terabytes of Data into CD-Sized Glass Disc
Researchers have developed a fast and energy-efficient laser-writing method for producing high-density nanostructures in silica glass. These tiny structures can be used for long-term five-dimensional (5D) optical data storage that is more than 10,000 times denser than Blue-Ray optical disc storage technology.
[...] In Optica, Optica Publishing Group's journal for high-impact research, [Yuhao] Lei and colleagues describe their new method for writing data that encompasses two optical dimensions plus three spatial dimensions. The new approach can write at speeds of 1,000,000 voxels per second, which is equivalent to recording about 230 kilobytes of data (more than 100 pages of text) per second.
[...] The researchers used their new method to write 5 gigabytes of text data onto a silica glass disc about the size of a conventional compact disc with nearly 100% readout accuracy. Each voxel contained four bits of information, and every two voxels corresponded to a text character. With the writing density available from the method, the disc would be able to hold 500 terabytes of data. With upgrades to the system that allow parallel writing, the researchers say it should be feasible to write this amount of data in about 60 days.
5 GB / 230 KB/s = ~6 hours
500 TB / 230 KB/s = ~69 years
500 TB / 60 days = ~96.45 MB/s
Funding for the research was provided by the European Research Council (ENIGMA, 789116) and Microsoft (Project Silica).
High speed ultrafast laser anisotropic nanostructuring by energy deposition control via near-field enhancement (open, DOI: 10.1364/OPTICA.433765) (DX)
Previously: "5D" Laser-Based Polarization Vortex Storage Could Hold Hundreds of Terabytes for Billions of Years (same university, Peter G. Kazansky on both research teams)
Microsoft Stores 75.6 GB on Glass Disc Designed to Last Thousands of Years
(Score: 0) by Anonymous Coward on Wednesday November 03 2021, @12:17AM (2 children)
All these comments and zero notes of what the two added dimensions are. Polarity? Wavelength? ..?
My brain is too little to read and understand PhD level physics and pull the answer out myself.
(Score: 3, Informative) by takyon on Wednesday November 03 2021, @12:27AM (1 child)
[SIG] 10/28/2017: Soylent Upgrade v14 [soylentnews.org]
(Score: 4, Informative) by hubie on Wednesday November 03 2021, @03:56PM
As I understand the paper, three of the dimensions are the physical x-y-z location of the voxel. The other two dimensions exploit the effects you get with a birefringent material. Birefringent materials act differently upon different polarized light, so what they do is to use the lasers to create birefringence in the voxels. Prior to this work you could do that using lots of femtosecond pulses to shape/change the material properties in each voxel, but the more pulses you use per voxel, the more thermal effects you induce (and it is also slower the longer you spend at each voxel location). Other work would achieve this by using other materials to help, such as nanoparticles, to create "near field" laser enhancements. What they do in this paper is create their own near field enhancements by first inducing a microexplosion with a focused laser pulse to create a void, then use a half dozen or so other laser pulses on/near that microvoid to create an elongated structure (nanolamella) which ends up being birefringent. The physical orientation of this nanolamella determines the direction of the "slow" wave and the overall "retardation" of the light, and it is these two properties which are the other two dimensions.