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Thermal noise limit

Parameters needed for thermal noise calculation

Literature:

  • [1] J. Opt. Soc. Am. B pp 914, Vol. 27, No. 5/May 2010
  • [2] NATURE PHOTONICS Vol.7, 644 (2013)
  • [3] Optics Letters, Vol. 40, Iss. 9, p. 2112 (2015).
Description Material Parameter name Value Comment
Boltzmann constant kb 1.38064852 × 10-23 m2 kg s-2 K-1
Temperature (K) T 300
Poisson Ratio of substrate Fused Silica σsb 0.16 Fused Silica substrtae [1]
Poisson Ratio of coating AlGaAs σc 0.32 AlGaAs coating [2]
Young's modulus of substrate Fused Silica Esb 72.7 Gpa Fused Silica substrtae [1]
Young's modulus of spacer ULE Esp 67.6 Gpa ULE Spacer [1]
Young's modulus of coating AlGaAs Ec 100 Gpa AlGaAs coating [2]
Length of cavity L 0.48 m Sr Beast [3]
Spacer radius Rsp 0.045 m Sr Beast [3]
Central bore radius of spacer rsp 0.0065 m Sebastian Häfner Thesis page 83
Thickness of coating AlGaAs D 6.83*10-6 m AlGaAs coating [2]
1/e2 mode radius on the mirror w 0.000488 m for Mirror 1
0.000677 m for Mirror 2 		Mode calculations
Effective coefficient of thermal expansion for substrate αsb 1.2* 10-6 K-1 Fused Silica substrtae [2]
Effective coefficient of thermal expansion for coating αc 1.68* 10-5 K-1 AlGaAs coating [2]
Effective thermorefractive coefficient for coating βc 5*10-5 AlGaAs coating [2]
Thermal conductivity for substrate κsb 1.38 W/Km Fused Silica substrate [2]
Thermal conductivity for coating κc 62.9 W/Km AlGaAs coating [2]
Heat capacity per unit volume for substrate Csb 1.71*106 J/Km3 Fused Silica substrate [2]
Heat capacity per unit volume for coating Cc 1.64*106 J/Km3 AlGaAs coating [2]