Removing the polarization artifacts in Mueller matrix images recorded with a birefringent gradient-index lens

We obtained backscattering Mueller matrix images on a cancerous tissue sample through a gradient-index (GRIN) lens and observed strong distortion in all the Mueller matrix elements. By measuring the intrinsic polarization properties of the GRIN lens, which is dominated by birefringence following a radial profile, and applying a matrix inversion method to the distorted Mueller matrix, we are able to remove the artifacts because of the birefringent GRIN lens and recover the polarization features of the sample. The results demonstrate the feasibility to take Mueller matrix measurements using GRIN lenses or other optical components with strong birefringence. (C) The Authors.