The Experts below are selected from a list of 67641 Experts worldwide ranked by ideXlab platform
Jelena Vuckovic - One of the best experts on this subject based on the ideXlab platform.
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Inverse Design of microresonator dispersion for nonlinear optics
Conference on Lasers and Electro-Optics, 2020Co-Authors: Geun Ho Ahn, Jinhie Skarda, Ki Youl Yang, Jelena VuckovicAbstract:Inverse Design optimizes microcavity structures for desired dispersion properties and fabrication constraints. We experimentally demonstrate robust control of cavity dispersion at the telecommunication band on foundry compatible photonic platform.
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nanophotonic Inverse Design with spins software architecture and practical considerations
Applied physics reviews, 2020Co-Authors: Dries Vercruysse, Neil V Sapra, Jinhie Skarda, Jan Petykiewicz, Jelena VuckovicAbstract:This paper presents a computational nanophotonic Design library for gradient-based optimization called the Stanford Photonic Inverse Design Software (SPINS). Borrowing the concept of computational graphs, SPINS is a Design framework that emphasizes flexibility and reproducible results. By factoring the Inverse Design process into components that can be swapped out for one another, SPINS enables Inverse Design practitioners to easily explore different Design methodologies. Here, we present the mathematical and architectural details on how to achieve these goals, using the Inverse Design of a wavelength demultiplexer as a primary example. Using Inverse Design effectively requires understanding the “control knobs” available to the Designer, and, to that end, we also discuss practical considerations and heuristics for effective use of Inverse Design. In particular, by running Inverse Design on hundreds of Designs of 3D wavelength demultiplexers, this paper explores the landscape of local minima, which leads to insights on the choice of initial conditions.
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nanophotonic Inverse Design with spins software architecture and practical considerations
arXiv: Applied Physics, 2019Co-Authors: Dries Vercruysse, Neil V Sapra, Jinhie Skarda, Jan Petykiewicz, Jelena VuckovicAbstract:A computational nanophotonic Design library for gradient-based optimization called SPINS is presented. Borrowing the concept of computational graphs, SPINS is a Design framework that emphasizes flexibility and reproducible results. The mathematical and architectural details to achieve these goals are presented, and practical considerations and heuristics for using Inverse Design are discussed, including the choice of initial condition and the landscape of local minima.
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analytical level set fabrication constraints for Inverse Design
Scientific Reports, 2019Co-Authors: Dries Vercruysse, Neil V Sapra, Rahul Trivedi, Jelena VuckovicAbstract:Inverse Design methods produce nanophotonic devices with arbitrary geometries that show high efficiencies as well as novel functionalities. Ensuring fabricability during optimization of these unrestricted device geometries is a major challenge for these Design methods. In this work, we construct a fabrication constraint penalty function for level set geometry representations of these devices. This analytical penalty function limits both the gap size and boundary curvature of a device. We incorporate this penalty in a fully automated optical Design flow using a quasi-Newton optimization method. The performance of our Design method is evaluated by Designing a series of waveguide demultiplexers (WDM) and mode converters with various footprints and minimum feature sizes. Finally, we Design and experimentally characterize three WDMs with a 80 nm, 120 nm and 160 nm feature size.
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waveguide integrated dielectric laser particle accelerators through the Inverse Design of photonics
Conference on Lasers and Electro-Optics, 2019Co-Authors: Neil V Sapra, Ki Youl Yang, Dries Vercruysse, Jelena VuckovicAbstract:We apply the Inverse Design methodology to waveguide-integrated dielectric laser particle accelerators. These accelerators are optimized to maximize the acceleration gradient. The Designs have been fabricated on a silicon-on-insulator platform and experimentally characterized. © 2019 The Author(s)
Ole Sigmund - One of the best experts on this subject based on the ideXlab platform.
