Total internal reflection (TIR) is an extreme form of internal reflection that occurs when light travels from a denser medium to a rarer medium with a higher re...
Total internal reflection (TIR) is an extreme form of internal reflection that occurs when light travels from a denser medium to a rarer medium with a higher refractive index. The refracted light undergoes a complete turnaround, striking the boundary of the two mediums at an angle greater than the critical angle. The critical angle is the angle of incidence at which the refracted light and the reflected light are exactly perpendicular to each other.
When light enters a medium with a lower refractive index from a medium with a higher refractive index, it undergoes total internal reflection. This means that the refracted light is bent back towards the core of the rarer medium. The angle of incidence and the angle of refraction are related by Snell's law: θ_i = θ_r, where θ_i is the angle of incidence and θ_r is the angle of refraction.
The phenomenon of TIR can be observed when light is incident on the boundary between a denser medium, such as glass, and a rarer medium, such as air. The refracted light may strike the retina of the observer, causing the image to appear inverted or blurry. TIR is also used in various applications, such as optical fibers, laser pointers, and microscopes