Testing of Portable Compact Optomechanical Seismic Sensors for LIGO

About This Grant

This award supports the advancement of compact optomechanical sensing technologies designed to deliver highly sensitive measurements of seismic phenomena. Seismic activity and slow vibrations limit the efficacy of suspensions designed to provide ultra-stable experimental platforms for precision metrology and improved sensing capabilities. This project will advance the technology of optomechanical seismic sensors, enabling the team to assess their performance under laboratory conditions. In parallel, novel readout schemes will be explored to enhance sensitivity. Characterizing the sensor’s sensitivity, bandwidth, and functionality on a suspended, in-vacuum platform will help predict its performance in future gravitational wave observatories such as NSF's Laser Interferometer Gravitational-Wave Observatory (LIGO) and Cosmic Explorer, which is the primary application of this research. However, the devices will also benefit other scientific and industrial fields where compact, high-sensitivity instruments are valuable. These include seismology, geodesy, precision vibration measurements, inertial sensing, and inertial navigation. In addition, this award will support the group’s involvement in the international LIGO Scientific Collaboration and the broader gravitational wave community, while fostering STEM training for students and promoting public education on gravitational wave science. This project targets the development of compact and highly sensitive optomechanical seismic sensors for LIGO. Seismic noise poses a major challenge for gravitational wave (GW) detectors like LIGO, particularly at low frequencies where it obscures astrophysical signals and couples non-linearly into the detector response. While existing commercial seismometers offer reasonable performance, their size, complexity, and incompatibility with vacuum environments make them non-ideal for the extreme conditions expected in next-generation observatories such as LIGO Voyager and Cosmic Explorer. This project addresses that limitation by advancing the development of compact, vacuum-compatible optomechanical seismic sensors with target sensitivities on the order of 10−10 m/s2/Hz-1/2 from 10 mHz to tens of Hz. The aim is to finalize a portable prototype and conduct huddle testing under LIGO-like conditions. The effort includes optimizing the mechanical resonator design and investigating high-finesse optical cavities and spatial-mode interference schemes as novel displacement readout techniques. In addition to advancing low-frequency seismic isolation for GW observatories, the project will engage students in international project work through the LIGO Scientific Collaboration and offers training in optomechanics, electronics, and laser interferometry. Advancing novel technologies to levels where they become portable and can be deployed, offers a wide variety of relevant interdisciplinary aspects within STEM areas for the training of future experimental physicists and engineering professionals. Broader impacts include potential applications in metrology, inertial navigation, and planetary exploration, where high-sensitivity compact sensors are increasingly critical. 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.