Index of Refraction Calculator
Calculate the index of refraction from light speed in a medium.
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Enter the speed of light in the medium in meters per second. The calculator computes the refractive index by dividing the speed of light in vacuum (approximately 3 x 10^8 m/s) by the entered speed.
About Index of Refraction
The index of refraction is a fundamental optical property of a material. It determines how much light slows down and bends when passing through the material. Light travels at its maximum speed in a vacuum (approximately 3 x 10^8 m/s) and slower in all other media. The refractive index governs phenomena like refraction, total internal reflection, and dispersion, and is crucial for designing lenses, optical fibers, and prisms.
Frequently Asked Questions
What is the index of refraction?
The index of refraction (n) is the ratio of the speed of light in a vacuum to its speed in a material. It is always greater than or equal to 1. Higher values mean light travels more slowly in that material.
What are some common refractive indices?
Vacuum: 1.0, Air: 1.0003, Water: 1.33, Glass: 1.5, Diamond: 2.42. The higher the index, the more the material bends light.
How does refractive index relate to Snell's law?
Snell's law uses refractive indices to calculate how light bends at an interface: n1 sin(theta1) = n2 sin(theta2). Light bends toward the normal when entering a denser medium.