According to the basic theory of electromagnetism, transmission and reflection for different media are mentioned.
If it is vertically incident from medium N1 to N2
Reflectivity = [(n2-n1) / (N1 + N2)] ^ 2
Penetration rate = 4n1n2 / (N1 + N2) ^ 2
Example explanation:
If the refractive index of air is 1.0, the refractive index of coating NC (e.g. 1.5), and the refractive index n (e.g. 1.8) (1) of glass enter the glass directly from air
Penetration rate = 4 × one × 1.8 / ( 1+1.8 )2=91.84%
(2) Penetration rate of air entering the coating and then entering the glass = [4 × one × 1.5 / ( 1+1.5 )2] × [ 4 × one point five × 1.8 / ( 1.5+1.8 )2]=95.2%
It can be seen that coated glass will increase light transmittance. In addition, according to this formula, we can calculate the light penetration on both sides of the lens. It is found that even a perfect lens (refractive index 1.8) has a transmittance of about 85%. If a coating is added (refractive index 1.5), the transmittance can reach 91%. The importance of visible optical coating.
