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, 2012
Filed:
Jun. 19, 2009
Shin Arahira, Tokyo, JP;
Shin Arahira, Tokyo, JP;
Oki Electric Industry Co., Ltd., Tokyo, JP;
Abstract
An optical m-ary modulator includes an optical loop forming a polarization maintaining closed optical path. A loop input-output unit splits linearly polarized input signal light into a first component and a second component and feeds the first and second components into the optical loop in opposite directions. A pair of phase modulators modulate the first and second components according to respective control signals. The loop input-output unit recombines the modulated first and second components. The optical phase bias unit creates a phase difference between the first and second components so that they combine to form an m-ary modulated optical signal. Since the first and second components travel around the same optical path, when they recombine their phases are correctly aligned, making the modulator immune to environmental effects and permitting the use of high-speed optical modulation techniques.