How to Calculate 4-Stokes Parameters
- 1). Create a light beam, if necessary. That is, if the source is not directional, put an aperture in place to select a well-defined section on which to perform the measurements.
- 2). Measure the intensity of the beam before entering the region of interest, and record it as I0.
- 3). Measure the intensity of the beam at the end of the region of interest, and record it as I1.
- 4). Put a linear polarizer in the beam, with the axis oriented horizontally. Measure the intensity and record it as Ih.
- 5). Rotate the linear polarizer so that its axis is at 45 degrees relative to the horizontal. Measure the intensity and record it as Ia.
- 6). Insert a quarter-waveplate in front of the linear polarizer, with its fast axis aligned horizontally. Measure the intensity and record it as Ic.
- 7
Once the measurements are made, calculating the Stokes parameters is simple algebra.Jupiterimages/Photos.com/Getty Images
Calculate the four Stokes parameters with the measurements recorded in Steps 2 through 6.
S0 = I1/I0
S1 = ((2 * Ih) / I0) - S0
S2 = ((2 * Ia)/I0) - S0
S3 = ((2 * Ic)/I0) - S0
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