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:
Aug. 30, 2011
Filed:
Oct. 31, 2006
Wakako Maeda, Tokyo, JP;
Akio Tajima, Tokyo, JP;
Akihiro Tanaka, Tokyo, JP;
Seigo Takahashi, Tokyo, JP;
Wakako Maeda, Tokyo, JP;
Akio Tajima, Tokyo, JP;
Akihiro Tanaka, Tokyo, JP;
Seigo Takahashi, Tokyo, JP;
NEC Corporation, Tokyo, JP;
Abstract
A method and apparatus for measuring the optical power of very weak light arriving at a receiver, by using a photon detector, are provided. A photon detector detects the presence or absence of the arrival of a photon in accordance with bias application timing. For a train of optical pulses coming in at an arbitrary timing in respective time slots, the bias application timing is sequentially shifted within the range of a time slot. Each time a shift is made, the number of photons detected is counted by a photon counter. Based on this number of photons, the optical power of the train of the optical pulses is measured.