By the late 1990s blue lasers were used for making the masters for DVD discs, but this process used hugely expensive special laser-beam recorders the size of a wardrobe and needing a super-clean, vibration-free environment in which to work properly. The challenge for optical drive … [Read more...]
Blu-ray Disks (BD) – blue laser optical disk technology
Optical disc technologies such as DVD, DVD-R, DVD-RW, and DVD-RAM employ a 650 nm red laser, bond 0.6mm-thick discs and use lenses with a numerical aperture (NA) of 0.6. By employing a short wavelength (405nm) blue violet laser, the Blu-ray Disc (BD) successfully minimises its beam … [Read more...]