The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 29, 1994
Filed:
Jul. 13, 1993
Yu Sheng Bai, Palo Alto, CA (US);
Ravinder Kachru, Redwood City, CA (US);
SRI International, Menlo Park, CA (US);
Abstract
A method and apparatus for coherent time-domain optical data storage utilizing a randomizing phase modulation to increase storage capacity. A laser (10) generates write. read, and data pulses which are applied to an acousto-optic modulator (11), which modulates the pulses according to a modulation signal received from a radio-frequency modulator (12), and the modulated pulses are applied to the storage medium (13). The data signal to be recorded on the storage medium is subjected to spread-spectrum modulation, and in particular to pseudo-random phase modulation. The RF-modulator (12) modulates the write and read pulses with a frequency-chirping modulation and modulates the data pulse with the spread-spectrum modulated data signal before applying the respective pulses to the storage medium. The result is that a significantly longer data signal may be effectively recorded on the optical storage medium for a given characteristic de-phasing time of the medium.