Six-telescope integrated optics beam combiner fabricated using ultrafast laser inscription for J- and H-band astronomy
Aline N. Dinkelaker, Sebastian Smarzyk, Abani S. Nayak, Simone Piacentini, Giacomo Corrielli, Roberto Osellame, Ettore Pedretti, Martin M. Roth, Kalaga Madhav
Published: 2023/6/18
Abstract
We have built and characterized the first six-telescope discrete beam combiner (DBC) for stellar interferometry in the astronomical J-band. It is the DBC with the largest number of beam combinations and was manufactured using ultrafast laser inscription (ULI) in borosilicate glass, with a throughput of approximately 56%. For calibration of the visibility-to-pixel matrix (V2PM), we use a two-input Michelson interferometer and extract the complex visibility. A visibility amplitude of 1.05 and relative precision of 2.9% and 3.8% are extracted for 1328 nm and 1380 nm, respectively. Broadband (< 40 nm) characterization is affected by dispersion, but shows similar performance.