# Deriving Stokes parameters for polarization

## Homework Statement

Hello i am trying to write the Stokes parameters as the amplitude of the averaged EM-wave

We know the stokes parameters are {I,M,C,S} or {S0,S1,S2,S3} thus a column vector.

And S0 is defined as S0=<E2x0>T+<E2y0>T

S0 i understand how it was derived since Filter 0 is an isotropic filter it doesnt have any direction preference.

But now comes my problem i`m attempting to derive

S1 =<E2x0>T-<E2y0>T

## Homework Equations

Eq1 S0=2I0
Eq2 S1=2I1-2I0

Whereby I1 is the transmitted irradiance through a horizontal polarizing filter.

## The Attempt at a Solution

[/B]
We know I0=(1/2)*(<E2x0>T+<E2y0>T)

and I1=(1/2)*<E2x0>T

Thus if i now substitute I0 and I1 into Eq 2 i get S1=-<E2y0>T where as it is supposed to be

S1=<E2x0>T-<E2y0>T

I think the problem sits in the definitions of I0 and I1 so if you see which thinking step im doing wrong i would appreciate your help.