| 摘要 |
A silicate based composition for optical glass used as a substrate for thin film optical interference filters having a stable transmission band center wavelength and bandwidth has a relatively high coefficient of thermal expansion, high Young's modulus and high optical transmittance in the near infrared (NIR) wavelength range of about 950 nm to about 1600 nm. The coefficient of thermal expansion of the glass composition is adjustable to particular values to result in minimal wavelength shift in filters made by depositing thin films of particular dielectric materials onto a substrate made of the glass, the composition being varied from a preferred baseline composition consisting of about 43.2% SiO2, 7% Al2O3, 12.7% CaO, 7.3% SrO, 7.8% Li2O, 13.2% Na2O, 8.0% K2O, 0.7% ZrO, and 0.1% Sb2O3, the baseline composition having a coefficient of thermal expansion of about 112x10-7/° C. over the temperature range of -30° C. to +70° C., a Young's modulus E of 88.3 Gpa, and an optical transmittance of 90.9% at 1550 nm for an 8 mm thick sample plate.
|
