Question

what is refractive index of mirror​

Answer 1

The refractive index of the mirror substrate is 1.649. Mean value of r/n is 0.7280 cm2. The refractive index of the mirror substrate is 1.693. The refractive index of the mirror substrate is precisely determined by forming interference pattern from the scattered laser radiation.

Answer 2

A very complex dielectric mirror can reflect up to 99.999% of the light incident upon it, for a narrow range of wavelengths and angles. ... The effect happens when light goes from a medium with a higher index of refraction to one with a lower value (like air).