28 November 2007 Design of an objective lens for optical disc systems employing a blue laser by scalar diffraction simulation
Author Affiliations +
We have designed a compatible objective lens for HD DVD/DVD/CD drives utilizing a multiple diffractive structure. In this case, if priority has been given to a high HD DVD diffraction efficiency, the CD diffraction efficiency is reduced. Therefore, plenty of noise light is generated at the entrance pupil diameter of a CD inner area which may cause a false signal in the focus error (FE) signal during CD playback. Furthermore, the quality of the spot and the side-lobe intensity gets worse due to the light at the entrance pupil diameter of a CD outer area, and hence, may cause recording and playback problems. To solve these problems, we improved the objective lens applying a scalar diffraction simulation. We separated the position of the false signal far away from the regular signal in the FE signal, and suppress the amplitude of the false signal much smaller than the regular signal in FE signal during CD playback to achieve the reliable focus servo. In addition, we managed to improve the spot and the side-lobe quality to a practical level during CD playback with providing an aperture filtering function on the objective lens.
© (2007) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Naoki Yamagata, Naoki Yamagata, Shuichi Takeuchi, Shuichi Takeuchi, Kenzo Yamanaka, Kenzo Yamanaka, Daisuke Koreeda, Daisuke Koreeda, Koichi Maruyama, Koichi Maruyama, } "Design of an objective lens for optical disc systems employing a blue laser by scalar diffraction simulation", Proc. SPIE 6834, Optical Design and Testing III, 68340M (28 November 2007); doi: 10.1117/12.759754; https://doi.org/10.1117/12.759754


Nonperiodic phase structures in optical disk systems
Proceedings of SPIE (January 10 2002)
How high an NA is too high?
Proceedings of SPIE (June 28 1999)
BD/DVD/CD compatible objective lens
Proceedings of SPIE (June 22 2006)
Variation of the read out signal in an optical disk...
Proceedings of SPIE (August 19 1998)

Back to Top