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Chemistry Forums for Students => Undergraduate General Chemistry Forum => Topic started by: ollypf on February 18, 2021, 03:03:35 PM

Title: Can a homemade polarimeter use circular polarizing lenses?
Post by: ollypf on February 18, 2021, 03:03:35 PM

Hey, I have been building a polarimeter for my organic chemistry project. I can’t seem to find out anywhere if the lens has to be linear polarizing or it can be circular polarizing. Everything that comes up on search is about photography. Logically, I don’t think they should work with the light rotating that way, but I don’t know that much about the topic haha. I already ordered circular ones and have to know soon if I need new ones. Any advice would be appreciated!

Title: Re: Can a homemade polarimeter use circular polarizing lenses?
Post by: Corribus on February 19, 2021, 11:58:02 AM

You'll want optics that create plane polarized light, one before the sample and one after the sample. A polarimeter measures the rotation of plane polarized light. Your first optic creates plane polarized light. The second optic only permits plane polarized light to pass through. And you need something that measures the angle of the second polarizer with respect to the first, to measure the angle the polarization plane is rotated by the sample.