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:
May. 01, 2012
Filed:
Oct. 01, 2008
Keith Harrison, Stoke Gifford Bristol, GB;
William Munro, Stoke Gifford Bristol, GB;
Timothy Spiller, Stoke Gifford Bristol, GB;
Michael Tan, Palo Alto, CA (US);
Joanna Duligall, Stoke Gifford Bristol, GB;
Radu Ionicioiu, Stoke Gifford Bristol, GB;
Keith Harrison, Stoke Gifford Bristol, GB;
William Munro, Stoke Gifford Bristol, GB;
Timothy Spiller, Stoke Gifford Bristol, GB;
Michael Tan, Palo Alto, CA (US);
Joanna Duligall, Stoke Gifford Bristol, GB;
Radu Ionicioiu, Stoke Gifford Bristol, GB;
Hewlett-Packard Development Company, L.P., Houston, TX (US);
Abstract
In order to facilitate alignment of a QKD transmitter and QKD receiver, the transmitter is provided with a retro-reflector for returning to the receiver a photon beam originating at the latter. The transmitter is arranged to polarization modulate the retro-reflected beam. The transmitter is provided both with an intensity detector for generating an indication of retro-reflected photon intensity, and an intensity-dependent controller for controlling the QKD transmitter in dependence on the detected photon intensity. In one embodiment, this control involves aborting operation of the QKD transmitter upon an unexpectedly high photon intensity being detected; in another embodiment, the intensity indication is used to control the attenuation of the retro-reflected beam so as stabilize the average retro-reflected photon count per unit time.