Titania-doped tantala/silica coatings for gravitational-wave detection
  Reducing thermal noise from optical coatings is crucial to reaching the required sensitivity in next generation interferometric gravitational-waves detectors. Here we show that adding TiO$_2$ to Ta$_2$O$_5$ in Ta$_2$O$_5$/SiO$_2$ coatings reduces the internal friction and in addition present data confirming it reduces thermal noise. We also show that TiO$_2$-doped Ta$_2$O$_5$/SiO$_2$ coatings are close to satisfying the optical absorption requirements of second generation gravitational-wave detectors. 
Gregory M. Harry, Matthew R. Abernathy, Andres E. Becerra-Toledo,   Helena Armandula, Eric Black, Kate Dooley, Matt Eichenfi...