Announcements 2/1/12
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Prayer
Exam 1 review sheet
Schedule adjustment
Reading Quiz
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What is the difference between a Fabry-Perot
etalon and a Fabry-Perot interferometer?
a. The etalon has an adjustable spacing
between the two parallel surfaces.
b. The interferometer has an adjustable
spacing between the two parallel surfaces.
Reading Quiz
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Increasing the coefficient of Finesse F will
a. Make the peaks of a Fabry-Perot
interferometer sharper
b. Make the peaks of a Fabry-Perot
interferometer more blurry
c. Change the spacing of the peaks
d. Do nothing to the peaks
Reading Quiz
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Which of the following was not mentioned in
the book as something that could be varied
to allow you to see Fabry-Perot fringes
(transmission peaks)?
a. Angle going through the
etalon/interferometer
b. Diameter of the light beam
c. Spacing between the partial reflectors
d. Wavelength of the light
Symmetric case
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material 0 = material 2
Plots of T02
Fig. 4.7
Fig. 4.9
F changed by changing d
How wide is the peak?
Thought question (not graded)
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Suppose you want to make your transmission
peak as tall and narrow as possible. You
should choose partial reflectors with:
a. very high reflectivity
b. very low reflectivity
F changed by changing q1
Fig. 4.10
Fig. 4.11
Fig. 4.12
F changed by changing l
Fig. 4.13
Two nearby wavelengths sent through
simultaneously.
Fig. 4.14
Reading Quiz
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The maximum Dl that can be accurately
measured is called the free _______ range.
a. band
b. experiment
c. resolution
d. spectral
e. wavelength
Odds and ends: when used for wavelengths…
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Width of peak: lFWHM
Separation between peaks: DlFSR
“Resolving power”: RP
“Reflecting finesse”, or “finesse”: f
(not same as “coefficient of finesse” F )