Observations at mas-resolution scales and high dynamic range hold a central place in achieving, for instance, the spectroscopic characterization of exo-Earths or the detailed mapping of their protoplanetary disc birthplace. Ground or space-based multi-aperture infrared interferometry is a promising technique to tackle these goals. But significant efforts still need to be undertaken to achieve a simplification of these instruments if we want to combine the light from a large number of telescopes. Integrated-optics appears as an alternative to the current conventional designs, especially if its use can be extended to a higher number of astronomical bands. This article reports for the first time the experimental demonstration of the feasibility of an integrated-optics approach to mid-infrared beam combination for single-mode stellar interferometry. We have fabricated a 2-telescope beam combiner prototype integrated on a substrate of chalcogenide glasses, a material transparent from 1 to 14 um. We have developed laboratory tools to characterize the modal properties and the interferometric capabilities of our device. We obtain fringes at 10 um and measure a mean contrast V=0.981 \pm 0.001 with high repeatability over one week and high stability over 5h. We show experimentally - as well as on the basis of modeling considerations - that the component has a single-mode behavior at this wavelength, which is essential to achieve high-accuracy interferometry. From previous studies, the propagation losses are estimated to 0.5 dB/cm for such components. We also discuss possible issues that may impact the interferometric contrast. The IO beam combiner performs well at 10. We also anticipate the requirement of a better matching between the numerical apertures of the component and the (de)coupling optics to optimize the total throughput. The next step foreseen is the achievement of wide-band interferograms.
Stellar interferometry with a K-band integrated optics beam combiner instrument at the CHARA Array - I. First on-sky fringes for CHARIOT
Corning Optical Communications GmbH & Co. KG（康宁光学通讯有限公司）；Leibniz-Institut für Astrophysik Potsdam（波茨坦阿斯特罗物理学会莱布尼茨研究所）；I. Physikalisches Institut, Universität zu Köln（科隆大学第一物理研究所）；The CHARA Array of Georgia State University（佐治亚州立大学CHARA阵列）；Institute of Photonics and Quantum Sciences, Heriot-Watt University（赫瑞-瓦特大学光子与量子科学研究所）；Humboldt-Universität zu Berlin（柏林洪堡大学）
Large Interferometer For Exoplanets (LIFE): VII. Practical implementation of a five-telescope kernel-nulling beam combiner with a discussion on instrumental uncertainties and redundancy benefits
On-sky demonstration of dual-field interferometry at the CHARA Array
The CHARA Array of Georgia State University Mount Wilson Observatory Mount Wilson California USA（佐治亚州立大学查拉阵列威尔逊山天文台）；Department of Astronomy University of Michigan Ann Arbor Michigan USA（密歇根大学天文学系）；School of Physics and Astronomy University of Exeter Exeter United Kingdom（埃克塞特大学物理与天文学院）；Université Côte d’Azur Observatoire de la Côte d’Azur CNRS Laboratoire Lagrange Nice France（蔚蓝海岸大学蔚蓝海岸天文台法国国家科学研究中心拉格朗日实验室）
Pushing high angular resolution and high contrast observations on the VLTI from Y to L band with the Asgard instrumental suite: integration status and plans
Technologies and novel components for broadband splitting and coupling in pairwise and nulling interferometry
Astrophotonics Australia, Monash（蒙纳士大学天体光子学澳大利亚）；Department of Astronomy, California Institute of Technology（加州理工学院天文系）；Physics & Astronomy Department, University of California, Los Angeles（加州大学洛杉矶分校物理与天文系）；LIRA, Observatoire de Paris, Université PSL, CNRS, Sorbonne Université, Université de Paris（巴黎天文台LIRA实验室，巴黎文理研究大学，法国国家科学研究中心，索邦大学，巴黎大学）；Commissariat à l’Energie Atomique, Leti（法国原子能和替代能源委员会LETI实验室）；Astralis-AITC, Research School of Astronomy and Astrophysics, Australian National University（澳大利亚国立大学天文与天体物理研究学院）；Department of Quantum Science, Research School of Physics, Australian National University（澳大利亚国立大学量子科学系，物理研究学院）
NAIR-APREXIS: Enabling photonics-based instruments for long-baseline interferometry and integral-field spectroscopy
I. Physikalisches Institut, Universität zu Köln（科隆大学第一物理研究所）；Centre for Advanced Instrumentation, Department of Physics, Durham University（杜伦大学物理系先进仪器中心）；Leibniz-Institut für Astrophysik Potsdam（波茨坦莱布尼茨天体物理研究所）；Institute of Photonics and Quantum Sciences, Heriot-Watt Univ.（赫瑞-瓦特大学光子与量子科学研究所）；The CHARA Array of Georgia State University, Mount Wilson Observatory（佐治亚州立大学CHARA阵列威尔逊山天文台）；Corning Optical Communications GmbH & Co. KG（康宁光学通信有限公司）
Pushing high angular resolution and high contrast observations on the VLTI from Y to L band with the Asgard instrumental suite: integration status and plans
Université Côte d’Azur, Observatoire de la Côte d’Azur, CNRS, Laboratoire Lagrange（蔚蓝海岸大学、蔚蓝海岸天文台、法国国家科学研究中心、拉格朗日实验室）；Research School of Astronomy and Astrophysics, College of Science, Australian National University（澳大利亚国立大学理学院天文学与天体物理学家研究学院）；School of Physics and Astronomy, University of Exeter（埃克塞特大学物理与天文学院）；Institute of Astronomy, KU Leuven（鲁汶大学天文学研究所）；Space sciences, Technologies & Astrophysics Research (STAR) Institute, University of Liège（列日大学空间科学与技术天体物理研究（STAR）研究所）；Institute for Particle Physics and Astrophysics, ETH Zurich（苏黎世联邦理工学院粒子物理与天体物理研究所）；Department of Astronomy and Steward Observatory（天文学系及斯图尔德天文台）；Large Binocular Telescope Observatory（大型双筒望远镜天文台）；I. Physikalisches Institut, Universität zu Köln（科隆大学第一物理研究所）；European Organisation for Astronomical Research in the Southern Hemisphere（欧洲南方天文台）；Max-Planck-Institut für Astronomie（马克斯·普朗克天文学研究所）；Konkoly Observatory（孔科利天文台）；University of California, Los Angeles（加州大学洛杉矶分校）；Leiden Observatory, Leiden University（莱顿大学莱顿天文台）；Australian Astronomical Optics & School of Mathematical and Physical Sciences, Macquarie University（麦考瑞大学澳大利亚天文光学部及数学与物理科学学院）；Research Software Engineering, NUIT, Newcastle University（纽卡斯尔大学NUIT研究软件工程）
