Seminario en el accelerator – Kirstin Saunders (Universidad de Glasgow)

Ponente: Kirstin Saunders (University of Glasgow)

Titulo: Sub-stoichiometric SiNx Deposited by PECVD for Optical Coatings for Gravitational Wave Detection

Abstract: Highly reflective (HR) optical coatings are vital components in laser interferometers employed for the detection of gravitational waves (GWs). These highly sensitive instruments enforce strict requirements over the properties of the coatings, requiring a reflectance >99.9%, low optical loss < 10ppm, and a low mechanical loss of <10-4 [1,2]. Silicon nitride (SiNx) is an adaptable material proposed for the next generation of gravitational wave detector. It is renowned for its tuneable characteristics and high refractive index (n) ranging from 1.88 to 2.3 at a wavelength of 1550nm. Furthermore, silicon oxynitride (SiOxNy) is being investigated as a low n to complement SiNx in DBR stack; to produce HR coatings and similar to SiNx, also known for its property tuneability [3]. This work focuses on the deposition and characterisation of these thin films including and determine their suitability for the detection of GWs.

[1] S. Reid and I. Martin.,Coatings, vol.6,no.4,p.61,2016, doi: 10.3390/coatings6040061
[2] M. Granata et al., Appl. Opt., vol.59, no.5, p.A229, 2020, doi: 10.1364/AO.377293.
[3] K.Saunders et al.,Appl.Opt.,vol.65, no.5, p. A187, 2026, doi: 10.1364/AO.578011