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compact 200 line matlab code for Inverse Design in photonics by topology optimization tutorial
Journal of The Optical Society of America B-optical Physics, 2021Co-Authors: Rasmus E Christiansen, Ole SigmundAbstract:We provide a compact 200 line MATLAB code demonstrating how topology optimization (TopOpt) as an Inverse Design tool may be used in photonics, targeting the Design of two-dimensional dielectric metalenses and a metallic reflector as examples. The physics model is solved using the finite element method, and the code utilizes MATLAB’s fmincon algorithm to solve the optimization problem. In addition to presenting the code itself, we briefly discuss a number of extensions and provide the code required to implement some of these. Finally, we demonstrate the superiority of using a gradient-based method compared to a genetic-algorithm-based method (using MATLAB’s ga algorithm) for solving Inverse Design problems in photonics. The MATLAB software is freely available in the paper and may be downloaded from https://www.topopt.mek.dtu.dk.
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a 200 line matlab code for Inverse Design in photonics by topology optimization
arXiv: Mathematical Software, 2020Co-Authors: Rasmus E Christiansen, Ole SigmundAbstract:We provide a compact 200 line MATLAB code demonstrating how Topology Optimization (TopOpt) as an Inverse Design tool may be used in photonics, targeting the Design of two-dimensional dielectric metalenses and a metallic reflector as examples. The physics model is solved using the finite element method and the code utilizes MATLABs fmincon algorithm to solve the optimization problem. In addition to presenting the code itself, we briefly discuss a number of extensions and provide the code required to implement some of these. Finally, we demonstrate the superiority of using a gradient-based method compared to a genetic-algorithm-based method (using MATLABs ga algorithm) for solving Inverse Design problems in photonics. The MATLAB software is freely available in the paper and may be downloaded from https://www.topopt.dtu.dk.
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Inverse Design of nanoparticles for enhanced raman scattering
Optics Express, 2020Co-Authors: Rasmus E Christiansen, Ole Sigmund, Jerome Michon, Mohammed Benzaouia, Steven G JohnsonAbstract:We show that topology optimization (TO) of metallic resonators can lead to ∼102 × improvement in surface-enhanced Raman scattering (SERS) efficiency compared to traditional resonant structures such as bowtie antennas. TO Inverse Design leads to surprising structures very different from conventional Designs, which simultaneously optimize focusing of the incident wave and emission from the Raman dipole. We consider isolated metallic particles as well as more complicated configurations such as periodic surfaces or resonators coupled to dielectric waveguides, and the benefits of TO are even greater in the latter case. Our results are motivated by recent rigorous upper bounds to Raman scattering enhancement, and shed light on the extent to which these bounds are achievable.
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Inverse Design of nanoparticles for enhanced raman scattering
arXiv: Optics, 2019Co-Authors: Rasmus E Christiansen, Ole Sigmund, Jerome Michon, Mohammed Benzaouia, Steven G JohnsonAbstract:We show that topology optimization (TO) of metallic resonators can lead to $\sim 10^2\times$ improvement in surface-enhanced Raman scattering (SERS) efficiency compared to traditional resonant structures such as bowtie antennas. TO Inverse Design leads to surprising structures very different from conventional Designs, which simultaneously optimize focusing of the incident wave and emission from the Raman dipole. We consider isolated metallic particles as well as more complicated configurations such as periodic surfaces or resonators coupled to dielectric waveguides, and the benefits of TO are even greater in the latter case. Our results are motivated by recent rigorous upper bounds to Raman scattering enhancement, and shed light on the extent to which these bounds are achievable.
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Inverse Design engineering of all silicon polarization beam splitters
Proceedings of SPIE, 2016Co-Authors: Lars Hagedorn Frandsen, Ole SigmundAbstract:Utilizing the Inverse Design engineering method of topology optimization, we have realized high-performing all-silicon ultra-compact polarization beam splitters. We show that the device footprint of the polarization beam splitter can be as compact as ~2 μm2 while performing experimentally with a polarization splitting loss lower than ~0.82 dB and an extinction ratio larger than ~15 dB in the C-band. We investigate the device performance as a function of the device length and find a lower length above which the performance only increases incrementally. Imposing a minimum feature size constraint in the optimization is shown to affect the performance negatively and reveals the necessity for light to scatter on a sub-wavelength scale to obtain functionalities in compact photonic devices.
Rasmus E Christiansen - One of the best experts on this subject based on the ideXlab platform.
