We propose an optical pickup that acquires data from both layers of a dual-layer digital versatile disk simultaneously. An adaptive optical element that uses liquid crystals creates two axial foci separated by a spacing of 55 μm, which is the distance between the two layers. The spacing between the foci can be varied by the adaptive element. The separation of the reflected light into TE and TM polarized light, corresponding to each of the layers, is made by dielectric gratings that are characterized by high aspect ratios. Electron-beam lithography and reactive ion etching techniques were used to produce the submicrometer structures. All fabricated elements were assembled in a pickup system, whose properties were measured.
© 2001 Optical Society of America
(050.1950) Diffraction and gratings : Diffraction gratings
(130.3120) Integrated optics : Integrated optics devices
(210.0210) Optical data storage : Optical data storage
(210.4590) Optical data storage : Optical disks
Svetomir Stankovic, Daniel Dias, Mathias Hain, Shanti Bhattacharya, Robert Glöckner, Chialou Karaboué, Lhoucine Benmohammadi, Fouad Guessous, Lingli Wang, Theo Tschudi, Margit Ferstl, Edgar Pawlowski, and Ralf Steingrüber, "Integrated Optical Pickup System for Axial Dual Focus," Appl. Opt. 40, 614-621 (2001)