Microminiaturized Aspherical Single Lens with Numerical Aperture of 0.9 for Blue Laser Diode

A single lens with an effective diameter of 0.3 mm and a high numerical aperture (NA) of 0.9 for a blue laser diode has been developed. The current wavefront aberration of the lens is approximately equal to that of a conventional high-NA lens. The optical flying head with a mold process lens (MPL) can be respectively designed so that the disk-tilt margin may become wide for each cover layer thickness of the disk (compact disk, digital versatile disk, etc.).