Effect of heat treatment on mechanical dissipation in Ta2O5 coatings

I W Martin (1) , R Bassiri (1) , R Nawrodt (1, 2) , M M Fejer (3) , A Gretarsson (4) , E Gustafson (5) , G Harry (6) , J Hough (1) , I Maclaren (1) , S Penn (7) , S Reid (1) , R Route (1) , S Rowan (1) , C Schwarz (2) , P Seidel (2) , J Scott (1) , a L Woodcraft (8, 9)

1 SUPA School of Physics and Astronomy [Glasgow]
2 Institute of Solid State Physics
3 Ginzton Laboratory [Stanford]
4 Embry-Riddle Aeronautical University
5 LIGO Laboratory
6 MIT - Massachusetts Institute of Technology
7 Department of Physics
8 IfA - Institute for Astronomy [Edinburgh]
9 UK ATC - UK Astronomy Technology Centre

Thermal noise arising from mechanical dissipation in dielectric reflective coatings is expected to critically limit the sensitivity of precision measurement systems such as high-resolution optical spectroscopy, optical frequency standards and future generations of interferometric gravitational wave detectors. We present measurements of the effect of post-deposition heat treatment on the temperature dependence of the mechanical dissipation in ion-beam sputtered tantalum pentoxide between 11 K and 300 K. We find the temperature dependence of the dissipation is strongly dependent on the temperature at which the heat treatment was carried out, and we have identified three dissipation peaks occurring at different heat treatment temperatures. At temperatures below 200 K, the magnitude of the loss was found to increase with higher heat treatment temperatures, indicating that heat treatment is a significant factor in determining the level of coating thermal noise.

Mots clés: 05.40.Jc; 61.43.Er; 68.60.Bs; 04.80.Nn; 95.55.Ym; 42.60.Da Scottish Universities Physics Alliance

I W Martin, R Bassiri, R Nawrodt, M M Fejer, A Gretarsson, et al.. Effect of heat treatment on mechanical dissipation in Ta2O5 coatings. Classical and Quantum Gravity, 2010, 27 (22), pp.225020. ⟨10.1088/0264-9381/27/22/225020⟩. ⟨hal-00643038⟩