... one of transparent colorless glass, through wavelength is between 300 nm to 2500 nm, transmissivity is more than 90%. ... 1.0 1.5 1.7,2.0,3.0,3.3,4.0,5.0,6.0,8.0,10.0,12.0,15.0,20.0,mm ... Performance Density ρ 2.23±0.02g/cm32). Thermodynamic Performance Thermal expansion coefficient (0-300) 3.3±0.1×10-6K-1 Softening ... point 820±10°C Strain point 516±10 Caloricity (20-100) 0. ...