Speaker
Description
In Einstein's general theory of relativity, gravitational waves were initially predicted in 1916. According to him these cataclysmic events produce brief perturbations in spacetime curvature that propagate outward as GW ripples. These waves convey energy in the form of gravitational radiation and move at the speed of light. The Laser Interferometer Gravitational-Wave Observatory (LIGO) uses kilometer-scale Michelson interferometers to measure length changes smaller than one-thousandth of a proton's diameter, which is necessary to detect these incredibly faint signals. The interferometer's mirrors, whose performance is largely dictated by their optical coating technology, are at the centre of this extraordinary sensitivity. This study focused how multi-layer dielectric mirror coatings with ultra-high reflectivity allow LIGO to attain the extraordinary precision needed for gravitational wave detection. We go into the materials used, the strict specifications on optical loss, surface roughness, and mechanical dissipation, and the physical concepts of thin-film interference used to develop these coatings. Nowadays, gravitational wave detectors function as modified Michelson interferometers, with thermal noise from the highly reflective mirror coatings placing a crucial limit on the sensitivity of both present and future devices.
| Condensed Matter Physics | High Energy Physics |
|---|---|
| High Energy Physics | High Energy Physics |
