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. 22, 2008
Filed:
Mar. 31, 2006
James D. Mcvey, Palo Alto, CA (US);
James D. McVey, Palo Alto, CA (US);
Finisar Corporation, Sunnyvale, CA (US);
Abstract
Methods and devices provide for a dynamic bias voltage control in detector photodiodes. The methods and systems use a bias control loop to make continuous detections of changes in the effective breakdown current of the detector photodiodes, thereby enabling the devices to change the bias voltage as needed. In one embodiment, a sense diode is added and operated at the breakdown current while the detector diode is operated at a small offset from the breakdown current. As performance conditions change, a feedback loop with the sense diode detects changes in the breakdown current and is used to adjust the bias voltage as necessary. In another embodiment, no sense diode is used. Rather, the detector diode itself is maintained at the breakdown current by a low frequency feedback loop. The optical signal is measured by a high frequency filter.