Blue Laser DVD

What is blue laser DVD technology?

The difference between a standard DVD player and a Blue Laser DVD player is in wavelength of the laser used to read the information. A blue laser is used instead of the red lasers that are used on earlier discs. At 450 nanometers, blue lasers have a shorter wavelength than red lasers, which are 650 nanometers. The beam can therefore be focused on a smaller area, which means that you can fit more data on the same sized disc.

Techno-mumbo-jumbo

Three primary blue-laser technologies are now available: ZnSe lasers, GaN lasers, and second-harmonic generation (SHG) lasers.

ZnSe lasers brought the first success to the field, but these lasers have problems with relatively short life-time at the required power levels. They are also close to the green end of the blue range, at 460 to 520 nm.

GaN lasers have shown high reliability at wavelengths as short as 370 nm. This technology is highly regarded in the industry.

SHG lasers are the most reliable and durable at the moment. This technology can either double the frequency of an infrared laser or directly generate a second harmonic in the blue portion of the spectrum. For example, for a given infrared laser with a wavelength of 850 nm, this technology will double the laser light frequency and produce blue light at 425 nm.

Blue laser discs are not readable on standard CD and DVD players and readers, but many blue laser drives will be able to playback the older disc formats. This means you won't have to repeat the pain you felt throwing away all those old VHS tapes in lieu of the original DVD technology.

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