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. 02, 2002
Filed:
Aug. 04, 2000
Daniel Levner, Toronto, Ontario, CA;
Martin F. Fay, Toronto, Ontario, CA;
Jingming Xu, Providence, RI (US);
Other;
Abstract
The present invention relates to a method for synthesizing supergratings using Fourier analysis. The method divides the synthesis process into two stages: synthesis of an “analog” grating profile, followed by a quantization step. The method provides a generalized procedure for analog synthesis by drawing on the Fourier approximation and on finite-inpulse-response (FIR) filter design theory, while it interprets the simple threshold quantization as a “zeroth order” Delta-Sigma Modulator, which it improves. The method of designing a supergrating for a waveguide includes providing a reflectance spectrum in at least one spectral band to be produced by a supergrating in a waveguide, the reflectance spectrum having specified reflectance features, transforming the reflectance spectrum to a Fourier domain representation having Fourier-domain features, computationally synthesizing an analog refractive index profile corresponding to the Fourier-domain representation and transforming the analog refractive index profile to a binary or multi-level refractive index profile representation in such a way as to conserve Fourier-domain information within the spectral band.