The limit sensitivity of interferometric gravitational wave antennas is set by the thermal noise in the dielectric mirror coatings. These are currently made of alternating quarter-wavelength high/low index material layers with low mechanical losses. The quarter-wavelength design yields the maximum reflectivity for a fixed number of layers, but not the lowest noise for a prescribed reflectivity. This motivated our recent investigation of optimal thickness configurations, which guarantee the lowest thermal noise for a targeted reflectivity. This communication provides a compact overview of our results, involving nonperiodic genetically-engineered and truncated periodically-layered configurations. Possible implications for the advanced Laser Interferometer Gravitational wave Observatory (LIGO) are discussed.
Optimized multilayer dielectric mirror coatings for gravitational wave interferometers / Agresti, J.; Castaldi, G.; Desalvo, R.; Galdi, V.; Pierro, V.; Pinto, I. M.. - 6286:(2006), p. 628608. (Intervento presentato al convegno Advances in Thin-Film Coatings for Optical Applications III tenutosi a San Diego, CA, usa nel 2006) [10.1117/12.678977].
Optimized multilayer dielectric mirror coatings for gravitational wave interferometers
I. M. Pinto
2006
Abstract
The limit sensitivity of interferometric gravitational wave antennas is set by the thermal noise in the dielectric mirror coatings. These are currently made of alternating quarter-wavelength high/low index material layers with low mechanical losses. The quarter-wavelength design yields the maximum reflectivity for a fixed number of layers, but not the lowest noise for a prescribed reflectivity. This motivated our recent investigation of optimal thickness configurations, which guarantee the lowest thermal noise for a targeted reflectivity. This communication provides a compact overview of our results, involving nonperiodic genetically-engineered and truncated periodically-layered configurations. Possible implications for the advanced Laser Interferometer Gravitational wave Observatory (LIGO) are discussed.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
