Integrated optics for astronomical interferometry - VI. Coupling the light of the VLTI in K band

摘要: Aims. Our objective is to prove that integrated optics (IO) not o nly a good concept for astronomical interferometry but also working technique with high performance. Methods. We used the commissioning data obtained dedicated K-band two-telescope beam combiner which now replaces fiber coupler MONA in VLTI/VINCI instrument. characterize behaviour of this IO device and compare its properties other single mode like previously coupler. Results. The provides optical throughput, contrast 89% night-to-night stability few percent. Even if dispersive phase present, we show it does bias measured Fourier visibility estimate. An upper limit 5× 10 −3 cross-talk between linear polarization states has been measured. take advantage intrinsic test ne w prodecure calibrating diameters simple stars by simultaneousl y fitting instrumental apparent stellar diameters. This method reaches an accuracy diameter errors order previous ones without need already known calibrator. Conclusions. These results are important step optics, si nce they maturity band where technology specially developed conveniences. It paves road incoming imaging interferometer projects.