Announcements 3/2/12
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Prayer
Wednesday is exam 2 review
a. On Monday I’ll pass around a sign-up sheet,
like last time. Please look over the exam
review problems before class and have a few
in mind that you could sign up for.
Review
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What Dr. Peatross should have taught you
Review Quiz (ungraded)
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“Quadratic dispersion” refers to:
a. k being a quadratic function of w
b. w being a quadratic function of k
Review Quiz (ungraded)
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The book defines a quantity T  t 1  F 2
where F is a complicated function relating to the phase
of the pulse as it emerges from the material. What
physical significance does t have?
a. It is the period of oscillations as the pulse enters the
material.
b. It is the period of oscillations as the pulse exits the
material.
c. It is the temporal width of the pulse as it enters the
material.
d. It is the temporal width of the pulse as it exits the
material.
Review Quiz (ungraded)
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Same situation: T  t 1  F 2
What physical significance does T have?
a. It is the period of oscillations as the pulse
enters the material.
b. It is the period of oscillations as the pulse
exits the material.
c. It is the temporal width of the pulse as it
enters the material.
d. It is the temporal width of the pulse as it
exits the material.
Sections 7.4, 7.5
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Do FT of E(t) to get frequency components, E(w)
Apply eikDr to find relative phase differences for
each w
Add all frequency components back together to get
new E(w)
Do IFT to get new E(t)
Given on exam:
pulse delayed
pulse reduced if kimag  0
not given:
assume kimag  0
envelope travels at vg; width ~ T
pulse reduced
Review Quiz (ungraded)
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In a typical Michelson interferometer setup, the
electric field at the detector is the sum of two
electric fields, one from each path.
a. true
b. false
Review Quiz (ungraded)
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In an interferometer, the “fringe visibility” refers
to:
a. closeness/separation of fringe peaks
b. height/depth of fringe peaks
c. the wavelengths which contribute to fringes
Sections 8.1-8.2
Given on exam:
not given:
Review Quiz (ungraded)
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In a typical interferometer, the connection
between coherence time and coherence length
is:
a. c  ct c
b. c  vgroupt c
c. c  v phaset c
Example: Gaussian pulse
Reading Quiz
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In an interferometer, if you can measure the
interference pattern as a function of t, you can
deduce the power spectrum I(w) from your
result.
a. True
b. False
Fourier Spectroscopy