Wave theory of light
Intermediate
Huygens' principle explains reflection and refraction.
Huygens and Young treated light as waves; Maxwell showed they are electromagnetic. Wave theory explains interference, diffraction and polarisation.
Fringe patterns in thin films.
Particle behaviour appears in photon detection.
In more detail
The wave theory of light, developed by Huygens, Young and Fresnel, explains interference and diffraction. Light is a transverse electromagnetic wave with a definite wavelength.
Real-world uses
- Interference coatings and gratings depend on the wave theory.
- Interferometers measure distances using light waves.
- Physicists explain reflection and refraction with a wave picture, where each point of a wavefront spreads out as a new source.
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Frequently asked questions
Why was the wave theory accepted?
Because it explained interference and diffraction, which the particle theory could not.
Does the wave theory explain photoelectric effect?
No, that required photons, showing light has both wave and particle character.
Why does the wave picture matter?
It explains interference and diffraction, which the ray picture cannot describe.
Related topics in Optics
Astronomical telescope · Reflecting telescope · Camera and f-number · Huygens' principle · Coherent sources · Young's double slit