Scattering loss in precision metrology due to mirror roughness
Optical losses degrade the sensitivity of laser interferometric instruments. They reduce the number of signal photons and introduce technical noise associated with diffuse light. In quantum-enhanced metrology, they break the entanglement between correlated photons. Such decoherence is one of the primary obstacles in achieving high levels of quantum noise reduction in precision metrology. In this work, we compare direct measurements of cavity and mirror losses in the Caltech 40 m gravitational-wave detector prototype interferometer with numerical estimates obtained from semi-analytic intra-cavity wavefront simulations using mirror surface profile maps. We show a unified approach to estimating the total loss in optical cavities (such as the LIGO gravitational detectors) that will lead towards the engineering of systems with minimum decoherence for quantum-enhanced precision metrology.
Published by Optica Publishing Group under the terms of the Creative Commons Attribution 4.0 License. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI. Received 7 February 2022; revised 31 March 2022; accepted 5 April 2022; posted 5 April 2022; published 27 April 2022. We acknowledge support from GariLynn Billingsley and Liyuan Zhang for supplying mirror surface maps and TIS measurements, and the many valuable conversations we have had with the Optics Working Group in the LIGO Scientific Collaboration. This material is based upon work supported by the National Science Foundation's (NSF's) LIGO Laboratory, which is a major facility fully funded by the NSF. Funding: National Science Foundation (PHY-0823459, PHY-1764464); Science and Technology Facilities Council (ST/V001019/1, ST/V005693/1); Australian Research Council (CE170100004, DE210100550). Data availability: Data underlying the results presented in this paper are not publicly available at this time but may be obtained from the authors upon reasonable request. The authors declare no conflicts of interest.
Submitted - 2201.05640.pdf
Published - josaa-39-5-969.pdf