US Patent 7656527 Method and apparatus for determining concentration using polarized light

An apparatus and method for determining the concentration of chiral molecules in a fluid includes a first polarizer configure to polarize light in substantially a first plane to provide initially polarized light. A second polarizer is capable of polarizing the initially polarized light in a plurality of planes, at least one of the plurality of planes being different from the first plane, to provide subsequently polarized light. One or more receivers are included for measuring an intensity of the subsequently polarized light in one or more of the plurality of planes.