Dear all,
 Is the Refractive index of PMMA vary with molecular weight?

 I have PMMA with Avg. MW ~ 15,000 and 95,000. The vendor sigma aldrich states
that R.I of both of these PMMA is 1.49 (nD). I'm interested in knowing the R.I
at 1550 nm.
  does anybody having an idea about the same.

regards
singh