# US 7,609,934 B2 · Integrated tunable optical equalizer > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 7,609,934 B2 - Document ID: US7609934B2 - Status: Granted - Kind: B2 - Application number: 12/055,115 - Filed: 2008-03-25 - Published: 2009-10-01 - Granted: 2009-10-27 - Earliest claimed: 2008-03-25 - Assignees: Alcatel-Lucent USA Inc. - Inventors: Christopher Richard Doerr - Web page: https://patentgrep.com/patent/US7609934B2 ## CPC - G02F 1/2955: {by controlled diffraction or phased-array beam steering (controlled diffraction for optical waveguide switching G02F1/313)} - B82Y 20/00: Nanooptics, e.g. quantum optics or photonic crystals - G02B 6/12011: {characterised by the arrayed waveguides, e.g. comprising a filled groove in the array section} - G02B 6/12033: {characterised by means for configuring the device, e.g. moveable element for wavelength tuning (switching G02B6/35; thermo-optic devices G02F1/0147)} - H04B 10/25133: {including a lumped electrical or optical dispersion compensator (H04B10/2519, H04B10/2525 takes precedence)} - G02F 1/0147: {based on thermo-optic effects (G02F1/132 takes precedence)} - G02F 1/0155: {modulating the optical absorption} - G02F 1/0156: {using free carrier absorption} - G02F 1/01708: {in an optical wavequide structure} - G02F 1/3133: {the optical waveguides being made of semiconducting materials} - G02F 2201/12: electrode - G02F: OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS - B82Y: SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES - G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS - H04B: TRANSMISSION ## Abstract Provided is an apparatus and method for use thereof. The apparatus, in one embodiment, includes first and second 1×N couplers integrated on a substrate and configured to receive an optical symbol having an intended time slot, N being at least three. The apparatus, in this embodiment, further includes N waveguide arms integrated on the substrate, having modulators and coupled between the first and second 1×N couplers. The apparatus, in this embodiment, additionally, includes a modulator controller configured to drive the modulators such that, following transmission over a distance, components of the optical symbol outside of the intended time slot are attenuated relative to components within the intended time slot. ## Claims ### Claim 1 An apparatus, comprising: first and second 1×N couplers integrated on a substrate and configured to receive an optical symbol having an intended time slot, N being at least three; N waveguide arms integrated on the substrate, having modulators and coupled between the first and second 1×N couplers; and a modulator controller configured to drive the modulators such that, following transmission over a distance, components of the optical symbol outside of the intended time slot are attenuated relative to components within the intended time slot. ### Claim 2 (depends on 1) The apparatus of claim 1 wherein the intended time slot is a central lobe of the optical symbol, and further wherein the modulator controller is configured to drive the modulators such that, following transmission over the distance, side lobes and a central lobe of the optical symbol are attenuated relative to one another. ### Claim 3 (depends on 2) The apparatus of claim 2 wherein the modulator controller is configured to drive the modulators to transfer energy between the central lobe and the side lobes. ### Claim 4 (depends on 3) The apparatus of claim 3 further including a transmitter integrated on the substrate, and further wherein the modulator controller is configured to create the side lobes by transferring energy from the central lobe. ### Claim 5 (depends on 4) The apparatus of claim 4 wherein the side lobes created by the modulator controller are more than 90° out of phase with respect to the central lobe. ### Claim 6 (depends on 4) The apparatus of claim 4 further including a data modulator integrated on the substrate between a light source and the first 1×N coupler. ### Claim 7 (depends on 4) The apparatus of claim 4 further including a feedback controller configured to provide feedback information from the optical symbol having been transmitted over the distance to the modulator controller to adjust an amplitude or phase of the side lobes being created. ### Claim 8 (depends on 3) The apparatus of claim 3 further including a receiver integrated on the substrate, and further wherein the modulator controller is configured to transfer the energy from the side lobes. ### Claim 9 (depends on 8) The apparatus of claim 8 wherein the modulator controller transfers at least a portion of the energy to the central lobe. ### Claim 10 (depends on 1) The apparatus of claim 1 wherein an optical pathlength of each of the N waveguide arms is different. ### Claim 11 (depends on 1) The apparatus of claim 1 wherein optical pathlengths of the N waveguide arms sequentially change by a fixed amount ΔL. ### Claim 12 (depends on 11) The apparatus of claim 11 wherein the fixed amount ΔL is less than a bit period of the optical symbol. ### Claim 13 (depends on 1) The apparatus of claim 1 wherein the first and second 1×N couplers have a power splitting distribution that is highest for a center most waveguide arm. ### Claim 14 (depends on 1) The apparatus of claim 1 wherein the N waveguide arms include a center most waveguide arm and one or more opposing pairs of side waveguide arms, and further wherein the modulators are associated with the one or more pairs of side waveguide arms. ### Claim 15 (depends on 14) The apparatus of claim 14 wherein each side waveguide arm has a modulator associated therewith. ### Claim 16 (depends on 14) The apparatus of claim 14 wherein each side waveguide arm has two or more modulators associated therewith. ### Claim 17 (depends on 1) The apparatus of claim 1 wherein the modulators are electro-optic modulators. ### Claim 18 (depends on 17) The apparatus of claim 17 wherein ones of the electro-optic modulators are configured to be forward biased to get primarily phase modulation or are configured to be reverse biased to get primarily amplitude modulation. ### Claim 19 (depends on 18) The apparatus of claim 18 such that at least one waveguide arm has two modulators, one acting as a phase modulator and one as an amplitude modulator. ### Claim 20 (depends on 17) The apparatus of claim 17 wherein ones of the electro-optic modulators are configured to be forward biased to get amplitude modulation via free-carrier absorption. ### Claim 21 (depends on 17) The apparatus of claim 17 wherein ones of the modulators are thermooptic modulators to get primarily phase modulation. ### Claim 22 (depends on 1) The apparatus of claim 1 wherein each waveguide arm contains at least one modulator. ### Claim 23 (depends on 1) The apparatus of claim 1 wherein the first and second 1×N couplers are star couplers. ### Claim 24 (depends on 1) The apparatus of claim 1 wherein the first or second 1×N couplers are not even splitting couplers.