Lens That Writes on Both HD-DVD and Blu-Ray

Ricoh claims they have developed an optical component that reads and writes all disk formats — Blu-ray Disc and HD-DVD, as well as DVD and CD — with one pickup and one objective lens. The component is a 3.5-mm diameter, 1-mm thick round diffraction plate with minute concentric groves on both sides which function as a diffraction grating. Based on disc information the drive can identify which format disk is loaded, Ricoh’s optical diffraction component adjusts the laser beam with its diffraction grating for each format and passes it to the objective lens