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:
Sep. 27, 2011
Filed:
Feb. 08, 2008
Jianying Zhou, Acton, MA (US);
Xueyan Zheng, Andover, MA (US);
Kevin J. Mccallion, Charlestown, MA (US);
Daniel Mahgerefteh, Palo Alto, MA (US);
Hongmin Chen, Waltham, MA (US);
Guoxi Sun, Woburn, MA (US);
Parviz Tayebati, Boston, MA (US);
Jianying Zhou, Acton, MA (US);
Xueyan Zheng, Andover, MA (US);
Kevin J. McCallion, Charlestown, MA (US);
Daniel Mahgerefteh, Palo Alto, MA (US);
Hongmin Chen, Waltham, MA (US);
Guoxi Sun, Woburn, MA (US);
Parviz Tayebati, Boston, MA (US);
Finisar Corporation, Sunnyvale, CA (US);
Abstract
The frequency chirp modulation response of a directly modulated laser is described using a small signal model that depends on slow chirp amplitude s and slow chirp time constant τ. The small signal model can be used to derive an inverse response for designing slow chirp compensation means. Slow chirp compensation means include electrical compensation, optical compensation, or both. Slow chirp electrical compensation can be implemented with an LR filter or other RF circuit coupled to a direct modulation source (e.g., a laser driver) and the directly modulated laser. Slow chirp optical compensation can be implemented with an optical spectrum reshaper having a rounded top and relatively large slope (e.g., 1.5-3 dB/GHz). The inverse response can be designed to under-compensate, to produce a flat response, or to over-compensate.