Ouput Polarization of Corner Cube

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Hi:

Does the corner cube alter polarization of the input beam?
There are some (past) postings in this group stating that it does.
ZEMAX model shows it doesn't (the model is  simple: a collimated beam
is directed into the cube and the polarization of the reflected output
beam is checked out, for any input beam polarization the ouput beam has
 the same ploarization).

thanks


Re: Ouput Polarization of Corner Cube



Farsang wrote:
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The polarization is changed due to the action of the beam splitting
coating.  If you model the coating, I would expect even Zemax will show
this change.

Please visit my web site at www.richardfisher.com


Re: Ouput Polarization of Corner Cube



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Which coating?  A corner cube is TIR, only AR coating on the surface.

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Re: Ouput Polarization of Corner Cube


I forgot to mention that the corner cube modeled in ZEMAX is a three
perpendicular reflective (mirrors) surfaces object, there are no
coating on them.


Sam Goldwasser wrote:
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Re: Ouput Polarization of Corner Cube


Helpful person wrote:
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No, there's a significant change of polarization on TIR even with a
clean glass/air interface.  The s polarized light sticks out further
into the low-index medium, so its dE/dz is different at the surface,
leading to a different value of phase shift between the incident and
reflected beams.

I sometimes use this effect as a phase vernier in corner-cube
interferometers--you just rotate one cube around its 3-fold symmetry
axis.  Works up to the point where one of the cube edges starts to cross
the beam.

Cheers,

Phil Hobbs

Re: Ouput Polarization of Corner Cube



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Yes


Most likely... but when?

It's a recurring problem which has been extensively treated in the
literature.

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The corner cube will "pizza slice" the output beam.

My approach if I were to do it from scratch would be to use the Jones
matrix calculus and the Fresnel reflection coefficients.

This assumes that you know the values of the angles of incidence on
each face. I leave to you as an exercise.   ;-)

I believe that somewhere Jim Wyant (College of Optics, formerly OSC, U of A)
has treated the problem in its generality and in the context of the
interferometric
testing of corner cubes.

Following the above recipe it's very hard to do.







Re: Ouput Polarization of Corner Cube



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snip


For s and p polarization on each face.

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Depending the polarization state of the input beam (i.e. partially
polarized)
the Mueller calculus may be more appropriate.

Mueller matrices may be easily derived from the Jones matrices.
 



Re: Ouput Polarization of Corner Cube



Farsang wrote:
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A quick look shows that your uncoated alum reflector has about a 5.5%
difference in S&P reflectivity at a 45 degree AOI (I know its compound
angle) with the S being higher, this is for one reflection, so it would
be about 16% difference on the output of S & P with S being higher.

The phase difference was about 13 degrees with S being higher again on
one reflection.

I agree with Richard it should be fine in Zemax wth polarization
modeling.

Phil, a phase vernier with tilt angle, very cool - thanks for the mind
candy!

Michael
www.oscintl.com


Re: Ouput Polarization of Corner Cube


On 3/10/06 8:24 AM, in article
1142007880.742121.127900@v46g2000cwv.googlegroups.com, "Farsang"

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A cube corner (erroneously called a corner cube) will change the
polarization of outgoing light from that of the ingoing light. That even is
true for a metal corner.

Those corners using total internal reflection modify the  polarization
because the p and s components totally reflect with differing phase shifts.
As you look into the cube, each pair of circular segments provide a
different pair of what I will call pseudo polarization states that are
orthogonal. These are elliptical polarizations. They are described in an old
JOSA paper.

A metallized corner will also display a change in polarization. For a
perfect metal, it will be the same for all the sector pairs. The
polarization change is "geometrical." It has to do with how vibration
directions are defined rather than with the physics of reflection.

A simple way to see that is with a metallized roof prism. Take one of them
and place a sheet of polarizing material such as Polaroid over the
hypotenuse face. As you rotate the polarizer, you will see lightening and
darkening through the polarizer. This effect is geometrical.

Bill


-- Ferme le Bush



Re: Ouput Polarization of Corner Cube


Salmon Egg wrote:

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"Berry's phase" or "Pancharatnam's phase".  It happens when you make the
k vector describe a nonplanar figure.  The phase shift is equal to the
included solid angle of the path, which is a very non-obvious fact.  The
corresponding effect in quantum mechanics is responsible for some
spooky-looking effects, but as you say, it's just geometry.

Cheers,

Phil Hobbs

Re: Ouput Polarization of Corner Cube


On 3/10/06 8:33 PM, in article 44125310.50007@SpamMeSenseless.pergamos.net,

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I must admit that I never heard of Berry's or Pancharatnam's phase. The
geometrical phase I describe wrt metallized mirrors is probably much
simpler. It does not require complex numbers as would be necessary for total
internal reflection. It has more to do with sign convention for multiple
reflections for p and s waves.

Bill
-- Ferme le Bush



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