The indirect method of mesearing medium complex-refractive index which placed in air at the 45°incident angle

When the Rght at the 45° incidence,by pass through the reflection intensity of medium surface which placed in the air,it can use mathematics description of polarizing to show.And it combined with the complex amplitude rs,rp of Fresnel reflection factor when the light reflected at the interface of two transparent dielectric.In the dielectric constant ε between refraction medium and incident medium,there is a equation of rs-rp/1-rs·rp=1-ε/1+ε.From this,can get the complex-refractive index of medium.Its equation is N=rs2+1/(rs+1)2.