Fresnel Equations Solver
Fresnel Equations Solver computes reflection/transmission coefficients for light at a dielectric interface.
Formulas Used in Fresnel Equations Solver
The solver computes the reflection and transmission coefficients for light at an interface between two dielectric media:
Fresnel Reflection Coefficients:
\\[ r_s = \frac{n_1 \cos \theta_i – n_2 \cos \theta_t}{n_1 \cos \theta_i + n_2 \cos \theta_t}, \quad r_p = \frac{n_2 \cos \theta_i – n_1 \cos \theta_t}{n_2 \cos \theta_i + n_1 \cos \theta_t} \\]Fresnel Transmission Coefficients:
\\[ t_s = \frac{2 n_1 \cos \theta_i}{n_1 \cos \theta_i + n_2 \cos \theta_t}, \quad t_p = \frac{2 n_1 \cos \theta_i}{n_2 \cos \theta_i + n_1 \cos \theta_t} \\]Snell’s Law:
\\[ n_1 \sin \theta_i = n_2 \sin \theta_t \\]Reflectance and Transmittance:
\\[ R_s = |r_s|^2, \quad R_p = |r_p|^2 \\] \\[ T_s = \frac{n_2 \cos \theta_t}{n_1 \cos \theta_i} |t_s|^2, \quad T_p = \frac{n_2 \cos \theta_t}{n_1 \cos \theta_i} |t_p|^2 \\]Where:
- \\( n_1 \\): Refractive index of incident medium
- \\( n_2 \\): Refractive index of refracted medium
- \\( \theta_i \\): Angle of incidence (degrees)
- \\( \theta_t \\): Angle of transmission (degrees)
- \\( r_s, r_p \\): Reflection coefficients for s- and p-polarized light
- \\( t_s, t_p \\): Transmission coefficients for s- and p-polarized light
- \\( R_s, R_p \\): Reflectance for s- and p-polarized light
- \\( T_s, T_p \\): Transmittance for s- and p-polarized light
Example Calculations
Example 1: Air (n₁ = 1.0) to Glass (n₂ = 1.5), θᵢ = 45°
Input: \\( n_1 = 1.0, n_2 = 1.5, \theta_i = 45^\circ \\)
Result: \\( \theta_t \approx 28.13^\circ, r_s \approx -0.170, r_p \approx 0.106, t_s \approx 0.830, t_p \approx 0.895, R_s \approx 0.029, R_p \approx 0.011, T_s \approx 0.971, T_p \approx 1.048 \\)