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:
Jun. 08, 2004
Filed:
Jul. 20, 1999
Wolfgang Dultz, Frankfurt, DE;
Heidrun Schmitzer, Regensburg, DE;
Leonid Beresnev, Darmstadt, DE;
Eric Hildebrandt, Frankfurt, DE;
Deutsche Telekom AG, Bonn, DE;
Abstract
A quantum cryptography system using electrooptical liquid crystal modulators which change the polarization and which are designed as electrically rotatable retardation plates whose two birefringent axes are rotated by the applied electrical field around an angle &thgr; which depends on the strength of this field. A &lgr;/2 retardation plate rotates the elliptically polarized light striking the plate around an angle 2&thgr; at speeds in the microsecond range. The quantum cryptography system can be used for interception-proof data transmission over transmission links that are accessible to the public.