Integrated discrete beam combiner with a pupil remapper for stellar interferometry (Conference Presentation)

Stellar interferometry performed in integrated photonic devices allows to increase the angular resolution of a ground-based telescope. Here we present the fabrication and characterization of a low-loss polarization insensitive photonic circuit for astrophotonics, whose geometry was engineered to combine interferometrically up to eight input beams. The employed fabrication technique consisted in the femtosecond laser micromachining followed by a thermal annealing to reduce the birefringence of the waveguides. The fabricated device was characterized to validate its functioning in terms of polarization insensitivity, good transmission and proper beam combination, thus benchmarking its suitability with real on-sky observations.