`alpha(theta_i, n_1, n_2)` for EM waves

$alpha = sqrt(1 - ( n_1 / n_2 sin( theta_i ))^2) / cos( theta_i )$

Enter a value for all fields

This equation calculates $alpha$ (using $theta_i$ , $n_1$ , and $n_2$ ), used in calculating the amplitudes of EM waves striking an interface. For more information and context on this equation, please see the EM waves at the interface of two insulators.

$theta_i$ is the angle between the incident wave and the normal of the interface.
$n_1$ is the index of refract of the first material, described by $n_1 = c/v_1$ .
$n_2$ is the index of refract of the second material, described by $n_2 = c/v_2$

For more information on $theta_i$ , $n_1$ , and $n_2$ , please see the Angles of Reflection and Refraction.