Reflectance properties of silicon mirrors with TiO2/SiO2, Ta2O5/SiO2, and Si/SiO2 film systems at 1315 nm are numerically analyzed, and discussed under conditions of normal and 45° tilt angle incidence, respectively. The results show that reflectance properties of TiO2/SiO2 and Ta2O5/SiO2 are similar; theoretical reflectivity is less than 99.95% for 1315 nm laser wavelength. Theoretical reflectivity of Si(c)/SiO2 stack can be more than 99.99%.