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:
Jul. 14, 2026
Filed:
Jul. 19, 2022
National Institute of Information and Communications Technology, Tokyo, JP;
National University Corporation Hokkaido University, Hokkaido, JP;
Mikio Fujiwara, Tokyo, JP;
Masahiro Takeoka, Tokyo, JP;
Masahide Sasaki, Tokyo, JP;
Akihisa Tomita, Hokkaido, JP;
Abstract
A phase modulator calibration method includes steps of: providing a first delay interferometer to be used as a phase calibration reference and a second delay interferometer in which a phase modulator to be calibrated is installed in an optical path; for each of the first and second delay interferometers, measuring a delay time based on a time interval between pulses split from one input pulse and synchronizing the delay time with a cycle of a transmission clock; for the first delay interferometer, adjusting a phase difference so that input continuous-wave laser light produces an intensity-enhancing interference at an output; and determining the control signal with a calibration circuitry formed by connecting the first delay interferometer as a front stage and the second delay interferometer as a rear stage in a cascaded manner.