Widely Applied Mathematics Seminar
November 14, 2024
2 - 3pm
Maxwell Dworkin 119

"Designer Scattering for Wave Control: Analytical Constraints to Computational Practice"
Steven G. Johnson, Massachusetts Institute of Technology


Abstract: The control of waves by thin designable scattering surfaces, from submicron-patterned optical "metasurfaces" to devices for microwave and acoustic waves, has been studied for a wide range of applications in communications, imaging and sensing. Designing and understanding the geometry and phase/amplitude response of such surfaces, composed of hundreds or even millions of scattering elements, becomes more and more difficult at broader bandwidths and for more ambitious applications (e.g. involving complex inference and signal processing tasks).

In this talk, we will discuss advances in the design and implementation of such surfaces. Computationally, this includes large-scale and topology optimization of multi-resonant metasurfaces for applications in imaging, filtering and sensing, even co-optimized end-to-end with post-processing analysis of the raw sensor readings.  Theoretically, developments in scattering theory have led both to new constraints on the attainable performance and theoretical criteria for resonance properties that lead back into device designs.

Speaker Bio: Steven G. Johnson is Professor of Applied Mathematics at the Massachusetts Institute of Technology, where he joined the faculty in 2004, with a joint appointment in the Department of Physics at MIT. He received his Ph.D. in physics from MIT in 2001, where he was also an undergraduate student (receiving B.S. degrees in physics, mathematics, and EECS in 1995). He works on the influence of complex geometries (particularly in the nanoscale) on the solutions of partial differential equations, especially for wave phenomena and electromagnetism. This includes analytical theory, numerics, and design of devices and phenomena. He is also known for his work in computational science, including both algorithmic advances and popular software packages, such as his development of the FFTW fast Fourier transform library (for which he co-received the 1999 J. H. Wilkinson Prize for Numerical Software) and the Meep and MPB software for electromagnetic simulation. 

Host: Nick Trefethen