Master thesis and internship[BR]- Master's thesis : Development of an advanced modelling tool for a four apertures nulling interferometer[BR]- Integration internship

Abstract

Space-based nulling interferometry for exoplanet detection is a key development area in astrobiology. However, due to the high complexity of its design and the novelty of the required technologies, since Bracewell's first concept in 1978, up to this day it remained only a theoretical mission proposal. In recent years, technological advancements have renewed interest for this technique, leading to new mission proposals that could yield important scientific breakthroughs. In this context, the present work introduces a modelling tool designed to study the behaviour and performance of such instruments, providing a global and preliminary evaluation framework.

Based on models from the literature, the tool offers a flexible analysis of ideal performance metrics, applicable to any number of apertures and geometric configurations: transmission maps, response functions, nulling ratio, modulation efficiency, angular resolution, and point spread functions. A second part of the study focuses on the instrument's sensitivity to internal errors, especially instrumental stellar leakage and optical path differences (OPDs), validating the choice of operating in the mid-infrared range and illustrating the importance of a strong phase control.

Furthermore, the impact of simulated optical aberrations, developed in collaboration with a colleague, is analysed in detail, showing how disturbances affect the signal on the pupil plane and highlighting the limitations of current compensator systems thanks to the integrated response function, where the loss of contrast of the perturbed simulations is particularly evident.

Finally, the tool is applied to three mission concepts—ESA’s Darwin, NASA’s TPF-I, and ETH’s LIFE—offering a comparative performance analysis (in terms of resolution, nulling ratios, modulation efficiency and exoplanet yield) and further demonstrating the scientific potential of space-based nulling interferometry.