DATA STORAGE DEVICES

What Are Data Storage Devices

All device Using for storing data. Recording can be done Mechanically, Magnetically, or Optically                            

  

HVD : Holographic Versatile Discs

Hold 300 Gigabytes Of Data

10 Times Faster Than A Normal DVD

Little Wider Than Conventional DVDs

And Also Slightly Thicker.

Completely Based on concept of Holographic-memory

Developed By InPhase Tech. & Optware Tech.

    

Basics Of Holographic Memory

Phenomena of storing information in a light-sensitive crystal material using the interference of laser light.

The recorded patterns of light are called a hologram.

Hologram Is Creating By A Focused Beam – A Laser Light

This Beam Is Split Into Two Parts

1) Reference beam

2) Information beam

Basics Of Holographic Memory

Reference Beam Remains Unchanged

Information Beam Passes Through An Image

Then Carries That Image In Its Waveforms

When Both Beams Intersect, It Creates Pattern Of Light Interference.

Data Stored In Hologram

Holograms Can Theoretically Store Equal To 1 Bit/cubic block The Size Of The Wavelength

Holographic Versatile Discs

This Is 40 year old concept. Initially Difficult To MakeBecause Systems Send Reference Beam & Info. Beam Into Recording Medium On Diff. axes HVDs Can More Than 1 Terabyte (TB).Accessed Entire Page At A Time Instead of Sequentially . HVD Stores Info. In Almost The Entire Volume Of The Disc.Stores 60,000 Bits Info. In One Pulse Of Light.

How Data Stores In HVDs

Structure Of HVDs

Structure Of HVDs In Thickness

1. Green writing/reading laser (532 nm)2. Red positioning/addressing laser (650 nm)3. Hologram (data)4. Polycarbon layer5. Photopolymeric layer (data-containing layer)6. Distance layers7. Dichroic layer (reflecting green light)8. Aluminium reflective layer (reflecting red light)9. Transparent baseP. PIT

The HVD System

A simplified HVD system consists of the following main components:

Blue or green laser

Beam splitter/merger

Mirrors

Spatial light modulator (SLM)

CMOS sensor

Photopolymer recording medium

HVDs Writing System

HVDs Reading System

HVDs Comparison

FACTORS Blu-ray HD-DVD HVD

Initial cost for recordable disc

Approx. $18 Approx. $10 Approx. $100

Initial cost for recorder/player

Approx. $2,000 Approx. $2,000 Approx. $3,000

Initial storage capacity 54 GB 30 GB 200 GB

Read/write speed 36.5 Mbps 36.5 Mbps 1 Gbps

HVDs Comparison

Storage Medium Access Time Data Transfer Rate Storage

Capacity

Holographic Memory

2.4 s 10 GB/s 400Mbits/cm sq.

Main Memory (RAM)

10 – 40 ns 5 MB/s 4.0 Mbits/cm sq.

Magnetic Disk 8.3 ms 5 – 20 MB/s 100 Mbits/cm sq.

Summary Slide

Different Type Of Data Storage Devices Are:-Mechanical

Punch card, Paper Tape

Magnetically Recording Tape, Gramophone

Optical CDs, DVDs, HD-DVDs

Coming Day Technology Blu-Ray Disk (BDs)

Future World Devices Holographic Versatile Discs

For Listening Us Carefully