Write-once volumetric optical disk using transparent recording material with an optical switching layer

A volumetric optical disk having multiple transparent films with optical switching layers is proposed as a recordable medium to increase the number of recording layers. In the disk, an optical switching layer is adopted to reduce laser energy decay and increase recording sensitivity for reading and recording, respectively. A well-defined deformation area (mark) with submicron to nanometric dimensions can be yielded precisely on the transparent films by a focused laser beam. The peak writing power of 7mW for a four-layer recordable medium, fabricated by molding and spin bonding techniques, was demonstrated experimentally as an example. The proposed volumetric disk can achieve a higher recording capacity by using conventional optical pickup units.