Beam shaping for optical data storage

Edwin P. Walker; Tomas D. Milster

doi:10.1117/12.446739

30 October 2001 Beam shaping for optical data storage

Edwin P. Walker, Tomas D. Milster

Proceedings Volume 4443, Laser Beam Shaping II; (2001) https://doi.org/10.1117/12.446739
Event: International Symposium on Optical Science and Technology, 2001, San Diego, CA, United States

Abstract

The basic instrument used for optical data storage is a scanning laser microscope. Each device contains a beam from a laser diode that is collimated, shaped and focused with an objective lens to produce a microscopic spot on the recording media. The reflected light is collected by the objective lens and directed to data and servo detectors with a beam splitter. Data density on the storage medium is primarily defined by the size and shape of the focused laser beam used to scan the data. Several interesting techniques have been used to shape the focused spot in a way that decreases the primary feature of the spot, thus increasing density. For example, both amplitude and phase filters have been used to decrease the central lobe, at the expense of increased sidelobe levels. Effects of the sidelobes can be minimized with special electronic circuits. The configuration of the readout optics also can influence density. That is, optical filters can be placed in the collection pupil to improve the system transfer function. When combined with electronic shaping circuits, the optical filters significantly improve device performance. This paper reviews the techniques used for beam shaping in optical data storage with an explanation of each technique and its success or failure.

Citation Download Citation

Edwin P. Walker and Tomas D. Milster "Beam shaping for optical data storage", Proc. SPIE 4443, Laser Beam Shaping II, (30 October 2001); https://doi.org/10.1117/12.446739

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