EL HALKOUJ , Thami

The next generation of fringe tracker (FT) is intended to allow continuous fringe observation and to improve significantly the sensitivity of the interferometer. A promising control approach is presented to cope with contradictory requirements. The FT system must be accurate and stable, which implies high frequency sampling of the optical path...

ABSTRACT The spectacular results provided by the second-generationVLTI instruments GRAVITY and MATISSE on active galactic nuclei (AGN) trigger and justify a strong increase in the sensitivity limit of optical interferometers. A key component of such an upgrade is off-axis fringe tracking. To evaluate its potential and limitations, we describe...