Refractive Index Control
Light Refraction Through Glass Block
π‘Understanding Light Refraction
Refraction occurs when light travels from one medium to another with a different optical density. The light ray bends due to the change in speed as it enters the new medium. This phenomenon is governed by Snell's Law.
When light enters a denser medium (higher refractive index), it slows down and bends toward the normal. When it exits back to a less dense medium, it speeds up and bends away from the normal. In a rectangular block with parallel surfaces, the exit ray is parallel to the incident ray but laterally displaced.
πSnell's Law of Refraction
Mathematical Relationship
β’ nβ, nβ = refractive indices of the two media
β’ ΞΈβ = angle of incidence (from normal)
β’ ΞΈβ = angle of refraction (from normal)
Entering Denser Medium
β’ Light slows down
β’ Bends toward the normal
β’ Angle decreases
β’ Example: Air β Glass
Entering Less Dense Medium
β’ Light speeds up
β’ Bends away from normal
β’ Angle increases
β’ Example: Glass β Air
π¬Common Refractive Indices
Everyday Materials
Special Materials
π Optical Instruments
- β’ Lenses: Cameras, eyeglasses, microscopes
- β’ Prisms: Binoculars, periscopes, spectroscopy
- β’ Fiber Optics: Internet cables, medical endoscopes
- β’ Telescopes: Astronomical and terrestrial observation
π Natural Phenomena
- β’ Rainbows: Dispersion in water droplets
- β’ Mirages: Atmospheric refraction effects
- β’ Swimming Pools: Objects appear closer/shifted
- β’ Diamonds: Brilliance from high refractive index