Measuring Mueller matrix of an arbitrary optical element with a fixed   set of polarization optics
  We have described a novel way to determine the Mueller matrix of any optical element by using projection method. For this purpose, we have used two universal SU(2) gadgets for polarization optics to obtain projection matrix directly from the experiment. Mueller matrix has been determined using the experimentally obtained projection matrix for three known optical elements namely free space, half wave plate and quarter wave plate. Experimental matrices are in good agreement with the corresponding theoretical matrices. The error is minimized as the experimental conditions remains same for all measurements since we have used a fixed set of polarization optics i.e. there is no removal or insertion of an optical component during the experiment. 
Salla Gangi Reddy, Shashi Prabhakar, A. Aadhi, Ashok Kumar, Megh Shah,   R. P. Singh and R. Simon
physics.optics