Transcript Physics 123 “Majors” Section Unit 1

Announcements 3/30/11
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Prayer
Exam 3 review session: Thursday, 5-6:30 pm.
Location: room C258 ESC
Exam 3 starts Saturday, goes through next
Saturday.
Exam not written yet… on Friday I’ll be able to
give you some details.
If you used the Tutorial Lab, please rate the
TAs: http://gardner.byu.edu/tas/tutorrating.html
(rating form has photos)
Reading quiz
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Which of the following is NOT true of the 3D
“wave vector”?
a. Its magnitude is equal to 2p/l.
b. In a plane wave it points in the same
direction everywhere in space.
c. In a spherical wave it points in the same
direction everywhere in space.
d. It tells us which way the wave is going.
e. In 1D it reduces to the wave number k.
Waves in 3-dimensions
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Plane waves
a. polarization
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Wave vector
a. direction of wave
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Spherical waves
Student-designed problem: Transverse Wave
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What direction do you want the wave to be
traveling in?
What direction do you want the wave to be
oscillating in?
What wavelength do you want the wave to have?
What do you want the wave’s amplitude to be?
What frequency (or velocity) do you want the wave
to have?
What do you want the overall phase of the wave to
be?
Lasers
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What makes a laser
special? (answers from
class)
Some of my answers:
a. Single wavelength
b. Intense
c. Collimated
d. Coherence (spatial,
temporal) 99.9999999999%
Actual laser spectrum
is over 100 narrower
than the width of the
red line
Laser spectrum
Blackbody spectrum
Image & list from Wikipedia
Lasers
Stimulated
Emission Emission
Absorption
Energy
(light)
(light,
electrical,
etc.)
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Principal components:
1.
2.
3.
4.
5.
Gain medium
Laser pumping energy
High reflector
Output coupler
Laser beam
light
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Green laser pointer
More Wikipedia
5. laser beam
3. high
reflector
1. gain medium
(Nd:YVO4 crystal)
2. laser pumping energy
(808 nm LED beam)
4. output
coupler
More Wikipedia
Circular Polarization
Remember these pictures?
Pictures from Wikipedia
Optical Retarders, aka “Wave plates”
Calcite crystal:
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Quartz, SiO2: no = 1.544, ne = 1.553
Calcite, CaCO3: no = 1.658, ne = 1.486
Pictures from Wikipedia
Optical Modulators
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Electro-optic modulator
Acousto-optic modulator
AOM
EOM
Field changes
vertical index of
refraction
www.newport.com
wikipedia