Raphaël Pestourie, PhD

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Welcome!

I am a Postdoctoral Associate of Prof. Steven G. Johnson's group in the Mathematics Department of the Massachusetts Institute of Technology (MIT). I research towards a new paradigm for inverse design of metamaterials by combining approximate numerical solvers, (Bayesian and scientific) machine learning techniques, and end-to-end optimization. My work is multidisciplinary and experiment-driven on a wide range of applications: mostly optics, but also mechanics, quantum computing, paper crumpling theory, and the Boltzmann equation. I am interested in collaborative, interdisciplinary problems where research outcomes are larger than the mere sum of the contributions from each discipline. My philosophy is to develop methods through impactful applications rather than focusing on methods development alone.

News

November 2021: I was invited to present at OPTICSMEET2021 on Saturday November 6th. My virtual presentation will be about a new paradigm for surrogate-based inverse design in nanophotonics, leveraging AI to go beyond the locally periodic approximation.

November 2021: Surrogate-based inverse design meets end-to-end optimization. We discovered spontaneous multiplexing when combining large-scale metasurface design and Tikhonov regularization for multi-channel imaging (spectral, polarization and depth), end-to-end. Check it out on arXiv.

September 2021: Excited to talk about "Extreme Optics: Inverse Design and Experimental Realizations of Ultra-Large-Area Complex Meta-Optics" at the 15th International Congress on Artificial Materials for Novel Wave Phenomena - Metamaterials 2021

September 2021: Our paper Inverse Designed Extended Depth of Focus Meta-Optics for Broadband Imaging in the Visible was accepted in the journal Nanophotonics.

August 2021: Our paper "Physics-informed neural networks with hard constraints for inverse design" was accepted in SIAM Journal on Scientific Computing.

August 2021: Excited to talk at SPIE Optics and Photonics in the session on Deep Learning in Photonics in San Diego, CA!

July 2021: I just pushed the supporting code of my active learning article in npj Computational Materials. It is part of the IBM open source project on uncertainty quantification called UQ360.

June 2021: Excited to talk at the OSA Optical Design and Fabrication Congress about complex design of metasurfaces.

May 2021: Our work on surrogate models for PDEs was features on IBM blog AI boosts the discovery of metamaterials vital for next-gen gadgets.

May 2021: I will be presenting on "Inverse Design of Complex Meta-Optics" on May 13th at the Boston Chapter of the IEEE Photonic Society. Thank you for the invitation!

May 2021: We put on arXiv our latest work on lenses with Extended Depth of Field. Check it out! Inverse Designed Extended Depth of Focus Meta-Optics for Broadband Imaging in the Visible.

April 2021: We put on arXiv the fruit of a multiple year collaboration culminating in the larger metasurface in the visible to date (cm diameter)! Check it out Inverse design enables large-scale high-performance meta-optics reshaping virtual reality.

April 2021: Our paper "Active learning of deep surrogates for PDEs", where we extend our work previous in active learning to mechanical elasticity equations, was accepted at ICLR 2021 Workshop on Deep Learning for Simulation! I am looking forward to sharing this work with the community on May 7th!

March 2021: Excited to give a seminar "Efficient inverse design for extreme applications in optics" in the Instituto de Ingeniería Matemática y Computacional at Pontificia Universidad Católica de Chile!

February 2021: Our paper "Physics-informed neural networks (PINN) with hard constraints for inverse design" is now available on arXiv. It presents PINN used in inverse design, especially enforcing the PDE constraint via an augmented Lagrangian method. The advantage of this approach is that the resulting designs are smoother.

December 2020: Our paper "End-to-end nanophotonic inverse design for imaging and polarimetry." is available ahead of print in Nanophotonics .

December 2020: Excited to have been invited to present my research "Inverse design and deep learning for optical metasurfaces" for the groups of Prof. Boubacar Kanté and Prof. Eli Yablonovitch at UC Berkeley.

October 2020: npj Computation Materials published my collaboration with MIT-IBM Watson AI lab Active learning of deep surrogates for PDEs: application to metasurface design on October 29, 2020.

October 2020: I presented the poster "Active learning of deep surrogates for PDEs: Application to metasurface design" at the AI for Materials: From Discovery to Production symposium organised by the New York Academy of Sciences, on October 6, 2020.

