Extending the Astrophysical Reach of Gravitational-Wave Detectors through New Adaptive Optical Technology

We present a new adaptive optical technology called FROSTI with the potential to expand the detection horizon of the current gravitational-wave observatories such as LIGO. FROSTI provides high-precision, low-noise wavefront actuation on the core interferometer optics to mitigate the limiting impact of thermal distortions due to coating absorption, beyond current thermal compensation capabilities. It can enable significantly higher levels of laser power buildup and improved quantum squeezing performance in gravitational-wave detectors, resulting in a greater quantum-noise-limited sensitivity. In simulated projections for achieving and exceeding the LIGO A+ design sensitivity, we find that this technology can reduce the quantum-limited noise floor of the LIGO detectors by up to an additional 22%, resulting in a significant expansion of the observable volume of universe and a commensurate increase in astrophysical event rates. This work lays the foundation for one of the key technology improvements essential to fully utilize the scientific potential of the existing 4-km LIGO facilities, to observe black hole merger events past a redshift of 5, and opens a realistic pathway towards a next-generation 40-km gravitational-wave observatory in the United States, Cosmic Explorer.