CD/DVD/Blu-Ray Travis Harrall, Zac Spencer & Trevor Green DVD/CD/Blu-Ray are all optical data storage devices. All three employ lasers and the principle of point-by-point scanning of an object to extract the recorded information on the disc. They differ in their capacity to store data and by the type of laser light required to decode that data.

The Discs Data stored in the series of lands and bumps on disc Tracks spiral outward from center 1.2mm thick, maximum radius of 12cm

The Player Disc drive motor Lens/Laser system Tracking drive

How are they different? CDDVDBlu-Ray Storage Capacity.65 GB per layer4.7 GB per layer23 GB per layer Numeric Aperture Wavelength of Laser780 nm (infrared)650 nm (red)405 nm (purple) Track Pitch1.6 μm.74 μm.32 μm Maximum Rotating Speed 500 rpms1600 rpms10,000 rpms Minimum Size of Pits.83 μm.4 μm.14 μm

Beam Diameter CDDVDBlu-Ray Storage Capacity.65 GB per layer4.7 GB per layer23 GB per layer Numeric Aperture Wavelength of Laser780 nm (infrared)650 nm (red)405 nm (purple) Track Pitch1.6 μm.74 μm.32 μm Maximum Rotating Speed 500 rpms1600 rpms10,000 rpms Minimum Size of Pits.83 μm.4 μm.14 μm

Bibliography  Braat, Joseph, P. Dirksen, and Augustus Janssen. Diffractive read-out of optical discs Web. 19 Nov  Kuhn, Kelin J. Laser Engineering. N.p.: Prentice Hall, Print.  Pohlmann, Ken C. The Compact Disc Handbook. 2nd ed. Vol. 5. Madison: A-R Editions, Inc, Web. 19 Nov  van de Nes, A S, J J M Braat, and S F Pereira. "High-density optical data storage." Reports of Progress in Physics 69 (2006): Web. 19 Nov       9.html  Braat, Joseph, P. Dirksen, and Augustus Janssen. Diffractive read-out of optical discs Web. 19 Nov  Kuhn, Kelin J. Laser Engineering. N.p.: Prentice Hall, Print.  Pohlmann, Ken C. The Compact Disc Handbook. 2nd ed. Vol. 5. Madison: A-R Editions, Inc, Web. 19 Nov  van de Nes, A S, J J M Braat, and S F Pereira. "High-density optical data storage." Reports of Progress in Physics 69 (2006): Web. 19 Nov       9.html