How does molecular chirality rotate polarized light?

[jd12345]

I have learned that molecules whose mirror images are not superimposable are chiral and it rotates the plane of polarisation by some degrees. But i don't understand how
How does unsymmetry help in rotating the plane of polarisation?

 

[AudioFlux]

this probably wouldn't answer your question, but it might be of interest to you:
http://www.chemguide.co.uk/basicorg/isomerism/polarised.html#top

 

[niallj]

The wikipedia page seems to offer quite a good explanation of what's going on: http://en.wikipedia.org/wiki/Optical_activity#Theory

I'm not sure what your level of current knowledge is, so if you have any trouble understanding that I'll be happy to explain it as best I can :)