Simulation and development of astrophotonic H-band nulling beam combiner for the CHARA Array
Abstract
Nulling interferometry is a promising method for direct detection and characterization of faint stellar companions such as exoplanets and faint binary sources. The dominant constraint on instrument performance is instability noise from vibrations, thermal expansions, and other systematic sources. Photonic instruments have footprints of a few centimeters and enable advanced light control architectures. Astrophotonic implementations can include active phase control via Mach-Zehnder interferometers (MZIs) to actively minimize residual optical path errors at the location of beam combination. The compact size of photonic chips also makes them a promising solution for space-based applications such as the upcoming Habitable Worlds Observatory. The Center for High Angular Resolution Astronomy (CHARA) Array is equipped with the world's longest baseline in the near-infrared at 330 meters long. CHARA therefore has the most sensitive angular resolution in the near-infrared. A nuller at CHARA would have access to a novel parameter space essential for exoplanet discovery and characterization. The first step in preparing a nulling beam combiner for CHARA is to develop compelling, realistic, and well-defined science cases. Simulation suites quantify the technical requirements to reach such science goals in their respective complex systems. The CHARA Array Response Model (CHARM) is the first-ever simulator built specifically for CHARA, opening up new pathways for instrument simulation. CHARM is a flexible simulation tool of an H-band, self-calibrated astrophotonic nulling beam combiner with active phase control for the CHARA Array. In this paper, we present an update on the development of our photonic nulling beam combiner for CHARA. We include early results from CHARM, demonstrating that the photonic nuller has the potential to detect and characterize a wide range of bright stellar companion systems.
Related
- Stellar interferometry with a K-band integrated optics beam combiner instrument at the CHARA Array - I. First on-sky fringes for CHARIOT
- CHARA/SPICA: The six-telescope visible combiner and near-infrared fringe tracker for the CHARA Array
- Qualification pathways for Photonic Integrated Circuits in Astrophotonic Space Missions
- Inverse-designed tapers to improve throughput of on-chip astrophotonic spectrographs
- Investigating the subpulse drifting and periodic nulling behavior of the long-period pulsar PSR J1831-1223 with FAST
BibTeX
@misc{morrison2026simulation,
title = {{Simulation and development of astrophotonic H-band nulling beam combiner for the CHARA Array}},
author = {Samantha G. Morrison and Pradip Gatkine and Michael P. Fitzgerald},
howpublished = {arXiv},
year = {2026},
month = sep,
doi = {10.48550/arxiv.2609.00260},
eprint = {2609.00260},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2609.00260},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - Simulation and development of astrophotonic H-band nulling beam combiner for the CHARA Array
AU - Samantha G. Morrison
AU - Pradip Gatkine
AU - Michael P. Fitzgerald
PY - 2026
DA - 2026/09/01
PB - arXiv
DO - 10.48550/arxiv.2609.00260
UR - https://arxiv.org/abs/2609.00260
AB - Nulling interferometry is a promising method for direct detection and characterization of faint stellar companions such as exoplanets and faint binary sources. The dominant constraint on instrument performance is instability noise from vibrations, thermal expansions, and other systematic sources. Photonic instruments have footprints of a few centimeters and enable advanced light control architectures. Astrophotonic implementations can include active phase control via Mach-Zehnder interferometers (MZIs) to actively minimize residual optical path errors at the location of beam combination. The compact size of photonic chips also makes them a promising solution for space-based applications such as the upcoming Habitable Worlds Observatory. The Center for High Angular Resolution Astronomy (CHARA) Array is equipped with the world's longest baseline in the near-infrared at 330 meters long. CHARA therefore has the most sensitive angular resolution in the near-infrared. A nuller at CHARA would have access to a novel parameter space essential for exoplanet discovery and characterization. The first step in preparing a nulling beam combiner for CHARA is to develop compelling, realistic, and well-defined science cases. Simulation suites quantify the technical requirements to reach such science goals in their respective complex systems. The CHARA Array Response Model (CHARM) is the first-ever simulator built specifically for CHARA, opening up new pathways for instrument simulation. CHARM is a flexible simulation tool of an H-band, self-calibrated astrophotonic nulling beam combiner with active phase control for the CHARA Array. In this paper, we present an update on the development of our photonic nulling beam combiner for CHARA. We include early results from CHARM, demonstrating that the photonic nuller has the potential to detect and characterize a wide range of bright stellar companion systems.
ER -