Refractive Index

Dimensionless ratio n describing the phase velocity of light in a medium relative to vacuum (n = c/v), which determines the angle of refraction at interfaces via Snell's law and influences optical propagation.

Dimensionless ratio n = c/v that compares the speed of light in vacuum (c) to its phase velocity v in a material at a specified wavelength and temperature; equivalently the parameter appearing in Snell's law that governs refraction at interfaces.