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Detailed analysis of MSE spectra

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where M m is the Müeller matrix for a mirror, M P EM1 and M P EM2 are the Müeller matrices for<br />

the first and second photoelastic modulators, M p is the Müeller matrix for a static polarizer<br />

at 22.5 o , and S v is the Stokes vector for the partially polarized light incident on the mse<br />

diagnostic:<br />

⎡<br />

⎤<br />

I b + I 0<br />

I<br />

S v = 0 cos(2γ)<br />

⎢<br />

⎥<br />

(17)<br />

⎣ I 0 sin(2γ) ⎦<br />

0<br />

where I 0 is the intensity <strong>of</strong> the polarized light (polarized at an angle γ to the horizontal) and<br />

I b is the intensity <strong>of</strong> the background, unpolarized light. The Müeller matrix for the mirror<br />

is<br />

⎡ r m+1 r m−1<br />

⎤<br />

0 0<br />

2 2 r m−1 r m+1<br />

0 0<br />

M m = ⎢ 2 2 √ √ ⎥<br />

(18)<br />

⎣ 0 0 rm cos(δ) rm sin(δ)<br />

0 0 − √ ⎦<br />

√<br />

r m sin(δ) rm cos(δ)<br />

The Müeller matrices for the PEMs at 0 o and 45 o are:<br />

⎡<br />

M P EM1 = ⎢<br />

⎣<br />

⎡<br />

M P EM2 = ⎢<br />

⎣<br />

1 0 0 0<br />

0 cos(A) 0 − sin(A)<br />

0 0 1 0<br />

0 sin(A) 0 cos(A)<br />

1 0 0 0<br />

0 1 0 0<br />

0 0 cos(B) sin(B)<br />

0 0 − sin(B) cos(B)<br />

⎤<br />

⎥<br />

⎦<br />

⎤<br />

⎥<br />

⎦<br />

(19)<br />

(20)<br />

and the PEM for a fixed polarizer at 22.5 o is<br />

⎡<br />

M p = 1 ⎢<br />

4 ⎣<br />

√ √<br />

√<br />

2 2 2 0<br />

√ 2 1 1 0<br />

2 1 1 0<br />

0 0 0 0<br />

⎤<br />

⎥<br />

⎦<br />

(21)<br />

Relationship <strong>of</strong> Measured Intensities to Polarization Angle<br />

I used Maple to carry out the matrix multiplication. The output intensity, taken from<br />

the first component <strong>of</strong> the output Stokes vector, is<br />

[<br />

4I net = (I b + I 0 ) 1 + r m + r ]<br />

m − 1<br />

√ (cos(A) + sin(A) sin(B))<br />

2<br />

[<br />

+I 0 cos(2γ) r m − 1 + r ]<br />

m + 1<br />

√ (cos(A) + sin(A) sin(B))<br />

2<br />

+I 0 sin(2γ) √ 2r m [cos(δ) cos(B) + sin(δ)(sin(A) − sin(B) cos(A))] (22)<br />

39

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