Real-time adaptive encoding for 3D optical memories

Leo Selavo; Donald M. Chiarulli; Steven Peter Levitan

doi:10.1117/12.454039

23 January 2002 Real-time adaptive encoding for 3D optical memories

Leo Selavo, Donald M. Chiarulli, Steven Peter Levitan

Proceedings Volume 4459, Photorefractive Fiber and Crystal Devices: Materials, Optical Properties, and Applications VII, and Optical Data Storage; (2002) https://doi.org/10.1117/12.454039
Event: International Symposium on Optical Science and Technology, 2001, San Diego, CA, United States

Abstract

There are a variety of factors that can limit the set of allowable code words that are useable on an optical memory block. In this paper, we will primarily consider inter- symbol interference (ISI) and the noise margins required to represent an individual bit. Fo example, code words must maintain a specific topological separation of '1' bits so that ISI does not raise the intensity of neighboring '0's' above a pre-set threshold. Typically this is accomplished by a static encoding that uses a pre-selected set of code words based on these properties of the storage media and the optical system. Alternatively, our approach provides for a dynamic analysis of all data currently stored in the region surrounding a particular block and defines the allowable code words uniquely for each block. We assume the existence of a 'smart' read head that is capable of analyzing a page of data and calculating the allowable codes in real-time based on the actual data in the surrounding region. We use point-spread function based mathematical model for optical readout system to evaluate and carry out data encoding. Our experiments show 81% spatial utilization while recent publications present only 45% utilization.

Citation Download Citation

Leo Selavo, Donald M. Chiarulli, and Steven Peter Levitan "Real-time adaptive encoding for 3D optical memories", Proc. SPIE 4459, Photorefractive Fiber and Crystal Devices: Materials, Optical Properties, and Applications VII, and Optical Data Storage, (23 January 2002); https://doi.org/10.1117/12.454039

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