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compact 200 line matlab code for Inverse Design in photonics by topology optimization tutorial
Journal of The Optical Society of America B-optical Physics, 2021Co-Authors: Rasmus E Christiansen, Ole SigmundAbstract:We provide a compact 200 line MATLAB code demonstrating how topology optimization (TopOpt) as an Inverse Design tool may be used in photonics, targeting the Design of two-dimensional dielectric metalenses and a metallic reflector as examples. The physics model is solved using the finite element method, and the code utilizes MATLAB’s fmincon algorithm to solve the optimization problem. In addition to presenting the code itself, we briefly discuss a number of extensions and provide the code required to implement some of these. Finally, we demonstrate the superiority of using a gradient-based method compared to a genetic-algorithm-based method (using MATLAB’s ga algorithm) for solving Inverse Design problems in photonics. The MATLAB software is freely available in the paper and may be downloaded from https://www.topopt.mek.dtu.dk.
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a 200 line matlab code for Inverse Design in photonics by topology optimization
arXiv: Mathematical Software, 2020Co-Authors: Rasmus E Christiansen, Ole SigmundAbstract:We provide a compact 200 line MATLAB code demonstrating how Topology Optimization (TopOpt) as an Inverse Design tool may be used in photonics, targeting the Design of two-dimensional dielectric metalenses and a metallic reflector as examples. The physics model is solved using the finite element method and the code utilizes MATLABs fmincon algorithm to solve the optimization problem. In addition to presenting the code itself, we briefly discuss a number of extensions and provide the code required to implement some of these. Finally, we demonstrate the superiority of using a gradient-based method compared to a genetic-algorithm-based method (using MATLABs ga algorithm) for solving Inverse Design problems in photonics. The MATLAB software is freely available in the paper and may be downloaded from https://www.topopt.dtu.dk.
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Inverse Design of nanoparticles for enhanced raman scattering
Optics Express, 2020Co-Authors: Rasmus E Christiansen, Ole Sigmund, Jerome Michon, Mohammed Benzaouia, Steven G JohnsonAbstract:We show that topology optimization (TO) of metallic resonators can lead to ∼102 × improvement in surface-enhanced Raman scattering (SERS) efficiency compared to traditional resonant structures such as bowtie antennas. TO Inverse Design leads to surprising structures very different from conventional Designs, which simultaneously optimize focusing of the incident wave and emission from the Raman dipole. We consider isolated metallic particles as well as more complicated configurations such as periodic surfaces or resonators coupled to dielectric waveguides, and the benefits of TO are even greater in the latter case. Our results are motivated by recent rigorous upper bounds to Raman scattering enhancement, and shed light on the extent to which these bounds are achievable.
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Inverse Design of nanoparticles for enhanced raman scattering
arXiv: Optics, 2019Co-Authors: Rasmus E Christiansen, Ole Sigmund, Jerome Michon, Mohammed Benzaouia, Steven G JohnsonAbstract:We show that topology optimization (TO) of metallic resonators can lead to $\sim 10^2\times$ improvement in surface-enhanced Raman scattering (SERS) efficiency compared to traditional resonant structures such as bowtie antennas. TO Inverse Design leads to surprising structures very different from conventional Designs, which simultaneously optimize focusing of the incident wave and emission from the Raman dipole. We consider isolated metallic particles as well as more complicated configurations such as periodic surfaces or resonators coupled to dielectric waveguides, and the benefits of TO are even greater in the latter case. Our results are motivated by recent rigorous upper bounds to Raman scattering enhancement, and shed light on the extent to which these bounds are achievable.
Alexander Y. Piggott - One of the best experts on this subject based on the ideXlab platform.
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Inverse Design in nanophotonics
Nature Photonics, 2018Co-Authors: Sean Molesky, Zin Lin, Alexander Y. Piggott, Jelena Vuckovic, Weiliang Jin, Alejandro W RodriguezAbstract:Recent advancements in computational Inverse-Design approaches — algorithmic techniques for discovering optical structures based on desired functional characteristics — have begun to reshape the landscape of structures available to nanophotonics. Here, we outline a cross-section of key developments in this emerging field of photonic optimization: moving from a recap of foundational results to motivation of applications in nonlinear, topological, near-field and on-chip optics.Starting with a desired optical output it is possible to use computational algorithms to Inverse Design devices. The approach is reviewed here with an emphasis on nanophotonics.
