“A Way to Cram 1,000 Terabytes onto a Single DVD or a full peta byte of data” —-BLU-RAY DISC

    Its bigger brother Blu-ray has stolen the spotlight, paltry 4.7 GB DVDs have slowly started to fade into obscurity. But could they be poised for a comeback? A trio of Chinese scientists have discovered a breakthrough process that could, at least in theory, allow a DVD to store a whopping 1,000 TB—or a full petabyte—of data. ——-Blu-ray.

With the advent of blu-ray disc, the only format that offers a considerable increase in storage capacity with its 25 to 50 GB data capacity. This allows for the next big application of optical media: the distribution and recording of high definition video in the highest possible quality


blu ray disk is a digital video disk that can record, store and play back high definition video, digital audio and computer data.

“As we probably know that a single-sided, standard DVD is capable of storing 4.7 GB of data (i.e. about the size of the average two-hour, standard-definition movie). However, high-definition films have much greater clarity and need five times more bandwidth. Standard DVD disks are inadequate and here comes the solution BLU-RAY DISK.”

The storage capacity of a DVD is limited by the size of the laser beam burning the small pits that represent the streams of data. Blu-ray increased this capacity by switching to even smaller blue lasers, but the storage capacity of that technology maxed out as well.

BD Key Characteristics

  • High capacity storage of video and data – Up to 9 hours of high definition video or 23 hours of standard definition video or up to 50GB of data. This is over 5 times the capacity of SDVDs making Blu-ray discs particularly well suited for the distribution of high-definition feature films.
  • Uncompressed surround sound – Ensures highest quality sound reproduction
  • Increased data transfer rate –. A SDVD has a data transfer rate of about 1.3MB per second as compared to the Blu-ray data transfer rate of 4.2MB bytes per second
  • Improved interactive features – network and Internet connectivity and enhanced menu navigation help provide a more seamless viewing experience.
  • Better scratch resistance 
  •  Broadest Industry Support
  1. Cost effective – Although BD media currently cost more than SDVD media, the capability to store over 5 times the data on a Blu-ray disc results in a lower cost per GB than for SDVDs.

How Blu Ray Works?

As we probably already know, digital information is stored on optical devices in pits along a spiral groove running along from the center of the disc to its edge. Laser beams read this information and convert it into an electrical signal which may be processed by a computer in order to decode and display the stored data.

More pits along the spiral groove basically translates into more store information, thus researchers are continuously working to minimizing and compacting together more pits on a given surface area. DVDs, for example, use 650-nanometer red lasers during operation, however by decreasing the wavelength of the laser beam to 405 nanometers – blue light, which also gives the disc format its name – smaller pits may be written/read on the support surface.


  • Read information recorded in pits as small as 0.15 microns (µm) i.e. twice as small as the pits on a DVD
  • It has reduced the track pitch from 0.74 microns to 0.32 microns.
  • The combination of the smaller pits, smaller beam and shorter track pitch mean that a single-layer Blu Ray disk can hold in excess of 25 GB of information, that’s about five times the amount of information that can be stored on a DVD disk.
  • Blu-ray discs also solve the problems related to birefringence and disc tilt


With BLU-RAY you can:

  • Record high-definition television (HDTV) without any quality loss.
    • Instantly skip to any spot on the disc.
    • Record one program while watching another on the disc.
    • Create playlists.
    • Edit or reorder programs recorded on the disc
    • Automatically search for an empty space on the disc to avoid recording over a program access the Web to download subtitles and other extra features
    • Data transfer rates on Blue Ray are 36 Mbps (megabits per second). Much higher than DVD 10 Mbps. A Blu-ray disc can record 25 GB of material in a little over an hour and a half!
    • A Blu ray Disc Offers Increased Security
    • Blu ray discs are better protected than DVDs. A secure encryption system is fitted with each disk; this is a unique ID that protects against video piracy and copyright infringement.

How Blu-ray Reads Data?

The Blu-ray disc overcomes DVD-reading issues by placing the data on top of a 1.1-mm-thick polycarbonate layer. Having the data on top prevents birefringence and therefore prevents readability problems. And, with the recording layer sitting closer to the objective lens of the reading mechanism, the problem of disc tilt is virtually eliminated. Because the data is closer to the surface, a hard coating is placed on the outside of the disc to protect it from scratches and fingerprints.

BD Applications

– High Definition Television Recording
– High Definition Video Distribution
– High Definition Camcorder Archiving
– Mass Data Storage
– Digital Asset Management and Professional Storage


“A versatile design and top-of-the-line specifications mean that it is suitable for a full range of other purposes as well”.





Blue-ray associations.

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