High contrast imaging at the photon noise limit with self-calibrating WFS/C systems

TL;DR

This paper proposes a novel approach combining multiple high-efficiency wavefront sensors across spectral ranges to calibrate residual starlight at the photon noise limit, demonstrated through laboratory and on-sky experiments.

Contribution

It introduces a self-calibrating wavefront sensing system that enhances residual starlight calibration by leveraging combined telemetry from multiple sensors.

Findings

Effective residual starlight calibration achieved in laboratory experiments.

On-sky demonstration confirms the method's practical viability.

Improved wavefront sensing sensitivity through multi-sensor data fusion.

Abstract

High contrast imaging (HCI) systems rely on active wavefront control (WFC) to deliver deep raw contrast in the focal plane, and on calibration techniques to further enhance contrast by identifying planet light within the residual speckle halo. Both functions can be combined in an HCI system and we discuss a path toward designing HCI systems capable of calibrating residual starlight at the fundamental contrast limit imposed by photon noise. We highlight the value of deploying multiple high-efficiency wavefront sensors (WFSs) covering a wide spectral range and spanning multiple optical locations. We show how their combined information can be leveraged to simultaneously improve WFS sensitivity and residual starlight calibration, ideally making it impossible for an image plane speckle to hide from WFS telemetry. We demonstrate residual starlight calibration in the laboratory and on-sky, using both a coronagraphic setup, and a nulling spectro-interferometer. In both case, we show that bright starlight can calibrate residual starlight.