Interferometric Preformatting of Optical Disks
Original Publication Date: 1988-Jun-01
Included in the Prior Art Database: 2005-Feb-15
Photolithographic generation of concentric recording tracks 10 on an optical disk 9 is obtained by an interference field of a plane wave 5, travelling in the direction of the axis of rotation (z-axis) of the disk, and of a coherent beam 7A, 7B which is rotationally symmetric relative to the z-axis. In the figure, the cone-shaped beam 7A, 7B is generated by directing a plane wave 7 onto a high-precision cylindrical glass rod 8 at an angle a; the transmitted beam 7A and the reflected beam 7B illuminate an annular area on the disk 9 between radii R1, R2, so that interference rings with a mutual spacing of g d = ____ cosa are recorded in the photoresist layer covering the disk.