Integrated photonic-based coronagraphic systems for future space telescopes

TL;DR

This paper reviews photonic coronagraphs and explores hybrid designs combining classical and photonic technologies to improve high-contrast imaging of Earth-like exoplanets for future space telescopes.

Contribution

It introduces two innovative hybrid photonic coronagraph configurations that enhance starlight suppression and relax system requirements.

Findings

Hybrid designs can improve inner working angle performance.

Series operation of systems relaxes subsystem constraints.

Photonic technologies could significantly increase exo-Earth detection yield.

Abstract

The detection and characterization of Earth-like exoplanets around Sun-like stars is a primary science motivation for the Habitable Worlds Observatory. However, the current best technology is not yet advanced enough to reach the 10^-10 contrasts at close angular separations and at the same time remain insensitive to low-order aberrations, as would be required to achieve high-contrast imaging of exo-Earths. Photonic technologies could fill this gap, potentially doubling exo-Earth yield. We review current work on photonic coronagraphs and investigate the potential of hybridized designs which combine both classical coronagraph designs and photonic technologies into a single optical system. We present two possible systems. First, a hybrid solution which splits the field of view spatially such that the photonics handle light within the inner working angle and a conventional coronagraph that suppresses starlight outside it. Second, a hybrid solution where the conventional coronagraph and photonics operate in series, complementing each other and thereby loosening requirements on each subsystem. As photonic technologies continue to advance, a hybrid or fully photonic coronagraph holds great potential for future exoplanet imaging from space.