Effects of substrate birefringence on focusing and tracking servo signals in magneto-optical disk data storage

Satoshi Sugaya, M. Mansuripur

Research output: Contribution to journalArticle

7 Scopus citations


Using computer simulations based on the diffraction theory of high-N.A. systems, we examine the effects of substrate birefringence on servo signals in magneto-optical disk drives. Our attention is confined to systems that use the methods of push-pull tracking and astigmatic focus-error detection. We show that the amounts of birefringence typically observed in polycarbonate substrates do not in themselves cause problems for the servo channels. However, the presence of residual aberrations in the optical path (astigmatism in particular) can have devastating effects on the magnitude of the track-error signal and the stability of the focusing servo. We show that the combination of substrate birefringence and residual beam astigmatism can either improve or deteriorate the performance of the focusing servo, depending on the orientation of the aberration relative to the principal axes of the substrate.

Original languageEnglish (US)
Pages (from-to)5073-5079
Number of pages7
JournalApplied optics
Issue number22
StatePublished - Aug 1994


ASJC Scopus subject areas

  • Atomic and Molecular Physics, and Optics
  • Engineering (miscellaneous)
  • Electrical and Electronic Engineering

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