Technologies to increase DVD capacity 4.7 GB to 1,000 Terabytes appear, what is that mechanism?
Technique for recording nine times data on conventional DVDAlthough it was, it became clear that a method to make the DVD with only 4.7 gigabyte capacity to 1,000 terabytes has appeared.
Three-dimensional deep sub-diffraction optical beam lithography with 9 nm feature size: Nature Communications: Nature Publishing Group
More data storage? Here's how to fit 1,000 terabytes on a DVD
Zongsong Gan, Yaoyu Cao, Richard A. Evans, Min Gu developed a method to increase the DVD capacity of 4.7 gigabytes to 1000 terabytes on one side of a 120 mm disc. 1000 terabytes is the amount of data equivalent to HD video for over 10 years or full HD movie for 50,000 lines.
First of all, how is digital data stored on optical discs like CD, DVD, Blu-ray Disc?
On the optical disc, you can store various data such as software, movies, games. The cost and the long life span are excellent, and the method of storing data on the optical disk is very simple. Digital data information is represented by a string represented by a binary number, and each character in a character string is called a bit. For example, when saving data to a CD, the bit is burned as a dot (groove) on the surface of the optical disc with a laser using the single beam method and it is stored as data. So the storage capacity of the optical disk depends on the physical area where the dots can be placed.
Semiconductor lasers are used to carve this dot, the size of which is determined by the wavelength of the laser.Abbe's law, The diameter of the point of light obtained by converging the light with the lens will not be less than half the visible light's 500 nanometers.
For these reasons, DVDs and Blu-ray discs are considered to be low storage density recording media.
Instead of using the single beam method, the method devised there is to break the existing limit by double beam method using beams of different colors.
First, the first beam is for activating the circular record, which is called the lighting beam (red in the image). And another donut shaped beam is a beam that suppresses the function of lighting beam (image purple).
This recording process is confined in the center of the lighting beam when the two overlap and the purple beam counterbalances the lighting beam in the donut shape. This new technology seems to be able to make an effective focus of 9 nanometers (the size of one hundred thousandth of a human hair).
This makes it possible to dramatically increase the number of dots on the disc, and furthermore, because existing optical and laser technology is used, the cost efficiency of the technology is said to be good, and if it is put into practical use, It seems that we will change society dramatically.
in Science, Posted by logu_ii