Aspirin Crystals Under Polarized Light

I have always been interested in polarized light and wondered if the foldscope could be made to incorporate it. Knowing nothing about optics, I was pretty sure that the viewing situation would be too compressed for this to work…but I still wanted to try. I purchased two plastic, linear polarizing sheets from Edmonds Optics.  I still need lots of practice creating and mounting crystals as well as focusing the foldscope after incorporating the polarizers, but the results were more dramatic than I expected.

Aspirin crystals under polarized light

Aspirin crushed between two spoons
Aspirin crystals forming in the glass. Aspirin was first dissolved in warm water and then crystals began form as the water cooled. 
First linear polarizer inserted between slide and lens.
Second linear polarizer placed behind slide. Shown at an angle to the polarizer in front.
Second polarizer orthogonal to the first polarizer. Full occlusion.
Putting the foldscope right up to the light did not work as it usually does. I had to place the light in the bottom of the jar then rest the foldscope on top. This allowed my hands freedom control the mobile phone camera.


One Comment Add yours

  1. laksiyer says:

    Beautiful. A small recommendation.The first polarizer can be stuck to the camera lens
    directly instead of between slide and lens. You can also stick it to the foldscope between the lenses of the foldscope and camera. By increasing the distance between sample and lens you are losing focus depth. I suspect this is why you lost on focus. Further I usually stick the second one to this light source. With that you can control rotation. I have never had to remove the light source for my polarizing foldscopy.. Hope to see more.

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