Since we need to find the change in refractive index with respect to the propagation direction, does it really need a variable angle ellipsometer?, so that change in angle results in change in propagation direction?
What what I am using right now is a fixed angle ellipsometer? what is the option then
Dear Ms. Suresh,
May I ask what is your sample substrate - is it opaque or transparent? In simple case, eg. if you want to calculate birefringence of glass samples, you can use transmission measurements in two steps: first measure with ellipsometer in straight-line (the polarizer and the analyzer arms pointing to each other without the sample), then measure in same configuratiom but place the sample in between the ellipsometer arms (illuminate through the sample).
Then the Birefringence can be calculated based on the measured ellipsometric "Delta" values, vs. wavelength by using the following formula:
Birefringence [nm/cm] = (Delta2 [°] - Delta1 [°] ) * 3.3 [nm/°] / GlassThickness [cm]
@Peter Basa:
I should have more precise while asking question. The sample is Cu coated on glass (opaque) and what we are using is reflection ellipsometry , not the transmission one.
So how can we do it?
You can simply rotate the sample and then do the anisotropic measurement. The change in the p component to s component and s to p will vary with the angle of incidence.
@ Mukul Bhatnagar : How is it possible to rotate a sample on a fixed table. My sample is flat . The other option you said, p and s will vary with angle, but the challenge is that, it is a fixed angle ellipsometer.
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