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Inverse Design and demonstration of broadband grating couplers
arXiv: Applied Physics, 2018Co-Authors: Neil V Sapra, Alexander Y. Piggott, Ki Youl Yang, Dries Vercruysse, Jinhie Skarda, Jelena VuckovicAbstract:We present a gradient-based optimization strategy to Design broadband grating couplers. Using this method, we are able to reach, and often surpass, a user-specified target bandwidth during optimization. The Designs produced for 220 nm silicon-on-insulator are capable of achieving 3 dB bandwidths exceeding 100 nm while maintaining central coupling efficiencies ranging from -3.0 dB to -5.4 dB, depending on partial-etch fraction. We fabricate a subset of these structures and experimentally demonstrate gratings with 3 dB bandwidths exceeding 120 nm. This Inverse Design approach provides a flexible Design paradigm, allowing for the creation of broadband grating couplers without requiring constraints on grating geometry.
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outlook for Inverse Design in nanophotonics
arXiv: Optics, 2018Co-Authors: Sean Molesky, Zin Lin, Alexander Y. Piggott, Jelena Vuckovic, Weiliang Jin, Alejandro W RodriguezAbstract:Recent advancements in computational Inverse Design have begun to reshape the landscape of structures and techniques available to nanophotonics. Here, we outline a cross section of key developments at the intersection of these two fields: moving from a recap of foundational results to motivation of emerging applications in nonlinear, topological, near-field and on-chip optics.
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fabrication constrained nanophotonic Inverse Design
Scientific Reports, 2017Co-Authors: Alexander Y. Piggott, Jan Petykiewicz, Jelena VuckovicAbstract:A major difficulty in applying computational Design methods to nanophotonic devices is ensuring that the resulting Designs are fabricable. Here, we describe a general Inverse Design algorithm for nanophotonic devices that directly incorporates fabrication constraints. To demonstrate the capabilities of our method, we Designed a spatial-mode demultiplexer, wavelength demultiplexer, and directional coupler. We also Designed and experimentally demonstrated a compact, broadband 1 × 3 power splitter on a silicon photonics platform. The splitter has a footprint of only 3.8 × 2.5 μm, and is well within the Design rules of a typical silicon photonics process, with a minimum radius of curvature of 100 nm. Averaged over the Designed wavelength range of 1400–1700 nm, our splitter has a measured insertion loss of 0.642 ± 0.057 dB and power uniformity of 0.641 ± 0.054 dB.
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fabrication constrained nanophotonic Inverse Design
arXiv: Optics, 2016Co-Authors: Alexander Y. Piggott, Jan Petykiewicz, Jelena VuckovicAbstract:A major difficulty in applying computational Design methods to nanophotonic devices is ensuring that the resulting Designs are fabricable. Here, we describe a general Inverse Design algorithm for nanophotonic devices that directly incorporates fabrication constraints. To demonstrate the capabilities of our method, we Designed a spatial-mode demultiplexer, wavelength demultiplexer, and directional coupler. We also Designed and experimentally demonstrated a compact, broadband $1 \times 3$ power splitter on a silicon photonics platform. The splitter has a footprint of only $3.8 \times 2.5~\mathrm{\mu m}$, and is well within the Design rules of a typical silicon photonics process, with a minimum radius of curvature of $100~\mathrm{nm}$. Averaged over the Designed wavelength range of $1400 - 1700~\mathrm{nm}$, our splitter has a measured insertion loss of $0.642 \pm 0.057 ~\mathrm{dB}$ and power uniformity of $0.641 \pm 0.054~\mathrm{dB}$.
Jan Petykiewicz - One of the best experts on this subject based on the ideXlab platform.
