Dr. Sina Maria Köhlenbeck
Postdoc in the Laser Interferometry and Gravitational Wave Astronomy department, coordinator of the Max-Planck-Fraunhofer project “High-QG”
What is your current position at our institute?
I am a Postdoc at the Max Planck Institute for Gravitational Physics in Hanover and I also coordinate the cooperative project “High-QG” between the Max Planck Society and the Fraunhofer-Gesellschaft.
What is your academic education?
- ERASMUS at the University of Copenhagen (2008/2009)
- Diploma from the University of Hannover (2012)
- PhD at the Max Planck Institute for Gravitational Physics
What were your previous academic positions?
- Post-Doc at the Max Planck Institute for Gravitational Physics (10m interferometer prototype)
- Post-Doc at the Max Planck Institute for Gravitational Physics (High-QG)
Please describe your research in general terms.
My research focuses on the experimental side of gravitational-wave detection and helps to improve the operation and sensitivity of gravitational wave detectors. I am the coordinator of a project named High-QG, which addresses two main challenges in gravitational-wave detectors. The first is Brownian thermal noise of the mirror coatings in the laser interferometer at the heart of the detector. The Brownian motion of the mirror surface masks the effect of gravitational waves as they pass the detector. With resonant waveguide mirrors this noise source can potentially be reduced. One part of the project is therefore to measure the thermal noise characteristics of this type of mirrors. The other part is the development of inertial sensors to measure the ground motion shaking and thereby disturbing earth-based gravitational-wave detectors. Commercial sensors can no longer meet the requirement for the next generation of gravitational-wave detectors. We develop a sensor that uses interferometric readout of an all-glass oscillator to reduce the mass significantly and allow operation in high vacuum environments. Apart from the coordination of the project, my contributions include the development and testing of ultra-stable fiber injectors and frequency references.
Do you have a favorite figure from a paper you (co-)authored?
The figure is from a paper that included work from my diploma thesis. It shows a measurement of the resolvable multi-round trips of light bouncing between two partially reflecting mirrors. Each reflection is forming an interferometer with a reference beam (not shown). The technique under investigation allows one to measure all these interferometers simultaneously, whereas conventional interferometry could not distinguish between them and would measure the accumulated phase change of them together. Highspeed multiplexed heterodyne interferometry therefore also allows for more compact settings and the mitigation of stray light, which is a common problem in interferometry.
Please let us know why you chose the Max Planck Institute for Gravitational Physics for your research.
The director Prof. Dr. Karsten Danzmann lectured the first-year course for experimental physics, and him being a great teacher and telling us about the research at his institute, made me very curious already. When I was looking for a diploma project, I visited several institutes and the project at the Max Planck Institute for Gravitational Physics was simply the most interesting one.