The fundamentals of Light, Refraction and Optics are reviewed in this brief informative presentation

1. Light, Refraction, and
Optics
Kopp Glass, Inc.
Research & Engineering Dept.
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2. What is Light?
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Light is the visible portion of the spectrum visible to the naked eye.
The visible wavelengths are from 380nm to 780nm.
White light is composed of multiple colors.
Colored light is a more narrow spectrum or white light filtered.
Light exists in tiny packets called photons.
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Photons carry electromagnetic radiation.
ER is a form of energy exhibiting wave-like behavior.
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3. Sources of Light
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The sun – 40% of its light is visible
Fire (or something burning)
Incandescent bulb – 10% of its light is visible
Light Emitting Diodes
Gas Discharge – Neon, Mercury Xenon
Chemical Luminescence – glow sticks
Bioluminescence – Fireflies and certain types of fish
Phosphorescence – energy is absorbed by a
substance is released relatively slowly in the form of
light
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4. Speed of Light
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1926 Albert Michelson measured the speed of light to
be 299,796,000 m/s by using a series of mirrors in the
mountaintops of California
~186,282 miles per second. Sunlight takes 8 minutes
and 19 seconds to reach the earth.
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5. Refraction
Refraction - is the change
in direction of a wave due
to a change in its speed.
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Observed when
passing from one
medium to another.
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The straw appears
bent due to the
refraction of light from
water to air.
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6. Refraction
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Is represented by “nD” which is
the velocity of light in a vacuum /
velocity of light in medium
For example, the refractive index
of water is 1.33, meaning that
light travels 1.33 times as fast in a
vacuum as it does in water.
Refractive indices are usually
measured with a refractometer
using a yellow sodium light source
with wavelength of 589.3 nm

7. Index of Refraction
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Glass
Borosilicate – 1.49
Soda Lime – 1.53
Phosphate – 1.64
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Other Materials
 Air – 1.00
 Water – 1.33
 Diamond – 2.42
 Eye lens 1.36
 Fatty Tissue – 1.46
 Brain – 1.36

8. Refraction
Change in refractive index with increasing wavelengths
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9. Refraction
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10. Refraction
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What is it used for?
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Focusing Light
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Spreading light
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Diffusing light
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Fiber Optics
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11. Refraction
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Snells’s Law
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is a formula used to describe the relationship between the angles of incidence
and refraction.
Snell's law states that the ratio of the sines of the angles of incidence and
refraction is equivalent to the ratio of phase velocities in the two media, or
equivalent to the opposite ratio of the indices of refraction.
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12. Optics
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Optics is the branch of physics which
involves the behavior and properties of
light including its interactions with
matter.
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Matter can include liquids, gases, solids,
optical components such as lenses and
mirrors.
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13. Optics
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Types of lenses:
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Lenses are classified by the curvature of the
two optical surfaces. The four basic types
are:
 Concave
 Convex
 Plano
 Fresnel
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14. Concave Lens
At least one lens surface is
curved inward.
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15. Convex Lens
At least one surface
of the lens is curved
out such as a
magnifying glass.
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16. Plano Lens
If one of the surfaces is
flat it is plano-convex
or a plano-concave
lens.
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17. Fresnel Lens
A lens exhibiting the
same focus as an
aspheric lens.
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Easier to manufacture.
Less weight.
Thinner.