Transverse-electric Fresnel reflection coefficient
= Transverse-electric Fresnel reflection coefficient
When the permeabilities agree, the signed reflected-to-incident electric-field ratio for polarization normal to the plane of incidence is
$$
r_{\rm TE}
=\frac{n_-\cos\theta_I-n_+\cos\theta_T}
{n_-\cos\theta_I+n_+\cos\theta_T}.
$$
For incidence from lower to higher refractive index it never vanishes.