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ken~flo
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1. Here's the question:
The percent polarization P of a partially polarized beam of light is defined as
P = [Imax - Imin]/[Imax + Imin] x 100
where Imax and Imin are the max and min intensities that are obtained when the light
passes through a polarizer that is slowly rotated. Such light can be considered as the
sum of two unequal plane-polarized beams of intensities Imax and Imin perpindicular to
each other. Show that the light transmitted by a polarizer, whose axis makes an angle
theta to the direction in which Imax is obtained, has intensity
[1 + pcos(2theta)]/[1 + p]
where p = P/100.
I = I# x cos^2(theta) (I# is I naught, or initial intensity)
3. I thought that the intensity would be at a maximum when theta=0 degrees, because
cosine of 0 is 1, so the Intensity of the polarized light would be equal to the intensity
of the light initially, but that doesn't seem to work out to something that resembles
the answer. I also thought that maybe p=cos^2(theta), since it is the fractional
percentage of the initial intensity. I also tried coming up with equations for Imax and
Imin, but I wasn't sure whether or not they would have the same angles and
intensities. Any help with this problem would be greatly appreciated.
The percent polarization P of a partially polarized beam of light is defined as
P = [Imax - Imin]/[Imax + Imin] x 100
where Imax and Imin are the max and min intensities that are obtained when the light
passes through a polarizer that is slowly rotated. Such light can be considered as the
sum of two unequal plane-polarized beams of intensities Imax and Imin perpindicular to
each other. Show that the light transmitted by a polarizer, whose axis makes an angle
theta to the direction in which Imax is obtained, has intensity
[1 + pcos(2theta)]/[1 + p]
where p = P/100.
Homework Equations
I = I# x cos^2(theta) (I# is I naught, or initial intensity)
3. I thought that the intensity would be at a maximum when theta=0 degrees, because
cosine of 0 is 1, so the Intensity of the polarized light would be equal to the intensity
of the light initially, but that doesn't seem to work out to something that resembles
the answer. I also thought that maybe p=cos^2(theta), since it is the fractional
percentage of the initial intensity. I also tried coming up with equations for Imax and
Imin, but I wasn't sure whether or not they would have the same angles and
intensities. Any help with this problem would be greatly appreciated.
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