This award supports research in gravitational wave detector instrumentation and it addresses the priority areas of NSF's "Windows on the Universe" Big Idea. This award sponsors the development of novel compact seismic sensing technologies that provide highly sensitive observations of slow seismic phenomena on platforms under extreme conditions such as low pressures (vacuum) and low temperatures (cryogenics). In this project, parameters of sensitivity and bandwidth will be studied to develop optomechanical seismic sensors that are compatible with and can be installed in future gravitational wave observatories, such as LIGO Voyager. Seismic sensors are used to measure external disturbances acting on the platforms and provide signals than can be used to stabilize them. Moreover, the research conducted in this project will advance the development of technologies that enable further advancements relevant to other scientific and technological areas such as seismology, geodesy, precision measurements of vibrations, generally inertial sensing and inertial navigation, where highly compact form factors and high sensitivities can be advantageous. This award will support the participation of this research group in activities of the international LIGO Scientific Collaboration and the gravitational wave community at large; also providing for students to be trained in precision measurements and STEM areas, and helping to educate the local community in the new area of gravitational wave astronomy. This project aims to develop highly compact monolithic optomechanical seismic sensors for ground-based gravitational wave observatories, such as LIGO, as an alternative to current solutions. LIGO currently uses commercial seismometers that are not readily compatible with vacuum or low temperature environments and are physically large - approximately 15 kg and 30 liters. Inertial sensors capable of operating in these conditions are required for future gravitational wave detectors, such as LIGO Voyager, and need to be developed, which is the goal of this project. In addition, the research plan envisions the development of an optomechanical seismic sensing instrument that will serve as a test platform to assess relevant sensor parameters to guide the technology development and help study their performance at low frequencies - from 10 mHz to slightly above 10 Hz. These results will outline the path for the development of cryogenic- and vacuum-compatible optomechanical seismic sensors for future generation gravitational wave observatories and will be relevant to many other STEM areas. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
