Imaging power of multi-fibered nulling telescopes for extra-solar planet characterization

TL;DR

This paper evaluates the imaging capabilities of multi-fibered nulling telescopes, comparing different designs for detecting habitable exoplanets, and provides theoretical and simulation-based insights into their performance metrics.

Contribution

It introduces and compares three nulling telescope concepts, providing theoretical models and simulations to assess their effectiveness for exoplanet imaging.

Findings

High radiometric efficiency SRTs are promising with proper calibration.

Masked SPTs can achieve deeper nulling but may have lower SNR.

Design choice depends on desired nulling depth versus signal quality.

Abstract

In this paper are discussed the nulling and imaging properties of monolithic pupil telescopes equipped with a focal plane waveguide array, which could be envisaged as precursor space missions for future nulling interferometers or coronagraphs searching for habitable planets outside of our solar system. Three different concepts of nulling telescopes are reviewed, namely the Super-Resolving Telescope (SRT) having multiple, non-overlapping exit sub-apertures and the Sheared-Pupil Telescope (SPT), either unmasked or masked with a Lyot stop placed at its exit pupil plane. For each case simple theoretical relationships allowing to estimate the nulling rate, Signal-to-Noise Ratio (SNR) and Inner Working Angle (IWA) of the telescope are established or recalled, and numerical simulations are conducted. The preliminary results of this study show that the most promising designs should either be a SRT of high radiometric efficiency associated with an adequate leakage calibration procedure, or a masked SPT with potentially deeper nulling rates but lower SNR, depending on what kind of performance is to be preferred.