Details

Autor(en) / Beteiligte

• Pierro, V.
• Fiumara, V.
• Chiadini, F.
• Bobba, F.
• Carapella, G.
• Di Giorgio, C.
• Durante, O.
• Fittipaldi, R.
• Mejuto Villa, E.
• Neilson, J.
• Principe, M.
• Pinto, I.M.

Titel

On the performance limits of coatings for gravitational wave detectors made of alternating layers of two materials

Ist Teil von

• Optical materials, 2019-10, Vol.96, p.109269, Article 109269

Ort / Verlag

Elsevier B.V

Erscheinungsjahr

2019

Link zum Volltext

Quelle

Elsevier ScienceDirect Journals Complete

Beschreibungen/Notizen

• The coating design for mirrors used in interferometric detectors of gravitational waves currently consists of stacks of two alternating dielectric materials with different refractive indexes. In order to explore the performance limits of such coatings, we have formulated and solved the design problem as a multiobjective optimization problem consisting in the minimization of both coating transmittance and thermal noise. An algorithm of global optimization (Borg MOEA) has been used without any a priori assumption on the number and thicknesses of the layers in the coating. The algorithm yields a Pareto tradeoff boundary exhibiting a continuous, decreasing and non convex (bump-like) profile, bounded from below by an exponential curve which can be written in explicit closed form in the transmittance-noise plane. The lower bound curve has the same expression of the relation between transmittance and noise for the quarter wavelength design where the noise coefficient of the high refractive index material assumes a smaller equivalent value. An application of this result allowing to reduce the computational burden of the search procedure is reported and discussed. •Solution of the design optimization problem of two-materials coatings for Gravitational Wave detectors.•Pareto front computation by (state of art) multi-objective optimizations algorithm (Borg MOEA).•Analytic expression bounding the Pareto fronts.•Noise reduction in realistic Gravitational Waves detectors.