August 2020: I just put on arXiv this fantastic work on active learning for PDE surrogate models done in collaboration with MIT-IBM lab. Using our active-learning algorithm, we can find the training points that make the biggest difference with respect to model accuracy improvement, thus reducing the need for data by more than an order of magnitude! The surrogate model is 100x faster than solving the PDE directly. Active learning of deep surrogates for PDEs: Application to metasurface design

June 2020: We just pushed an exciting ground-breaking article on arXiv about new usage of large-scale optimization for inverse design in nanophotonics "End-to-End Inverse Design for Inverse Scattering via Freeform Metastructures"

March 2020: ACS Photonics published my collaboration with Elyas Bayati and Arka Majumdar from UW of an inverse-designed lens with extended depth of field in 2D. Inverse designed metalenses with extended depth of focus

March 2020: L'Essentiel du Sup published an interview of me about the impact that multidisciplinarity has played in my student career as a dual degree student at ESSEC and École Centrale Paris (CentraleSupelec). Oser l'hybridation, de la théorie à la pratique

February 2020: I published a repository called fdfd_local_field on GitHub with julia code for embarassingly parallel simulations of Maxwell's equation in two dimensions. Github/rpestourie

January 2020: the 3rd Physics Informed Machine Learning Workshop in Santa Fe accepted my abstract "Active neural networks for electromagnetic surrogate models" about my current collaborative work with IBM Research. PIML 2020

December 2019: I defended my PhD in Applied Mathematics from Harvard John A. Paulson School of Engineering and Applied Sciences: "Assume Your Neighbor is Your Equal: Inverse Design in Nanophotonics" (available at Harvard University Library systems).

October 2019: Elyas Bayati and I pushed the first experimental application designed by my optimization framework-–a 2D lens with extended depth of field on arXiv. Inverse designed metalenses with extended depth of focus

May 2019: I presented an extension of my large-scale optimization framework to three dimensional applications at 2019 IEEE MTT-S International Conference on Numerical Electromagnetic and Multiphysics Modeling and Optimization. NEMO 2019

May 2019: I was interviewed by Jennifer Chu from MIT News Office to vulgarize my research. Mathematical technique quickly tunes next-generation lenses

May 2019: Optics Express published the extension of my optimization framework to topology optimization. Topology optimization of freeform large-area metasurfaces

March 2019: I defended my PhD secondary field in Computational Science and Engineering: "Hybrid Maxwell’s equations solver and inverse design tool for metasurfaces".

January 2019: I was invited to present my paper "Inverse design of large-area metasurfaces" at the Workshop on Numerical Analysis of Partial Differential Equations in Concepción, Chile. WONAPDE 2019

December 2018: Optics Express published my seminal paper about large-scale optimization of metasurfaces based on the local periodic approximation. Inverse design of large-area metasurfaces

November 2018: Optics Express published a study that my colleague Carlos Pérez-Arancibia conducted with me and Prof Steven G. Johnson about a locally periodic approximation for continuous surfaces. Sideways adiabaticity: beyond ray optics for slowly varying metasurfaces


Publications

Pre-prints:

R. Pestourie, Y. Mroueh, C. Rackauckas, P. Das, and S.G. Johnson. "Physics-enhanced deep surrogates for PDEs," (November 2021) [arXiv]


Z. Lin, R. Pestourie, C. Roques-Carmes, Z. Li, F. Capasso, M. Soljačić, and S. G. Johnson. "End-to-end metasurface inverse design for single-shot multi-channel imaging," (November 2021). [arXiv]


Z. Li*, R. Pestourie*, J-S. Park, Y-W. Huang, S. G. Johnson, and F. Capasso. "Inverse design enables large-scale high-performance meta-optics reshaping virtual reality," (April 2021). [arXiv]



Peer-reviewed articles:

E. Bayati*, R. Pestourie*, S. Colburn, Z. Lin, S. G. Johnson, and A. Majumdar. "Inverse Designed Extended Depth of Focus Meta-Optics for Broadband Imaging in the Visible," Nanophotonics 1, 20210431 (September 2021). [DOI | arXiv]


L. Lu, R. Pestourie, W. Yao, Z. Wang, F. Verdugo, and S. G. Johnson "Physics-informed neural networks with hard constraints for inverse design," in press SIAM Journal on Scientific Computing (2021). [arXiv]

Z. Lin, C. Roques-Carmes, R. Pestourie, M. Soljačić, A. Majumdar, and S. G. Johnson. "End-to-end nanophotonic inverse design for imaging and polarimetry," Nanophotonics 1, 20200579 (October 2020). [DOI | arXiv]

