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:
Dec. 11, 2007
Filed:
Apr. 03, 2003
Tattee Khayim, Kawasaki, JP;
Ko Koga, Kitakyushu, JP;
Hiroyuki Agatsuma, Kitakyushu, JP;
Mitsuru Sugawara, Kawasaki, JP;
Sadao Tanikoshi, Kawasaki, JP;
Tattee Khayim, Kawasaki, JP;
Ko Koga, Kitakyushu, JP;
Hiroyuki Agatsuma, Kitakyushu, JP;
Mitsuru Sugawara, Kawasaki, JP;
Sadao Tanikoshi, Kawasaki, JP;
Kabushiki Kaisha Toshiba, Tokyo, JP;
Abstract
An optical modulating device including a driving circuit generating a driving voltage corresponding to an input signal, an oscillator generating a signal having a low frequency signal lower than that of the input signal, an MZ modulator receiving a DC bias voltage superposed with the low frequency signal and the driving voltage, to generate a modulated optical signal according to the input signal, a photoelectric converting unit for converting the modulated optical signal into an electric signal, a low frequency signal detecting circuit which extracts the low frequency signal component contained in the electric signal, multiplies the low frequency signal component by the low frequency signal outputted by the low frequency oscillator, and then extracts a DC component from a multiplied output signal, and a control circuit for extracting a maximized DC component from the low frequency signal detecting circuit by controlling the DC bias voltage.