Hinds Intruments  is selling the new 150XT Mueller Polarimeter. This instrument was developed in collaboration with New York University using the 4 Photoelastic Modulator (PEM) technology we pioneered. To my knowledge this is the first commercial full Mueller matrix polarimeter with research-grade specifications ever made available . The key element here is the sensitivity.  The instrument was developed to solve complex optical activity measurements involving chiral molecules molecules and crystals that show the tiniest bias to circular polarization. The result is a highly versatile instrument, capable of studying the transmitted complicate optical response of virtually any sample, even highly depolarizing one. The tiniest strain in a glass,  the optical rotation of a birefringent crystal, the circular dichroism of a oriented molecular aggregate,  the heterogeneous response of a  petrological sample, and many other can be studied with this polarimeter.

You can have more information about this instrument checking their brochure:

http://www.hindsinstruments.com/wp-content/uploads/150XT-Mueller-Polarimeter.pdf