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US 6,657,786 B2Granted
Synthesis of supergratings by fourier methods
AssigneeDigital LightCircuits, Inc.
InventorsDaniel Levner, Martin F. Fay, Jingming Xu
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AssigneeDigital LightCircuits, Inc.
InventorsDaniel Levner, Martin F. Fay, Jingming Xu
Estimating the term…
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-impulse-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.
A method for designing a waveguide supergrating, the method comprising:
A method for designing a waveguide supergrating, the method comprising:
A method for designing a waveguide supergrating, the method comprising:
A waveguide comprising at least one supergrating, wherein the at least one supergrating exhibits refractive properties according to at least one effective refractive index profile corresponding to a specified reflectance spectrum in at least one spectral band, the at least one effective refractive index profile substantially corresponding to a quantization of an analog index profile, wherein the quantization substantially conserves Fourier-domain information within said at least one spectral band.
A waveguide comprising at least one supergrating. wherein the at least one supergrating exhibits refractive properties according to at least one effective refractive index profile corresponding to a specified reflectance spectrum in at least one spectral band, the at least one effective refractive index profile substantially corresponding to a quantization of an analog index profile, wherein the quantization substantially conserves Fourier-domain information within said at least one spectral band wherein the at least one effective refractive index profile corresponding to the quantization of the analog index profile further comprises the at least one effective refractive index profile corresponding to a Delta Sigma Modulation quantization of an analog index profile.
A program storage device readable by a machine, tangibly embodying a program of instructions executable by the machine to perform a method for designing a waveguide. supergrating, said method comprising:
A method for designing a waveguide supergrating, the method comprising:
A program storage device readable by a machine, tangibly embodying a program of instructions executable by the machine to perform a method for designing a waveguide supergrating, said method comprising:
Dependencies are inferred from the claim text.