How can i check that the Circular polarized beam is Right-handed or Left-handed? I use a Quarter-wave plate to make the circular polarized beam. I don't mind any method.
Just convert it to linear polarization and check if it's "right" or left angled.
@ Kim,
I assume you have a confirmed circularly polarized light (CPL). In order to know if it is LCP or RCP, first you need to convert the circularly polarized light to linearly polarized light.
Pass your CPL through a quarter wave plate followed by the rotating Polaroid. If there is complete extinction at two positions, then the incident beam is circularly polarized (this is so because a quarter wave plate will transform a circularly polarized light into a linearly polarized light). This way you can confirm that the output beam is linearly polarized light. Now do two/three experiments:
Case 1: A linearly polarized beam making an angle 45° with the z axis gets converted to a LCP after propagating through a calcite QWP; further, a LCP gets converted to a RCP after propagating through a calcite HWP. See attached picture 1.
Case 2: If the linearly polarized beam making an angle 45° with the z axis is incident on a HWP, the plane of polarization gets rotated by 90°; this beam gets converted to a RCP after propagating through a calcite QWP. See attached picture 2.
In both cases, analyze the extinction pattern of the output beam using the polaroid. If they are identical, then the beams in both cases are RCP.
But, if not, then one is RCP, another is LCP. Then how to distinguish between RCP and LCP?
Case 3: Just do the first half of the Case 1 and again analyze its extinction pattern using the polaroid.
The case (1 or 2) with which the case 3 pattern matches is then LCP, the another one is RCP.
Hope that clarifies.
The difference of the intensity of the light through a linear polarizer at two perpendicular orientations will be 0 is the beam is pure circularly polarized or fully unpolarized. So, I would also measure the linear component of polarization. The way to go is measuring the Stokes parameters: https://en.wikipedia.org/wiki/Stokes_parameters. Here two publications where they use it:
Polarization properties of light scattered off solutions of chiral molecules in non-forward direction
Angle-Resolved Polarimetry of Antenna-Mediated Fluorescence
http://scitation.aip.org/content/aip/journal/apl/107/21/10.1063/1.4936342
http://journals.aps.org/prapplied/abstract/10.1103/PhysRevApplied.4.054014
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