Dr. Guido Mueller
Prof. Dr. Guido Mueller,
Department of Physics, University of Florida
Research
LISA
Interferometry Measurement System
• My group developed the only interferometer testbed which allows to test LISA
interferometry in the relevant environment including Doppler shifts and
changing LISA-like light travel times. We tested time delay interferometry (TDI)
and ranging techniques. Our TDI experiments were the first to demonstrate the
cancellation of laser frequency noise in the TDI signals and showed how the
signals can be used to find the range or signal travel time between lasers.
• We measured the fidelity of components for the laser ranging and
communication system for the LISA interferometry. We also measured the
fidelity of multiple components used in the ranging and communication system
and continue to study their impact on TDI.
• We studied frequency stabilization methods including different versions of arm
locking and integrated them with different pre-stabilization methods. We
discovered issues with the Doppler estimation which could have endangered
the entire mission and we studied the influence of various noise sources on the
performance of arm locking.
Materials and structures for LISA
• We measured the stability of several important materials to study if they meet
the stringent requirements for LISA. We also developed a strong, ultra-stable
bonding method for silicon and oxygen containing materials useful for optical
benches and telescope structures. Lately, we started to study the mechanical
stability and methods to reduce the back-scatter in an on-axis telescopes for
LISA.
Gravitational Reference Sensor
• We started to assemble a testbed for the Gravitational Reference Sensor for
future LISA-like space missions. The testbed will use a four testmass torsion
pendulum similar to the testbed of the University of Trento.
Advanced LIGO
• I developed one of the initial length sensing and control schemes and the first
alignment sensing and control scheme for Advanced LIGO.
• I also derived requirements for the laser beam pointing into the Advanced LIGO
interferometer and track the requirements between the laser, the input optics,
and the main interferometer for the IO.
• We studied a new optical layout for Advanced LIGO which stabilizes the spatial
mode of the laser field within the recycling cavities. This new design has been
implemented for Advanced LIGO and our group has developed the final design
Dr. Guido Mueller
for Advanced LIGO.
• We are now developing a new ring heater for Advanced LIGO and started
experimental and numerical tests for the thermal correction system for
Advanced LIGO
• We started a new experiment to measure coating thermal noise within the
Advanced LIGO band directly to support the development and characterization
of coatings with less thermal noise.
International REU for Gravitation
• Developed a program which currently sends on average 15 US undergraduate
students each year to our international partners in Europe, Australia, and Asia.
Several of these students are still working on gravitational wave detection in the
US (including UF) or at our partner institutions abroad.
Other currently unfunded research activities
• Design and planning of 'shining light through walls' experiment for Axion and
other dark matter searches