Harald Lück, AEI Hannover 1 GWADW- May, 10-15, 2009 EU contract #211743

´06´07´08´09´10´11´12´13´14´15´16´17´18´19´20´21´22 Virgo GEO LIGO LISA E.T. Virgo+ E-LIGO Advanced Virgo GEO HF Advanced LIGO DSPCP Construction Comm. Hanford Livingston Launch Transfer data data You are here 1st Generation2nd Generation 3rd Gen. GW Timelines Site Prep.

 Interferometer size  As big a finances allow? How big is that?  Over-ground vs under-ground (J. Harms, Jo Van der Brand, D. Rabeling)  Will low frequency performance goals really require underground operation ?  Low frequency suspensions (R. Nawrodt)  Newtonian Noise  Cryogenic operation ( W. Johnson, K. Kuroda )  Is cryogenics really needed to achieve the goals or is room temperature sufficient (at least for high frequencies) ?  Non gaussian beams (A. Freise)  QND tricks (H. Müller-Ebhardt)  Xylophone: collocated multi-narrowband vs single- broadband detector (S. Hild, R. DeSalvo) GWADW - May, 10-15,

 Substrate material: Silicon  Gratings & wave-guide coatings (H. Lück)  Quantum noise:  Squeezing (A. Khalaidovski)  Laser (N. Man) GWADW - May, 10-15,

5 Nawrodt et al.

GWADW - May, 10-15, Vanishing 20k & 125K Low thermal low temp. Fused silica 2E-5 / 300 K No thermoelastic noise Temperature [K] Dn/dT

Thermal conductivity Silicon Specific heat Silicon GWADW- May, 10-15,

Thermal conductivity fused Silica Specific heat Silicon / fused silica GWADW- May, 10-15, /10 1E4

GWADW - May, 10-15, from M. Green and M. Keevers, Optical properties of intrinsic 300K, Progress in Photovoltaic research and Applications, Vol. 3, (1995) Wikipedia.com Max. Diameter currently 450mm

GWADW - May, 10-15,

 Refractive index of 1550nm ~ 300K  Refractive Index of SiO 2 ~ 1.44  fewer layers needed due to difference in refractive indeces GWADW - May, 10-15, Si SiO 2 Si Coating SiO 2 Si Substrate

GWADW - May, 10-15, SiO 2 Coating SiO 2 Si SiO Si SiO Substrate High absorption of SiO might be a problem for SiO 2 coatings on Silicon substrates

13 substrate Monolithic 100% reflection “coating” [Brückner et al., Opt. Lett., 33, 264 (2008) ]

14 R > 99.8%, private communication, IAP Jena, R. Schnabel

15 cryst. quartz,  3“  12 mm, Hz Mechanical losses of gratings Nawrodt et al., New Journal of Physics 9 (2007) 225

16 Extracted coating/grating losses Nawrodt et al., New Journal of Physics 9 (2007) 225

GWADW - May, 10-15,

GWADW - May, 10-15, nm Vahlbruch et al. PRL 100, (2008)

GWADW - May, 10-15, Chelkowski et al., PRA 75, (2007) 1064 nm Shot noise Squeezed noise electronic darknoise

GWADW - May, 10-15, nm Mehmet et. al.: arXiv: v1 [quant-ph]

GWADW - May, 10-15,

 Solid state laser:  laser diode pumped solid state laser (AdvLIGO):  210W Nd:YAG, less than 12% in higher order modes, almost finished design for reliable long-term operation  3 E-9 /sqrt(Hz) power 10Hz, rf noise: 1dB above SN of 9 MHz  fibre laser:  ytterbium doped photonic crystal fiber amplifier using a single- frequency Nd:YAG non-planar ring oscillator seed source  148W, less than 8% in higher order modes  13 November 2006 / Vol. 14, No. 23 / OPTICS EXPRESS GWADW - May, 10-15,

 Solid state laser:  -  fibre laser:  Erbium fibre laser, ~2 W, poor reliability GWADW - May, 10-15,

 1064 nm:  Reach 1kW within next 5 years  RIN < 1 E-9 / √ Hz  1550 nm:  150 W within next few years GWADW - May, 10-15,

2022

GWADW- May, 10-15,

GWADW- May, 10-15, Wavelength, µm Refractive Index Wavelength, µm Refractive Index Wavelength, µm Refractive Index

S. Hild et al, GWADW- May, 10-15,