Dirk worked on the implementation of modern control techniques for local control, i.e to damp the fundamental eigenmodes of triple suspensions, which are used to suppress the seismic noise coupling into the interferometer. For the realisation of this control approach complete knowledge of the system dynamics is required and therefore the motion of the lower suspension stage is read out by an optical lever. With the obtained knowledge it is possible to set up a state space model, which will then be used to compute a suitable modern controller. In this case it will consist of a linear quadratic regulator and a time-invariant Kalman filter.
Additionally, Dirk worked on a modern controller to lock the cavity of a sub-threshold optical parametric oscillator and its corresponding pump phase to guarantee a stable squeezed output.
In July 2017 Dirk joined the workforce in industry 🙂
- D. Schütte, S. Z. Sayed Hassen, Kai Karvinen, Toby K. Boyson, Abhijit G. Kallapur, Hongbin Song, Ian R. Petersen, Elanor H. Huntington, and Michèle Heurs: Experimental demonstration of frequency auto-locking an optical cavity using a time-varying Kalman filter, Physical Review Applied 5, 014005 (2016)
- D. Schütte: Modern Control Approaches for Next-Generation Interferometric Gravitational Wave Detectors, PhD thesis, Leibniz Universität Hannover (2016)