1. A.Arundeep ECE IV Year arundeepreddy@gmail.com

2.  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

3. 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

4. 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

5. PROCESS OF WRITING DATA ﻂ Non resonant multiphoton absorption ﻂ Sequential multiphoton absorption ﻂ Microholography ﻂ Recording during manufacturing

6. 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.

7. 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

8. DISC STRUCTURE

9. SPECIFICATIONS OF BD Laser and optics Hard coating technology Recording Speed Drive speed Data rateTheoretical write time for BD (in minutes) Mb/secMB/secSingle layerDouble layer 1x364.590180 2x7294590 4x1441822.545 6x216271530 8x2883611.2522.5 12x432547.515

10. 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

11. CD/DVD vs. BD BD 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

12. Pictorial & Graphical comparison

13. 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……

14. FUTURE IN BD