Lab 9: Reflection and Refraction
–
–
Law of Reflection
Law of Refraction (Snell’s Law)
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
Index of Refraction
The Critical Angle
Total Internal Reflection
Dispersion
Light Passing through a Window Pane or Prism
How Large does a Mirror Need to be?
Location of Mirror Image
Rainbows
Corner Reflectors
Fiber Optics
Polarization by Reflection
• Light ray
– Originates at a point source
– Travels straight
– Changes direction at interface
• Reflection & refraction in this lab
• Object
– Point source of light rays
• Image
– Apparent convergence point of light rays from object
• Draw diagrams involving
– Light rays
– Interface
– Angles
• Estimate angles to the tenth of a degree
– Take several measurements and then average them
Light Rays
• indicated as arrows
• from object  extend outward
Light Rays
white light
light unit:
a ray of light made by a slit
Interface
normal :
direction perpendicular to interface
interface :
boundary between different media
Cross-sectional View
air
medium
Reflection (Specular)
angles measured from normal
angle of incidence (qi )
qi
qr
angle of reflection (qr )
air
mirror
Cross-sectional View
air
Top view
Experiment #1
ray of light
qM
ray of light
qA
Component Line
qA
qM
Experiment #2
Aim light ray at the center of semicircle.
Reflection
qi
qr
qr – qi
(degree)
(degree)
(degree)
0
10

85
Refraction #1
qA
qM
(degree)
(degree)
sinqA
sinqM
sinqA/sinqM (= nglass)
0
N/A
10

85
Use the “degree” mode on your calculator