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:
Oct. 02, 2018
Filed:
Apr. 10, 2015
Nippon Telegraph and Telephone Corporation, Tokyo, JP;
Ntt Electronics Corporation, Yokohama-shi, Kanagawa, JP;
Mikio Yoneyama, Yokosuka, JP;
Hiroto Kawakami, Yokosuka, JP;
Takashi Ono, Yokosuka, JP;
Akihiko Matsuura, Yokosuka, JP;
Tomoyoshi Kataoka, Yokosuka, JP;
Katsuya Tanaka, Yokohama, JP;
Masahiro Tachibana, Yokohama, JP;
Yuya Oyama, Yokohama, JP;
Nippon Telegraph And Telephone Corporation, Tokyo, JP;
NTT Electronics Corporation, Yokohama-shi, Kanagawa, JP;
Abstract
A light modulation device detects a power of the modulated optical signal modulated by each of an I-component optical modulator and a Q-component optical modulator, synchronously-detects a component of a frequency fd from the power of the modulated optical signal, outputs a dither signal of a frequency fd/n (where n is a positive integer equal to or larger than 1) applied to a first bias voltage or a second bias voltage when adjusting the first bias voltage or the second bias voltage, outputs two dither signals having a frequency fd/m (where m is a positive integer equal to or larger than 1, where n<m), which are mutually orthogonal to each other, applied to the first and second bias voltages when adjusting a third bias voltage, and adjusting bias voltages by increasing or decreasing bias voltages based on a synchronous detection result.