In September 2015 the two Advanced LIGO observatories reached their initial goal: the detection of gravitational waves. Advanced LIGO, designed for a 10x sensitivity improvement and much better low-frequency response, now has seen inspiraling binary black holes at least three times. The improved sensitivity came from higher laser power, better isolation from ground motion, and changes to the interferometers themselves. The higher laser power presented challenges for the input optics, a responsibility of the University of Florida. This research will address improvements in performance of the input optics and of controls for the interferometer as a whole. It also addresses the next generation of detectors to increaser further the LIGO science reach, enabling better observations of gravitational waves from black holes, neutron stars and other massive astrophysical events. The research has impacts that go beyond gravitational wave science as high-power optical devices developed in this project have commercial applications to the laser and optics industries. In addition, the students and postdoctoral scientists develop scientific skills from a diverse set of disciplines spanning lasers and optics, electronics and feedback control systems, vacuum and cryogenics, and large-scale detector commissioning and operation.
In support of near-term and longer-range gravitational-wave research, the UF LIGO group will carry out a number of research projects that impact instrument science for future gravitational-wave. A method for generating arbitrary modulation sidebands will be developed. Work on low-loss Faraday isolators (key components of the squeezer that is planned in the near future) will be completed. Application of modern estimation and control techniques to LIGO suspension systems will be investigated. A novel scheme for alignment sensing as well as a novel position-sensitive laser beam detector will be studied. Looking further into the future, experiments to measure impurities and free carrier absorption in various types of high purity silicon suitable for cryogenically cooled test masses will be conducted.