Under Microscope

It's another world under the microscope.

Digital Versatile Discs or DVDs are similar to compact discs (CDs) in many ways. They employ the same encoding technology, only the density of the data is much higher for DVDs. At this scale, the pits and lands of the disc are no longer entirely clear from an optical microscope image. The width of the pits is around 400 nm rather than 800 nm as it is on regular CDs. 400 nm is too close to the wavelengths of visible light, therefore the image quality for this optical microscope observation is severely degraded. One image includes both a CD image and DVD image side by side, allowing a direct comparison of the sizes and data density. The last photo shows a lower magnification DVD image partially showing the micro scale writing on the inside edge of the disc.

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