RefractionRefraction Refraction

When light bends as it passes from one material to another due to a change in speed

• Optical illusions

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RefractionRefraction Index of Refraction

The ratio of the speed of light in a vacuum to the speed of light in a material

Depends on the wavelength of the light• Short wavelength light has a greater index of

refraction

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RefractionRefraction Snell’s Law

Relation between the light’s path through a material and the material’s index of refraction

ni sin θi = nr sin θr

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RefractionRefraction Why refraction occurs

The least amount of time for the light to travel between two points A and B

• Fermat’s Principle

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RefractionRefraction Total Internal Reflection

Light is completely reflected at the interface between two materials

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RefractionRefraction Total Internal Reflection

Applications: binoculars, diamonds, fiber optics

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RefractionRefraction Dispersion

Each color of light refracts by a different amount due to its wavelength – the speed of light changes

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RefractionRefractionDispersion

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RefractionRefraction

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LensesLenses Lenses

Similar to a set of small prisms• Converging • Diverging

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LensesLenses The human eye

Near point, far point and 20/20 vision

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LensesLenses Laser eye surgery

Nearsightedness, Farsightedness and surgery

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LensesLensesTelescopes

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LensesLenses Telescopes

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LensesLenses Telescopes

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LensesLenses Telescopes

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