Asgard/NOTT: Status of laboratory nulling performance
Abstract
Nulling interferometry enables the direct detection of faint companions and circumstellar structures at angular separations unresolvable by classical, diffraction-limited imagers, whilst dramatically improving the measurable contrast. The Asgard/NOTT nulling instrument aims to achieve a contrast performance of 10^-5 in the L' wavelength band (3.5 - 4.0 μm), enabling observation and characterization of young giant exoplanets near the snowline and hot exozodiacal dust. Previous studies have verified the nulling capabilities, of the chip in ambient conditions and of the test bench in cryogenic conditions. This work aims to add the first ambient performance assessment of the test bench with spectrally dispersed light. Necessary revisions are made to the data acquisition and calibration pipeline and fringe scans are carried out, modeled and fitted. The splitting ratios of the 4-telescope nulling beam combiner, a photonic Gallium Lanthanum Sulfide (GLS) chip, are moreover characterized on the bench, showing tentative agreement with previous chip characterization. The null performance has worsened, the achieved contrast of ~ 10^-1 being one order of magnitude higher than what earlier characterized performance showed. Multiple future changes to the test bed and to the approach taken promise an improved characterization of performance. In particular, the input beam intensities will be deliberately mismatched to account for the imbalanced splitting ratios of the directional couplers. With the installation of the final cryostat and camera, the developed tools will be leveraged to re-assess the performance in ambient and cryogenic conditions.
Versions
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BibTeX
@misc{mattheussen2026asgardnott,
title = {{Asgard/NOTT: Status of laboratory nulling performance}},
author = {T. Mattheussen and R. Laugier and D. Defrère and G. Garreau and P. Chingaipe and G. Raskin and M. Salman and K. Missiaen and B. Vandenbussche and W. Verstraeten and J. Morren and A. Kuriakose and M. Ireland and M. -A. Martinod and A. Sanny and S. Gross and L. Labadie and A. Bigioli and A. Jóo and S. Madden and A. Mazzoli and G. Medgyesi and S. Ertel and T. A. Stuber and J. P. Scott and S. Kraus and F. Martinache and X. Haubois and N. Schuhler},
howpublished = {arXiv},
year = {2026},
month = aug,
doi = {10.48550/arxiv.2608.18951},
eprint = {2608.18951},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2608.18951},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - Asgard/NOTT: Status of laboratory nulling performance
AU - T. Mattheussen
AU - R. Laugier
AU - D. Defrère
AU - G. Garreau
AU - P. Chingaipe
AU - G. Raskin
AU - M. Salman
AU - K. Missiaen
AU - B. Vandenbussche
AU - W. Verstraeten
AU - J. Morren
AU - A. Kuriakose
AU - M. Ireland
AU - M. -A. Martinod
AU - A. Sanny
AU - S. Gross
AU - L. Labadie
AU - A. Bigioli
AU - A. Jóo
AU - S. Madden
AU - A. Mazzoli
AU - G. Medgyesi
AU - S. Ertel
AU - T. A. Stuber
AU - J. P. Scott
AU - S. Kraus
AU - F. Martinache
AU - X. Haubois
AU - N. Schuhler
PY - 2026
DA - 2026/08/19
PB - arXiv
DO - 10.48550/arxiv.2608.18951
UR - https://arxiv.org/abs/2608.18951
AB - Nulling interferometry enables the direct detection of faint companions and circumstellar structures at angular separations unresolvable by classical, diffraction-limited imagers, whilst dramatically improving the measurable contrast. The Asgard/NOTT nulling instrument aims to achieve a contrast performance of 10^-5 in the L' wavelength band (3.5 - 4.0 μm), enabling observation and characterization of young giant exoplanets near the snowline and hot exozodiacal dust. Previous studies have verified the nulling capabilities, of the chip in ambient conditions and of the test bench in cryogenic conditions. This work aims to add the first ambient performance assessment of the test bench with spectrally dispersed light. Necessary revisions are made to the data acquisition and calibration pipeline and fringe scans are carried out, modeled and fitted. The splitting ratios of the 4-telescope nulling beam combiner, a photonic Gallium Lanthanum Sulfide (GLS) chip, are moreover characterized on the bench, showing tentative agreement with previous chip characterization. The null performance has worsened, the achieved contrast of ~ 10^-1 being one order of magnitude higher than what earlier characterized performance showed. Multiple future changes to the test bed and to the approach taken promise an improved characterization of performance. In particular, the input beam intensities will be deliberately mismatched to account for the imbalanced splitting ratios of the directional couplers. With the installation of the final cryostat and camera, the developed tools will be leveraged to re-assess the performance in ambient and cryogenic conditions.
ER -