CAM Colloquium: Jeffrey Jewell (NASA Jet Propulsion Laboratory) - Optical coronagraph design for the direct imaging of habitable zone exoplanets

Description

Abstract:
The goal of directly imaging Earth-like planets in the habitable zone of other stars in our galaxy (potentially supporting life?!) has motivated the design of high-contrast imaging instruments for use with large segmented aperture space telescopes. The host star is 10 billion times brighter than the planet in reflected light, making the planet undetectable without extreme suppression of diffracted starlight. Optical instruments such as coronagraphs are able to create an "eclipse" of the star while allowing planet light to pass through to detectors. Finding ideal coronagraph designs with standard optical elements involves a challenging non-convex optimization problem with a nonlinear dependence on control degrees of freedom.

In this talk, I will review Fourier optics and the numerical simulation of coronagraphs, and discuss algorithms for their design optimization. I will also discuss a Hilbert space perspective on theoretically ideal coronagraphs as linear operators resulting in maximal planet light throughput while completely suppressing the diffracted starlight. In principle, these ideal coronagraph linear operators can be implemented with advanced photonic integrated circuits being developed for both optical and quantum computing.

Bio:
Dr. Jeffrey Jewell is a cosmologist and data scientist at the NASA Jet Propulsion Laboratory, and a Caltech External Affiliate in the department of Applied Physics. He received a B.S. in Physics from MIT, and Ph.D. in astrophysics from the University of Chicago. Following his Ph.D. in August 2000, he came to NASA JPL and developed Bayesian approaches to the analysis of the cosmic microwave background observations returned from the European Space Agency and NASA joint Planck mission. His current research is focused on algorithmic development for next generation space-based cosmology missions, computational methods for nonlinear partial differential equations (encountered in modified theories of gravity), and additionally technology development for future direct imaging exoplanet missions, including optical instrument design optimization and methods of wavefront sensing and closed-loop control.