Working Principle of Light Pipes
Refraction and reflection: when light enters the light pipe, its direction is altered by refraction at the material interfaces.
Total Internal Reflection (TIR): when the incident angle exceeds the critical angle, light undergoes TIR inside the pipe, enabling long-distance transmission with minimal loss.
Light extraction control: microstructures on the sidewalls (e.g., V-grooves, prismatic patterns) disrupt TIR, causing controlled scattering to achieve uniform illumination.