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. 23, 2003
Filed:
Dec. 21, 2001
Marshall Thomas DePue, San Mateo, CA (US);
Shalini Venkatesh, Santa Clara, CA (US);
Hisato Uetsuka, Hitachi, JP;
Hiroaki Okano, Hitachi, JP;
Other;
Abstract
An optical switching apparatus and a method of efficiently switching optical signals are disclosed. Optical insertion loss may be reduced in a planar lightwave circuit by determining an optimal spacing between perturbations including using passive perturbations, having a three dimensional refractive index distribution, in an array of waveguides, or by adjusting parameters of existing perturbations e.g. their spacing. The perturbation and each waveguide have different three dimensional refractive index distributions. The perturbation may be positioned anywhere in the array of waveguides. The perturbation may be a trench, a region of refractive index different from that in each waveguide, a broken waveguide core, or a modification of the topography of the array of waveguides. In one embodiment, the perturbation is a periodic or quasiperiodic perturbation.