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Proceedings Paper

Servo lens design for NVD optical pick-up
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Paper Abstract

The NVD(Next generation Versatile Disc) OPU(Optical Pick-Up),based on general red light, is able to read a new type of disk which has 15 GB capacity with 2 layers on one side. The linear span of the focus error signal of original NVD OPU light path is shorter than the requirement proposed by the electron servo system. Increasing the thickness of the tilted-parallel-plate to broaden the linear span will increase the coma aberration which will deteriorate the servo accuracy. Furthermore, the thickness of the tilted-parallel-plate is related to the coexistence of DVD and CD servo signal. Therefore, an aberration-compensated and multi-freedom servo lens for NVD OPU is necessary. The servo lens proposed in this paper is a single lens, which the first surface is a combination of cylindrical surface and tilted surface, and the rear surface is a common spherical surface. According to the conversion of Zernike-to-Seidel wavefront aberration, a given amount of astigmatism will be achieved by bending the curvature of the cylindrical surface to broaden the linear span, and the coma will be corrected by the tilted surface. The function of the spherical surface is guaranteeing the coexistence of DVD and CD servo signal. Finally, the specification of the servo lens and simulation result of the whole system will be addressed.

Paper Details

Date Published: 19 March 2009
PDF: 7 pages
Proc. SPIE 7125, Eighth International Symposium on Optical Storage and 2008 International Workshop on Information Data Storage, 712521 (19 March 2009); doi: 10.1117/12.822295
Show Author Affiliations
Dexi Wang, Tsinghua Univ. (China)
Xuemin Cheng, Tsinghua Univ. (China)
Jianshe Ma, Tsinghua Univ. (China)


Published in SPIE Proceedings Vol. 7125:
Eighth International Symposium on Optical Storage and 2008 International Workshop on Information Data Storage
Fuxi Gan, Editor(s)

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