Prism Dispersion - Interactive Light Dispersion Simulator

Explore how white light separates into rainbow colors through a prism. Interactive physics simulation with Snell's law and Cauchy's equation.

Understanding Prism Dispersion

Dispersion is the phenomenon where white light separates into its constituent colors when passing through a prism. This occurs because different wavelengths of light travel at different speeds in the prism material, causing them to refract at different angles.

Physical Laws and Formulas

Snell's Law

n₁sin(θ₁) = n₂sin(θ₂)

Describes how light bends when passing between media with different refractive indices.

Cauchy's Dispersion Equation

n(λ) = A + B/λ²

The refractive index depends on wavelength, where A and B are material-specific constants.

Deviation Angle

δ = i + e - A

Total deviation depends on incident angle (i), emergence angle (e), and prism apex angle (A).

Why Dispersion Occurs

  • Different wavelengths have different refractive indices
  • Shorter wavelengths (blue/violet) are refracted more than longer wavelengths (red)
  • The refractive index generally decreases as wavelength increases
  • This wavelength-dependence is called "normal dispersion"

Applications

  • Spectroscopy: Analyzing light composition from stars and materials
  • Rainbows: Natural dispersion in water droplets
  • Optical Instruments: Cameras, telescopes, and binoculars
  • Prism Binoculars and Periscopes: Image erection and brightness

Historical Context

In 1666, Isaac Newton demonstrated that white light from the sun is composed of all colors of the visible spectrum. His experiments with prisms revolutionized our understanding of light and color, laying the foundation for modern optics.

The Visible Spectrum

Red ~700nm, longest visible wavelength
Orange ~620nm
Yellow ~580nm
Green ~530nm
Cyan ~490nm
Blue ~470nm
Violet ~400nm, shortest visible wavelength