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nanophotonic Inverse Design with spins software architecture and practical considerations
Applied physics reviews, 2020Co-Authors: Dries Vercruysse, Neil V Sapra, Jinhie Skarda, Jan Petykiewicz, Jelena VuckovicAbstract:This paper presents a computational nanophotonic Design library for gradient-based optimization called the Stanford Photonic Inverse Design Software (SPINS). Borrowing the concept of computational graphs, SPINS is a Design framework that emphasizes flexibility and reproducible results. By factoring the Inverse Design process into components that can be swapped out for one another, SPINS enables Inverse Design practitioners to easily explore different Design methodologies. Here, we present the mathematical and architectural details on how to achieve these goals, using the Inverse Design of a wavelength demultiplexer as a primary example. Using Inverse Design effectively requires understanding the “control knobs” available to the Designer, and, to that end, we also discuss practical considerations and heuristics for effective use of Inverse Design. In particular, by running Inverse Design on hundreds of Designs of 3D wavelength demultiplexers, this paper explores the landscape of local minima, which leads to insights on the choice of initial conditions.
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nanophotonic Inverse Design with spins software architecture and practical considerations
arXiv: Applied Physics, 2019Co-Authors: Dries Vercruysse, Neil V Sapra, Jinhie Skarda, Jan Petykiewicz, Jelena VuckovicAbstract:A computational nanophotonic Design library for gradient-based optimization called SPINS is presented. Borrowing the concept of computational graphs, SPINS is a Design framework that emphasizes flexibility and reproducible results. The mathematical and architectural details to achieve these goals are presented, and practical considerations and heuristics for using Inverse Design are discussed, including the choice of initial condition and the landscape of local minima.
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fabrication constrained nanophotonic Inverse Design
Scientific Reports, 2017Co-Authors: Alexander Y. Piggott, Jan Petykiewicz, Jelena VuckovicAbstract:A major difficulty in applying computational Design methods to nanophotonic devices is ensuring that the resulting Designs are fabricable. Here, we describe a general Inverse Design algorithm for nanophotonic devices that directly incorporates fabrication constraints. To demonstrate the capabilities of our method, we Designed a spatial-mode demultiplexer, wavelength demultiplexer, and directional coupler. We also Designed and experimentally demonstrated a compact, broadband 1 × 3 power splitter on a silicon photonics platform. The splitter has a footprint of only 3.8 × 2.5 μm, and is well within the Design rules of a typical silicon photonics process, with a minimum radius of curvature of 100 nm. Averaged over the Designed wavelength range of 1400–1700 nm, our splitter has a measured insertion loss of 0.642 ± 0.057 dB and power uniformity of 0.641 ± 0.054 dB.
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fabrication constrained nanophotonic Inverse Design
arXiv: Optics, 2016Co-Authors: Alexander Y. Piggott, Jan Petykiewicz, Jelena VuckovicAbstract:A major difficulty in applying computational Design methods to nanophotonic devices is ensuring that the resulting Designs are fabricable. Here, we describe a general Inverse Design algorithm for nanophotonic devices that directly incorporates fabrication constraints. To demonstrate the capabilities of our method, we Designed a spatial-mode demultiplexer, wavelength demultiplexer, and directional coupler. We also Designed and experimentally demonstrated a compact, broadband $1 \times 3$ power splitter on a silicon photonics platform. The splitter has a footprint of only $3.8 \times 2.5~\mathrm{\mu m}$, and is well within the Design rules of a typical silicon photonics process, with a minimum radius of curvature of $100~\mathrm{nm}$. Averaged over the Designed wavelength range of $1400 - 1700~\mathrm{nm}$, our splitter has a measured insertion loss of $0.642 \pm 0.057 ~\mathrm{dB}$ and power uniformity of $0.641 \pm 0.054~\mathrm{dB}$.
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Inverse Design and implementation of a wavelength demultiplexing grating coupler
Conference on Lasers and Electro-Optics, 2015Co-Authors: Alexander Y. Piggott, Jan Petykiewicz, Jesse Lu, Thomas M Babinec, Konstantinos G Lagoudakis, Jelena VuckovicAbstract:We have developed a general Inverse Design algorithm for Designing micro- and nano-photonic devices, where the user only specifies the desired device performance. We experimentally demonstrate a vertical-incidence wavelength demultiplexing grating Designed by this algorithm.
