Brown University

Other

Digital Lightcircuits, Inc.

Martin F Fay

Daniel Levner

Jingming Xu

Jeffrey N Weiss

Jonathan C Bloch

Optical gratings that perform a number of functions at various wavelengths are formed by various methods that preserve spectral information within a wavelength band, the functions including: coupling radiation from one waveguide () to another (), controllable gratings that operate on different wavelengths in response to external control signals.

Method and apparatus for detecting multiple optical wave lengths

Optical gratings that perform a number of functions at various wavelengths are formed by various methods that preserve spectral information within a wavelength band, the functions including: coupling radiation from one waveguide to another, controllable gratings that operate on different wavelengths in response to external control signals.

Method and apparatus for detecting multiple optical wavelengths

An optical component including at least one optical supergrating is provided. The optical supergrating includes a quantized refractive index profile adapted to exhibit a finite plurality of refractive indexes; which in turn are adapted to generate a reflectance spectrum in at least one spectral band corresponding to a Fourier transformed analog refractive index profile.

Method and apparatus for processing optical signals with supergratings

An optical waveguide has a surface. An array of separately actuated bodies is disposed proximal to the exposed surface, and an actuator separately actuates at least some of the bodies to change a spectral characteristic of a wave propagating through the waveguide. Preferably, the bodies are metal striplines, an electro-optical material is disposed between the striplines and the exposed surface, and the actuator is a CMOS chip that imposes a voltage to some or all of the lines. The voltage changes the refractive index at the interface with the surface, changing an index of refraction profile of the waveguide and effectively imposing a grating. Alternatively, the bodies are micro-beams and the actuator, also controlled by a CMOS chip, separately moves each micro-beam into and out of proximity to the surface. The grating is programmable via the CMOS chip. The programmable gratings may be used to couple different waves in the same or different waveguides, and may act as Bragg gratings, binary supergratings, or multi-level supergratings.

Programmable optical grating device and method

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 &ldquo;analog&rdquo; 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 &ldquo;zeroth order&rdquo; 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.

Synthesis of supergratings by fourier methods

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 &ldquo;analog&rdquo; 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 &ldquo;zeroth order&rdquo; 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.

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Providence, RI, United States of America

Martin F Fay