Asgard/NOTT: First lab assembly and experimental results

TL;DR

Asgard/NOTT is a novel instrument designed for high-contrast imaging of exoplanets and dust around stars, with first lab assembly and experimental results demonstrating its capabilities for nulling in the mid-infrared.

Contribution

This work presents the first lab assembly and experimental validation of the Asgard/NOTT instrument, including its opto-mechanical design and nulling performance in the mid-infrared.

Findings

Successful lab assembly of the instrument.

Demonstration of fringes and null measurements.

Validation of the bench for future on-sky testing.

Abstract

Asgard/NOTT is an ERC-funded project hosted at KU Leuven and is part of a new visitor instrumental suite, called Asgard, under preparation for the Very Large Telescope Interferometer (VLTI). Leveraging nulling capabilities and the long VLTI baselines, it is optimized for high-contrast imaging of the snow line region around young nearby main-sequence stars. This will enable the characterization of the atmosphere of young giant exoplanets and warm/hot exozodiacal dust with spectroscopy in the L'-band (3.5-4.0$\mu$m). In this work, we present the first lab assembly of the instrument done at KU Leuven and the technical solutions to tackle the challenge of performing nulling in the mid-infrared despite the thermal background. The opto-mechanical design of the warm optics and the injection system for the photonic chip are described. The alignment procedure used to assemble the system is also presented. Finally, the first experimental results, including fringes and null measurements, are given and confirm the adequacy of the bench to test and optimize the Asgard/NOTT instrument.