Differential spot-size focus servo

Tom D. Milster, Mark S. Wang, Fred F. Froehlich, J. L. Kann, Jeff P. Treptau, K. E. Erwin

Research output: Chapter in Book/Report/Conference proceedingConference contribution

5 Scopus citations


The performance of a differential spot-size (wax-wane) focus servo is described. Cross-talk from the tracks is analyzed in the single detector and differential focus circuits. Magnitude of the cross-talk is reduced by a factor of three in the differential circuit. A false FES signal is present when the spot crosses sector marks at an angle.

Original languageEnglish (US)
Title of host publicationProceedings of SPIE - The International Society for Optical Engineering
PublisherPubl by Int Soc for Optical Engineering
Number of pages6
ISBN (Print)0819406082, 9780819406088
StatePublished - 1991
EventOptical Data Storage '91 - Colorado Springs, CO, USA
Duration: Feb 25 1991Feb 27 1991

Publication series

NameProceedings of SPIE - The International Society for Optical Engineering
ISSN (Print)0277-786X


OtherOptical Data Storage '91
CityColorado Springs, CO, USA

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Computer Science Applications
  • Applied Mathematics
  • Electrical and Electronic Engineering


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