Advanced Laser-writing for Stellar Interferometry – ALSI

Funding agency: BMBF

Partners: University of Jena, University of Cologne, Max Plank Institute for Astronomy Heidelberg

Funding period: 2014-2017


With the ALSI project, we propose to focus on mastering the technology of laser-written

photonics in infrared glasses transparent in the 1-10 μm spectral range to develop near- and

mid-infrared integrated-optics beam combiners for future fringe-tracking systems for stellar

interferometry. The final goal of our proposal is to demonstrate the manufacturing of

sophisticated integrated optics beam combiners, which optimally respond to the specific

requirements and challenges of stellar interferometry (e.g. control of the phase errors, strong

immunity to vibrations, sensitivity in low-flux conditions). The outcome of this work will have

direct applications for fringe-tracking subsystems operating at longer infrared wavelengths

(2.2 to 3.6 microns) than today, which in the current infrastructure and science context of the

VLTI will contribute to broaden the science return of the facility.


A highlight of the preliminary results of the project is found [here]

The ALSI page at the university of Cologne is found [here].


ALSI will investigate and compare thevarious existing strategies for interferometric beam-combination with integrated optics in infrared transparent materials (2-4 microns).