Light Dispersion on Prism
Interactive Physics Simulation — Dispersion of White Light
What is Dispersion?
White light is a mixture of different colors. When it passes through a prism, each color bends by a different amount because the speed of light in glass depends on the wavelength (color). This spreading of colors is called dispersion.
Snell's Law
The amount of bending depends on the refractive index (n) of the prism material and the angle of incidence (θ₁). Different wavelengths experience different refractive indices.
Cauchy's Equation
The refractive index varies with wavelength λ. Shorter wavelengths (violet) bend more than longer wavelengths (red), creating the rainbow spectrum.
Visible Spectrum
Key Points
• Red light bends the least (longest λ)
• Violet light bends the most (shortest λ)
• The order of colors is ROYGBIV
• Rainbow colors are pure — they cannot be split further
• A wider prism angle increases dispersion