Download lecture 36 - waves in 3 dimensions, optical devices

Announcements 11/22/10




Prayer
No office hours tomorrow (neither TA nor I), even
though we do have class.
Exam 3 starts Tuesday after the break.
Lab 10 (final lab) going on right now. Due the
Tuesday after the break.
Reading quiz

Which of the following is NOT true of the
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 one dimension it reduces to the wave
number k.
Waves in 3-dimensions

Plane waves
a. polarization

Wave vector
a. direction of wave

Spherical waves
Student-designed problem






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


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
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
only)
(light,
electrical,
etc.)

Principal components:
1.
2.
3.
4.
5.
Gain medium
Laser pumping energy
High reflector
Output coupler
Laser beam
light

Green laser pointer
1. Gain medium
2. Laser pumping
energy
3. High reflector
4. Output coupler
5. Laser beam
More Wikipedia
More Wikipedia
Circular Polarization
Remember these pictures?
Pictures from Wikipedia
Optical Retarders, aka “Wave plates”
Calcite crystal:


Quartz, SiO2: no = 1.544, ne = 1.553
Calcite, CaCO3: no = 1.658, ne = 1.486
Pictures from Wikipedia
Optical Modulators


Electro-optic modulator
Acousto-optic modulator
AOM
EOM
Field changes
vertical index of
refraction
www.newport.com
wikipedia
That’s All! (for optics)

Survey (right now) about exam 3 review
session times for Monday next week