Excess Noise and Photoinduced Effects in Highly Reflective Crystalline Mirror Coatings

authored by: Jialiang Yu, Sebastian Häfner, Thomas Legero, Sofia Herbers, Daniele Nicolodi, Chun Yu Ma, Fritz Riehle, Uwe Sterr, Dhruv Kedar, John M. Robinson, Eric Oelker, Jun Ye
Abstract: Thermodynamically induced length fluctuations of high-reflectivity mirror coatings put a fundamental limit on sensitivity and stability of precision optical interferometers like gravitational-wave detectors and ultrastable lasers. The main contribution - Brownian thermal noise - is related to the mechanical loss of the coating material. Al0.92Ga0.08As/GaAs crystalline mirror coatings are expected to reduce this limit. The first measurements of cryogenic silicon cavities revealed the existence of additional noise contributions exceeding the expected Brownian thermal noise. We describe a novel, nonthermal, photoinduced effect in birefringence that is most likely related to the recently discovered birefringence noise. Our studies of the dynamics and power dependence are an important step toward uncovering the underlying mechanisms. Averaging the anticorrelated birefringent noise results in a residual noise that is shown to be substantially different from Brownian thermal noise. To this end, we develop a new method for analyzing the coating noise in higher-order transverse-cavity modes, which makes it possible for the first time to determine the contribution of Brownian thermal noise to the total cavity noise. The new noise contributions must be considered carefully in precision interferometry experiments using similar coatings based on semiconductor materials.
External Organisation(s): Physikalisch-Technische Bundesanstalt PTB
JILA
University of Glasgow
Type: Article
Journal: Physical Review X
Volume: 13
ISSN: 2160-3308
Publication date: 03.10.2023
Publication status: Published
Peer reviewed: Yes
ASJC Scopus subject areas: General Physics and Astronomy
Electronic version(s): https://doi.org/10.1103/PhysRevX.13.041002 (Access: Open)

BibTeX

@article{126cc640058b4ce7a926b9e7d329de1b,
title = "Excess Noise and Photoinduced Effects in Highly Reflective Crystalline Mirror Coatings",
abstract = "Thermodynamically induced length fluctuations of high-reflectivity mirror coatings put a fundamental limit on sensitivity and stability of precision optical interferometers like gravitational-wave detectors and ultrastable lasers. The main contribution - Brownian thermal noise - is related to the mechanical loss of the coating material. Al0.92Ga0.08As/GaAs crystalline mirror coatings are expected to reduce this limit. The first measurements of cryogenic silicon cavities revealed the existence of additional noise contributions exceeding the expected Brownian thermal noise. We describe a novel, nonthermal, photoinduced effect in birefringence that is most likely related to the recently discovered birefringence noise. Our studies of the dynamics and power dependence are an important step toward uncovering the underlying mechanisms. Averaging the anticorrelated birefringent noise results in a residual noise that is shown to be substantially different from Brownian thermal noise. To this end, we develop a new method for analyzing the coating noise in higher-order transverse-cavity modes, which makes it possible for the first time to determine the contribution of Brownian thermal noise to the total cavity noise. The new noise contributions must be considered carefully in precision interferometry experiments using similar coatings based on semiconductor materials.",
author = "Jialiang Yu and Sebastian H{\"a}fner and Thomas Legero and Sofia Herbers and Daniele Nicolodi and Ma, {Chun Yu} and Fritz Riehle and Uwe Sterr and Dhruv Kedar and Robinson, {John M.} and Eric Oelker and Jun Ye",
note = "Funding information: We acknowledge support by the Project 20FUN08 NEXTLASERS, which has received funding from the EMPIR programme cofinanced by the Participating States and from the European Union{\textquoteright}s Horizon 2020 Research and Innovation Programme, and by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) under Germany{\textquoteright}s Excellence Strategy–EXC-2123 QuantumFrontiers, Project-IDs No. 390837967, No. SFB 1227 DQ-mat, and No. 274200144. This work is partially supported by the Max Planck-RIKEN-PTB Center for Time, Constants and Fundamental Symmetries. This work is also supported by NIST, DARPA, AFRL, and JILA Physics Frontier Center (NSF Grant No. PHY-1734006).",
year = "2023",
month = oct,
day = "3",
doi = "10.1103/PhysRevX.13.041002",
language = "English",
volume = "13",
journal = "Physical Review X",
issn = "2160-3308",
publisher = "American Physical Society",
number = "4",
}