Next generation media "Holographic Drive" of 300 GB in 1 inch appeared this year

By the way, in the future it seems that 515 GB per square inch will fit.
It is not "megabyte" but "gigabyte".
DailyTech - First Holographic Drives and Media to Ship in 2006
http://www.dailytech.com/article.aspx?newsid=1478

First of all, products that will be readable and writable by ordinary red laser rather than blue laser will be shipped first. This is mainly due to the cost aspect.

Such a recording apparatus


The conventional magnetic recording method has already reached the limit, and the cause is due to a phenomenon called superparamagnetism (superparamagnism).

The superparamagnism is a ferromagnetic material, which is a ferromagnetic material because of the progress of miniaturization of the magnetic crystal grains to increase the recording capacity per density, the volume of the crystal grain is decreased, the crystal magnetization becomes unstable Is also a phenomenon that loses magnetism. Needless to say, recording can not be done if magnetism is lost. In other words, when the bit density becomes small due to high density, the magnetization direction on the recording medium rotates freely due to thermal fluctuation, and the magnetization information is lost. It seems to call this a super paramagnetic limit.

For details, refer to the following PDF file
http://www.idema.gr.jp/standard/2003.pdf
http://www.idema.gr.jp/standard/2002.pdf
http://www.fujitsu-ten.co.jp/gihou/jp_pdf/34/34in.pdf

This is temporarily but avoided what is called a so-called perpendicular magnetic recording system, called "PMR" for short.

What is perpendicular magnetic recording system 【PMR】 - meaning · description: IT term dictionary e-Words

In the perpendicular magnetic recording method, the direction of the magnetic field is perpendicular to the recording surface, and even if the density is increased, the magnetic domains can be taken large, and the surrounding magnetic domains strengthen the magnetic force.

However, this method is finally approaching the limit.

Although it will become "holographic drive" which is a recording medium of holographic method to solve this problem, the product to be thrown first will have capacity of 300 GB. The transfer rate is about 20 MB per second. Next it is input from 800 GB to 1.6 TB. The price is still undecided, but it is not cheap.

Personally I'm worried about how much I can store while keeping track of the capacity ......