Optical rotation and linear basis set

AI Thread Summary
The discussion centers on the behavior of polarized light as it passes through optical components, specifically a quarter-wave plate and an optical rotary crystal. It raises the question of whether the orientation of a linear basis set can be altered by the optical rotary crystal when circularly polarized light is used. Participants agree that the optical rotary crystal can indeed rotate the linear basis set, and the extent of this rotation depends on the difference in refractive indices for right and left circular polarizations. The conversation also touches on the mathematical representation of these transformations using Jones matrices, highlighting the differences between linear and circular rotators. Ultimately, the consensus is that the basis set orientation is not fixed and can be influenced by the optical components involved.
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If I have a 45 degree linear polarized light which I then circularly polarize using a 1/4 wave plate and put this through an optical rotary crystal and then using the equivalent 1/4 wave plate but in the reverse oriention, will I get back a 45 degree linear polarized light?

Put another way, as circular polarized light can use a linear basis set 90 degrees out of phase, can the angle of the linear basis set with respect to the 1/4 wave plate orientation be rotated by the optical rotary crystal (while the phase remains circular) or is the basis set orientation always fixed?

I would think the basis set orientation is fixed but just want to make sure.
 
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There is no reason why the basis set orientation ought to be fixed. By my understanding the optical rotary crystal can rotate the linear basis set. I'd go through the Jones algebra to be sure though.

Claude.
 
Claude Bile said:
There is no reason why the basis set orientation ought to be fixed. By my understanding the optical rotary crystal can rotate the linear basis set. I'd go through the Jones algebra to be sure though.
Claude.

For a linear basis set, one can take each individual linear orientation basis as two oppositely rotating basis set so that each orthogonal linear basis is rotated by the difference between the right and left index of refraction. This would rotate the basis set as you indicated. The amount of rotation dependent on the difference between the left and right rotary index of refraction.

However if one uses a circular basis set the light is totally right circularly (or left circularly depending on the 1/4 wave plate fast slow axis orientation) polarized when entering the optical rotary crystal. Let's assume right circularly polarized, so at best it could only interact with the right index of refraction having no left component. So the right circular polarized light's reorientation would only be the result of the right rotary index of refraction.

That is to say we would get two different results depending on the basis set used.

Where is the mistake?
 
Claude Bile said:
. I'd go through the Jones algebra to be sure though.
Claude.

I can't find the Jones matix is for an optical rotary crystal? Do you know it?
 
For a linear rotator (say, sugar water), the Jones matrices are: [[cos(δ/2)+icos(2θ)sin(δ/2) isin(2θ)sin(δ/2)], [isin(2θ)sin(δ/2) cos(δ/2)-icos(2θ)sin(δ/2)]] for cartesian basis states and [[cos(δ/2) i*exp(i2θ)sin(δ/2)], [i*exp(-i2θ)sin(δ/2) cos(δ/2)]] for circular basis states, where θ is the azimuthal angle of the fast axis and δ the phase retardation.

For a circular rotator (say, the cholesteric liquid crystal phase), the cartesian Jones matrix is [[cos(δ/2) +/-sin(δ/2)], [-/+sin(δ/2) cos(δ/2)]] and for circular basis states [[exp(-/+ iδ/2) 0],[0 exp(-/+iδ/2)]].
 
Andy Resnick said:
For a linear rotator (say, sugar water), the Jones matrices are: [[cos(δ/2)+icos(2θ)sin(δ/2) isin(2θ)sin(δ/2)], [isin(2θ)sin(δ/2) cos(δ/2)-icos(2θ)sin(δ/2)]] for cartesian basis states and [[cos(δ/2) i*exp(i2θ)sin(δ/2)], [i*exp(-i2θ)sin(δ/2) cos(δ/2)]] for circular basis states, where θ is the azimuthal angle of the fast axis and δ the phase retardation.

For a circular rotator (say, the cholesteric liquid crystal phase), the cartesian Jones matrix is [[cos(δ/2) +/-sin(δ/2)], [-/+sin(δ/2) cos(δ/2)]] and for circular basis states [[exp(-/+ iδ/2) 0],[0 exp(-/+iδ/2)]].

Hi Andy, not sure whar you mean by a linear rotator vs a circular rotator. I know you can rotate the angle of linear polarized light which I assume is what you mean by a linear rotator. What is a circular rotator?
 
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