How using shorter-wavelength laser allows more information to be stored

In summary, information is stored on a disc in pits that are scanned by a laser beam. The width of the laser beam is a significant limitation on the amount of information that can be stored on a disc. By decreasing the wavelength of the light, the size of the pits can be decreased and more information can fit on a line of given length. Additionally, "pressed" discs have two layers and increasing the laser power can transmit through the first layer onto the second layer. For more information, websites such as Wikipedia and "How Stuff Works" can be referenced. It is also worth noting that current data storage is limited in 2D space, but there is ongoing research in holographic 3D data storage.
  • #1
ah lai
5
0
Information is stored in a series of pits on the disc. These pits are scanned by a laser beam. An significant limitation on amount of information that can be stored on a disc is width of laser beam.

I knew why the width of laser beam is important coz diffraction effect of loght.


How using shorter-wavelength laser allows more information to be stored on disc of same size??

Any website i can refer to ? Thanks!
 
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  • #2
Well for one, decreasing the wavelength of the light, allows to decrease the size of the pits, hence more will fit on a line of given length.
 
  • #3
Also don't forget that "pressed" discs have two layers, by increasing the laser power, it is possible to trasmit through the first layer onto the second layer.

Try looking for DVD under wikipedia:

http://en.wikipedia.org/wiki/DVD

and "how stuff works":

http://www.howstuffworks.com/dvd.htm

Also Note that information is limited in 2d space (ok it is quasi 3d space, since we have two layers)
Future data storage is working on holographic 3d data storage (which is still optical based):

http://en.wikipedia.org/wiki/Holographic_memory

http://en.wikipedia.org/wiki/HDSS

http://www.inphase-technologies.com/
 
  • #4
I was aware that it had to do with diffraction patterns that determined how much data. The shorter the wavelegth, the closer the (spiral) of information is on the disc.
 

1. How does using shorter-wavelength laser allow more information to be stored?

Shorter-wavelength lasers have a smaller beam diameter, which means they can focus and write smaller data bits on a storage medium. This allows for a higher density of data to be stored, resulting in more information being stored overall.

2. What is the relationship between wavelength and storage capacity?

The shorter the wavelength of a laser, the smaller the spot size it can create on a storage medium. This leads to a higher density of data, and therefore a larger storage capacity.

3. Can using shorter-wavelength laser improve data storage speed?

Yes, shorter-wavelength lasers can write data at a faster rate compared to longer-wavelength lasers. This is because they can create smaller data bits in a shorter amount of time.

4. Are there any limitations to using shorter-wavelength laser for data storage?

One limitation of using shorter-wavelength lasers is that they are more susceptible to interference and scattering, which can affect the accuracy and reliability of data storage. Additionally, the technology for producing and using shorter-wavelength lasers can be more expensive and complex.

5. How does the use of shorter-wavelength laser impact the lifespan of data storage media?

Shorter-wavelength lasers can help to increase the lifespan of data storage media by allowing for smaller data bits to be written, reducing the wear and tear on the storage medium. This can also lead to a longer overall lifespan of the storage device.

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