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PhysicsCourse 06

Optics

Geometric rays, image formation, interference, diffraction, polarization, and optical instruments.

Core~30 minGrasp Physics
ReflectionRefractionLensesInterferenceDiffractionPolarization
Step 01Course 6 · Optics

Choose the ray picture or the wave picture by scale.

When structures are much larger than the wavelength, light travels approximately along rays. Reflection preserves the angle to the normal; refraction follows Snell's law n1sin⁡θ1=n2sin⁡θ2n_1\sin\theta_1 = n_2\sin\theta_2.

When apertures, edges, or path differences approach the wavelength, phase matters and wave optics is essential. Both pictures are limits of the same electromagnetic theory.