 For "θ" greater than the critical angle, the phase shifts on total reflection are deduced from complex values of the reflection coefficients.For completeness, Fig.2 also shows the phase shifts on "partial" reflection, for "θ" "less" than the critical angle.In the latter case, the reflection coefficients for the "s" and "p" components are "real", and are conveniently expressed by "Fresnel's sine law"

and "Fresnel's tangent law"

where "θ" is the angle of incidence and "θ"t is the angle of refraction (with subscript "t" for "transmitted"), and the sign of the latter result is a function of the convention described above.