A three-dimensional photonic beam combiner for astronomical interferometery

Integrated photonic components have demonstrated outstanding performance in beam combination for infrared astronomical interferometry thanks to their exceptional thermo-mechanical stability and small physical dimensions, suitable for cryogenic assemblies. Planar photonic circuits are currently used in existing devices combining up to 4-telescopes simultaneously on all possible baselines, thus enabling interferometric imaging of fast astronomical events. Addition of a third-dimension in photonic circuits could significantly simplify the design of integrated beam combiners for a large number of telescopes and baselines.