Photonics-based mid-infrared interferometry: 4-year results of the ALSI project and future prospects
L. Labadie, S. Minardi, J. Tepper, R. Diener, B. Muthusubramanian, J.-U. Pott, S. Nolte, S. Gross, A. Arriola, M. J. Withford
Proceedings Volume 10701, Optical and Infrared Interferometry and Imaging VI; 107011R (2018) https://doi.org/10.1117/12.2312930
In this contribution, we review the results of the ALSI project (Advanced Laser-writing for Stellar Interferometry), aimed at assessing the potential of ultrafast laser writing to fabricate mid-infared integrated optics (IO) devices with performance compatible with an implementation in real interferometric instruments like Hi5 or PFI. Waveguides for the L, L' and M bands with moderate propagation losses were manufactured in Gallium Lanthanum Sulfide and ZBLAN glasses and used to develop photonic building blocks as well as a full mid-IR 4-telescope beam combiner. We discuss the advantages and disadvantages of the tested combiners and discuss a possible roadmap for the continuation of this work.