2 A B C D E F G H I K L M N O P R S T U V W

total internal reflection

Total internal reflection (“TIR”) occurs, when the angle of incidence of a ray propagating from a higher indes medium to a lower index medium exceeds the critical angle.

sin(\theta_{c}) = \frac{n_2}{n_1}

Examples for critcal angles
n_1 \theta_{c}
1.3 50.3°
1.4 45.6°
1.5 41.8°
1.6 37.8°
1.7 36.0°
1.8 33.7°
1.9 31.8°
2.0 30.0°

for an interactive example, see refraction