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:
Jun. 30, 2009
Filed:
Nov. 27, 2003
Hindrick Freerk Bulthuis, Edinburgh, GB;
Frederick Marcel Van Der Vliet, Pasadena, CA (US);
Gunter Beelen, Zoutleeuw, BE;
Jamie Suarez Pandavenes, Oviede, ES;
Hindrick Freerk Bulthuis, Edinburgh, GB;
Frederick Marcel van der Vliet, Pasadena, CA (US);
Gunter Beelen, Zoutleeuw, BE;
Jamie Suarez Pandavenes, Oviede, ES;
Gemfire Europe Limited, Livingston, GB;
Abstract
An optical branching component particularly suitable for use as a tap device is described. The component has two optical waveguides coupled between two optical couplers which each include at least one MMI supporting at least two guided modes. There is an effective optical path length difference between the two waveguides and the coupling strength of at least one of the couplers monotonically decreases with increasing wavelength in the operational wavelength region of the component. This means a coupler with relatively large coupling strength and relatively low polarization dependency can be used in the component, giving low polarization dependent variation in the tap ratio, particularly for small tap ratios. Moreover, the use of MMIs in the couplers avoids the need to fabricate to a high process tolerance very small gaps between two waveguides, as can be the case with directional couplers used in prior art branching component designs.