Collaborative Research: Center for Coatings Research

The Center for Coatings Research (CCR) focuses on the development of advanced mirror coatings for gravitational wave detectors, a new and booming field of observational astrophysics. By reducing mechanical loss and thus thermal noise in mirror coatings, the project aims to enhance the sensitivity of Cosmic Explorer (CE), the proposed third generation gravitational wave detector. This research holds significant importance as it expands our understanding of the universe by enabling observations of cosmic events, such as the collision of remnants from the first stars. Moreover, the project has broader impacts on precision measurement technology, benefiting areas like precision timing, quantum information, low noise interferometry, and the search for deviations in the gravitational inverse-square law. The outcomes of this research can also have implications for the semiconductor, laser, and quantum computing communities, as correlations between mechanical loss and other loss mechanisms are explored. Additionally, this collaboration between materials science and gravitational wave communities promotes education and diversity, providing research opportunities for students at different education levels and advancing the participation of women and underrepresented minorities.This project aims to develop mirror coatings that meet the mechanical and optical requirements for implementation in CE. Through extending the length of the interferometer arms from the current 4 km to 20 and/or 40 km systems, CE's observational reach will be significantly expanded. To fully utilize this infrastructure, improvements are necessary in the mirror coatings' mechanical loss and thermal noise reduction. The CCR combines groups working on coating deposition, characterization of atomic structure and macroscopic material properties, and computational modeling. These components are often performed by three diverse communities that work in relative isolation from each other. The strength of the CCR and its promise for accelerating discoveries arises from close integration of these communities focusing on a unified research goal. Since the formation of the CCR in 2017, the collaboration has become a knowledge repository for gravitational wave detector coatings research, making significant progress on all the proposed research directions, including uncovering atomic structural motifs associated with room temperature vs cryogenic mechanical losses, using that understanding to develop Ti:GeO2 coatings that can meet the requirements for Advanced LIGO + (A+). Going forward research efforts include the development of improved amorphous coatings and crystalline AlGaAs coatings. The project will investigate atomic structural motifs associated with mechanical losses at different temperatures, aiming for at least a two-fold reduction in thermal noise compared to Advanced LIGO + coatings. CCR contributions have implications for precision measurement, impacting various fields and potentially benefiting the semiconductor, laser, and quantum computing communities. Overall, this research advances the field of gravitational wave detection, supports education at multiple levels, and promotes diversity within the physical sciences.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.