Spatio-angular multiplexing geometry for volume holographic storage

US5844700A · kind A · utility

Assignee

• The Board of Trustees of the Leland Stanford Junior University · US

Inventors

• Muthuveerappan Jeganathan · Thousand Oaks, US
• Matthew C. Bashaw · Santa Clara, US
• Lambertus Hesselink · Woodside, US

Key dates

• Filing date: Jul 24, 1996
• Grant date: Dec 1, 1998
• Expiry date: Jul 24, 2016

Classification

• Technology area (CPC G): Physics
• CPC primary: G03H1/265
• WIPO field: Optics
• WIPO sector: Instruments

Abstract

Partially overlapping holograms are stored in a cylindrical volume holographic storage medium capable of rotation about and translation along its longitudinal axis. The reference and signal beams are mutually perpendicular, and each is perpendicular to the longitudinal axis. An index-matched housing encloses the medium laterally. An optional helically-varying optical axis (c-axis) orientation allows recording at constant angular intervals over a full revolution. Signals from stored pages are used to dynamically adjust the positioning of the medium relative to the light beams as the medium continuously spins at high velocity, and to control the access of the signal beam to the readout camera.