R. Pestourie, Y. Mroueh, T. V. Nguyen, P. Das, S. G. Johnson, "Active learning of deep surrogates for PDEs: Application to metasurface design," npj Computational Materials (October 2020). [DOI | arXiv | PDF]

E. Bayati*, R. Pestourie*, S. Colburn, Z. Lin, S. G. Johnson, and A. Majumdar, “Inverse designed metalenses with extended depth of focus,” ACS Photonics 2020 7 (4), 873-878 (March 2020). [ DOI | arXiv ]

Z. Lin, V. Liu, R. Pestourie, and S. G. Johnson, “Topology optimization of freeform large-area metasurfaces,” Optics Express, vol. 27, pp. 15765–15775 (May 2019). [ DOI | arXiv ]

R. Pestourie, C. Pérez-Arancibia, Z. Lin, W. Shin, F. Capasso, and S. G. Johnson, “Inverse design of large-area metasurfaces,” Optics Express, vol. 26, pp. 33732–33747 (December 2018). [ DOI | arXiv ]

C. Pérez-Arancibia, R. Pestourie, and S. G. Johnson, “Sideways adiabaticity: Beyond ray optics for slowly varying metasurfaces,” Optics Express, vol. 26, pp. 30202–30230 (November 2018). [ DOI | arXiv ]



Conference articles:

R. Pestourie, Z. Li, E. Bayati, J.-S. Park, Y.-W. Huang, S. Colburn, Z. Lin, A. Majumdar, F. Capasso, and S.G. Johnson "Extreme optics: inverse design and experimental realizations of ultra-large-area complex meta-optics" 15th International Congress on Artificial Materials for Novel Wave Phenomena - Metamaterials 2021


R. Pestourie and S. G. Johnson "Opening the black box for data efficiency and inverse design in photonics" International Society for Optics and Photonics - Metamaterials, Metadevices, and Metasystems 2021


R. Pestourie and S. G. Johnson "Complex design of metasurfaces" OSA Optical Design and Fabrication 2021 (Flat Optics, Freeform, IODC, OFT) (June 2021)


R. Pestourie, G. Chomette, Y. Mroueh, P. Das, R. Radovitzky, an S. G. Johnson, "Active learning of deep surrogates for PDEs," ICLR 2021 SimDL Workshop (May 2021). [PDF]


Patent:

R. Pestourie, Y. Mroueh, P. Das, S. G. Johnson "Active learning of data models for scaled optimization" US Patent 17/405318


PhD thesis:

My PhD thesis "Assume Your Neighbor is Your Equal: Inverse Design in Nanophotonics" will be available on Harvard University Library website after a two-year embargo in March 2022.



Featured in the news:

"AI boosts the discovery of metamaterials vital for next-gen gadgets," IBM blog (May 2021).


"Mathematical technique quickly tunes next-generation lenses," MIT News (May 2019).


Social media:

Follow me on Twitter @rpestouriePhD, on Google Scholar, or on ORCID.

Bio

Raphaël has been a Postdoctoral Associate at MIT Mathematics since 2020. Originally from France, Raphaël earned a dual degree between ESSEC Business School and École Centrale Paris. He also earned a Master’s of research in Nanosciences at Université Paris Saclay. In Prof. Xiang Zhang's lab at UC Berkley, he conducted his master’s research on metamaterials. Raphaël earned a PhD in Applied Mathematics with a Secondary Field in Computational Science and Engineering from Harvard University in 2020, originally as a fellow from Fulbright France. His PhD research was about inverse design for metasurfaces, and he was co-advised between Professors Federico Capasso at Harvard and Steven Johnson at MIT. While at Harvard, Raphaël also earned an AM in Statistics and completed significant coursework in data science and the Russian language. He served as a Resident Affiliate (2017-2021) and is now a Non-Resident Tutor (2021-present) with Quincy House at Harvard College, where he advises Harvard undergraduate students, as a primary academic advisor for some and informally for many.

Résumé

Resume_RaphaelPestourie.pdf

The whole is greater than the sum of the parts.

Wrongly attributed to Aristotle

Главное в физике ― это умение пренебрегать. [The most important part of doing physics is the knowledge of approximation.]

Lev Landau

It doesn’t matter how beautiful your theory is, it doesn’t matter how smart you are. If it doesn’t agree with experiment, it’s wrong.

Richard Feynman

Contact

MIT Mathematics

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