Focus Error Detection In Optical Data Storage Systems

Richard V. Johnson

doi:10.1117/12.958070

12 February 1980 Focus Error Detection In Optical Data Storage Systems

Richard V. Johnson

Proceedings Volume 0200, Laser Recording and Information Handling; (1980) https://doi.org/10.1117/12.958070
Event: 23rd Annual Technical Symposium, 1979, San Diego, United States

Abstract

One of the most distinctive features of the optical disk mass storage technology which has been under development at Xerox Electro-Optical Systems is the extremely high numerical aperture (NA) of the objective lenses used for writing and playback. A disk system with a 0.90 NA lens has over five times the data capacity of a comparable disk system with a 0.40 NA lens. This increased data capacity comes at the price of a reduced depth of focus and significantly increased sensitivity to aberrations. The subject of this paper is the performance of the "skew beam" and the "Foucault knife-edge" techniques for sensing focus errors. Specific topics include: (1) An analysis for optimizing the sensitivity of the skew beam configuration, (2) An observation of the close similarity between the skew beam and the Foucault knife-edge techniques, and (3) A partial list of sources of aberrations unique to high numerical aperture optics, and their impact upon the performance of the focus error sensing detector.

Citation Download Citation

Richard V. Johnson "Focus Error Detection In Optical Data Storage Systems", Proc. SPIE 0200, Laser Recording and Information Handling, (12 February 1980); https://doi.org/10.1117/12.958070

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available