3d optical data storage technology
DESCRIPTION
3d optical data storageTRANSCRIPT
It is the term given to any form of optical data storage in which information can be recorded and/or read with three dimensional resolution. This innovation has the potential to provide terabyte-level mass storage on DVD-sized disks.
Data recording and readback are achieved by focusing lasers within the medium.
INTRODUCTION
HISTORY
In the 1970s, Valeri Barachevskii demonstrated that this photochromism could be produced by two-photon excitation.
Finally at the end of the 1980s Peter T. Rentzepis showed that this could lead to three-dimensional data storage
Various storage devices till date
I Generation : Compact Disc(CD) – 650/700MB Laser wavelength – 780nm Color of laser – RED
II Generation : Digital Versatile Disc(DVD) – 4.7GB Laser Wavelength - 650nm Color of laser - RED
III Generation : Blu ray Disc(BD) - 25/50GB Laser wavelength – 405nm Color of laser - BLUE
PROCESS OF WRITING DATA
Non resonant multiphoton absorption ط
Sequential multiphoton absorption ط
Microholography ط
Recording during manufacturing ط
BLU RAY DISC Invented by SHVJI NAKAMURA of NICHA Corporation.It has the main use of High Definition video & Data Storage.The name Blu-ray Disc derives from the blue-violet laser used to read the disc.
BD TECHNOLOGY
Pits-Spiral grooves that run from center of the disc to its edges.
Bumps-Other sides of these above edges.
Track Pitch-It is the distance between the two tracks(of pits) on the surface.
DATA IS STORED IN THE PITS
DISC STRUCTURE
SPECIFICATIONS OF BD Laser and optics
Hard coating technology
Recording SpeedDrive speed
Data rate Theoretical write time for BD (in minutes)
Mb/sec MB/sec Single layer Double layer
1x 36 4.5 90 180
2x 72 9 45 90
4x 144 18 22.5 45
6x 216 27 15 30
8x 288 36 11.25 22.5
12x 432 54 7.5 15
BD-ROM (read only) : For pre-recorded content
BD-R (Recordable) : For storing HD data on the disc
BD-RW (Rewritable) : For PC data storage
BD-RE (Rewritable) : For HD TV storage
FORMATS
CD/DVD vs. BDBD
Data is stored on the top of the 1.1mm thick polycarbonate layer
Numerical Aperture is 0.85
Track Pitch 0.32 micron
Storage capacity is 25/50GB.
Image resolution is HIGH
DVD Data is sandwiched between two 0.6mm thick poly carbonate layers.
Numerical Aperture is 0.65
Track Pitch 0.74 micron
Storage capacity is 15/30GB
Image resolution is POOR
Pictorial & Graphical comparison
ADVANTAGES Instantly skip to any part of the disc.
Record HDTV without any quality loss.
Multi-tasking.
Automatically search for an empty space.
Higher density enables better data seek times. and many more……
FUTURE IN BD
Than Q
QUERIES ??????