Reflective coatings on mirror bodies are key elements of gravitational wave detectors and are a topic of intense research in the community. Two classes of coatings are currently studied namely a broad range of amorphous compounds and a few crystalline materials. The latter group consists of AlGaAs / GaAs and AlGaP / GaP.
In this presentation, the potential of crystalline oxides coatings is...
Substrate-transferred crystalline coatings made from aluminum gallium arsenide (AlGaAs) have lower thermal noise than the ion beam sputtered amorphous oxides currently used in ground based gravitational wave detectors. AlGaAs coatings also exhibit excellent optical properties and both thermal noise and optical performance has been successfully utilized in other precision optics applications. ...
In the current development of optical coatings for high precision instruments like GW interferometers thermal Brownian noise currently pose a limiting factor on the performances obtainable. In particular in the VIRGO experiment, in the 50-300 Hz region, thermal brownian noise act as the dominant contribution.
Since the Brownian noise is commonly attributed to the existence of many local...
Next generation gravitational wave detectors will provide further insight into the Universe thanks to their improved sensitivity. Low thermal noise mirror coatings play an important role in realizing such gravitational wave detectors as coating thermal noise is one of the limiting noise sources in the most critical frequency region.
Crystalline coatings, which have demonstrated low thermal...
Low thermal noise optical coatings are a key part of the design of current and future gravitational wave detectors. Coating thermal noise limits detector sensitivity in the mid range, about 50-300 Hz, where GW detectors are the most sensitive. Tetrahedral metal dioxides, such as silica (SiO2), have been shown to be the most promising materials for low loss amorphous coatings. We present...
Mechanical loss and thermal noise from both the test mass substrates and their coatings are important factors in the sensitivity of current gravitational wave detectors The next generation of gravitational wave detector are proposed to operate at low temperatures, requiring a change in test mass material and coatings designed to work at higher wavelengths. Silicon has been proposed as an...
Cooling mirrors to cryogenic temperatures has been proposed as a strategy to improve the sensitivity of gravitational waves detectors (GWD). The effects of low temperatures on the optical response of mirrors have to be evaluated; additionally, important issues - such as the formation of an ice layer on the surface of mirrors - must be carefully studied to assess their impact on the GWD...
