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:
Jan. 27, 2004
Filed:
Jul. 24, 2001
Applicant:
Inventors:
David C W Herbert, Malvern, GB;
Edward T R Chidley, Tewkesbury, GB;
Assignee:
QinetiQ Limited, London, GB;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H01J 4/014 ;
U.S. Cl.
CPC ...
H01J 4/014 ;
Abstract
The present invention provides an avalanche photo-diode detector arrangement comprising two avalanche photo-iodes, which are each reverse biased to just below their breakdown voltage, are arranged back-to-back and are arranged in series with an oscillating voltage source such that the photodiodes exceed their breakdown voltage out of phase with each other. The oscillating voltage has a period of at least twice and preferably between 4 and 32 times, the avalanche zone transit time of the photo diodes. The detector arrangement achieves low noise and is able to distinguish dark counts.