Implementation and Characterization of the Vector Vortex Coronagraph on the SEAL Testbed

TL;DR

This paper details the implementation and testing of a vector vortex coronagraph on the SEAL testbed, aiming to improve high-contrast imaging techniques for exoplanet observation.

Contribution

It introduces a new coronagraphic branch on SEAL, compares its performance with Keck Observatory, and integrates simulations with real wavefront sensor data for enhanced analysis.

Findings

High contrast performance of the vortex coronagraph demonstrated

Comparison with Keck Observatory shows similar limitations

Simulation and real data integration improves testbed modeling

Abstract

The Santa Cruz Extreme AO Lab (SEAL) testbed is an optical bench meant to design and develop new wavefront control techniques for high-contrast imaging for segmented telescopes. These techniques allow for astronomical efficiency in exoplanet imaging and characterization. SEAL consists of several wavefront sensors (WFS) and deformable mirrors (DM) that are currently performing techniques like predictive control or non-linear reconstruction. In this paper, we present the implementation and characterization of a new coronagraphic branch on SEAL and assess the contrast limitations in the testbed. For our coronagraphic branch, we used a vector vortex coronagraph which has high contrast performance. The W. M. Keck Observatory also uses a vortex coronagraph, allowing us to compare the limitations with our own coronagraph. We relied on the testbed and simulations of the vortex coronagraph to compare performance with expected ones. To create a more reliable simulation, we also injected in our numerical model data collected by a Zernike Wavefront sensor (ZWFS) used to perform fine wavefront sensing on the bench. Now that the coronagraphic branch is aligned on SEAL, we will be able to use contrast as a metric for the performance of wavefront control methods on the bench.