Vikram Radhakrishnan

PhD Student

Nonlinear Control of Adaptive Optics for Exoplanet Imaging

Adaptive Optics -- Exoplanets -- Coronagraphy -- Nonlinear Control -- Machine Learning

Current Research Summary:

This research aims at the dedicated shaping of the stellar PSF in an exoplanet imager to create an image-plane dark area at the position of an exoplanet. In this approach, we do not distinguish between the role of the coronagraph and AO. Instead we treat the combined system as an adaptive coronagraph, where the coronagraph imposes a static phase addition on the wavefront, and the AO system imposes dynamic phase additions with closed-loop feedback from the wavefront sensor measurements and periodic updates from the focal plane imaging camera. This direct, nonlinear approach of minimization of stellar light at the exoplanet's position will significantly enhance the achievable contrast of exoplanet imagers by correcting all remaining wavefront aberrations and component imperfections.

Prior Research:

Master's degree in Astronomy and Instrumentation at Leiden University (2015-2017)