SONY

Blue Violet Laser & High Performance Lens

Professional Disc utilises blue-violet laser technology to achieve a smaller laser beam spot. Optical wavelength becomes increasingly shorter as they go from red to blue, and whereas DVDs and MOs use red laser with a wavelength of 650nm, Professional Disc uses a blue-violet laser wavelength of 405nm. The lens converges this short wavelength, blue-violet laser to a small beam spot. The ability of a lens to converge light is measured in NAs (Numerical Apertures). While DVDs use NA 0.6 lenses, and MOs use NA 0.575 lenses, Professional Disc is equipped with a high performance NA 0.85 lens. The blue-violet laser and high performance lens enables Professional Disc to perform high density recording by decreasing the dimensions of the laser beam spot to about 1/5 of DVDs.