|MadSci Network: Physics|
Hi John, It is very interesting question.. I will try to answer. I hope, I can help you with this answer.. You can find an answer your question about Orbital Angular Momentum of light in the following link.. http://www.aip.org/png/2005/229.htm On the other hand difference between polarized light and it is clear in this link. In ordinary light beam(vertically or circularly polarized light), the electric fields at every point of the cross section are in the same phase. But in a beam with orbital angular momentum, different points on the cross section are in different phases. You say:" I saw an article that someone made dust particles move in a circle when illuminated by a beam of twisted light. Is there a relatively inexpensive way of doing this as a class demonstration?" If you have a laser, it is simple.. laser------ objective ---- Specimen plane.. You can trap dust particles by this setup(above).. Good Lucks.. Best wishes
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