We show both experimentally and by numerical simulation that in the polarization interferometry of inhomogeneous birefringent objects, besides the usual interference fringes, interference blots may appear. In a light-field circular polariscope, interference blots are dark areas that may expand through a number of interference fringe. In a dark-field circular polariscope, interference blots are bright. In the vicinity of the interference blots interference fringes are deformed and their bifurcation may occur. It is shown that the cause of the interference blots is rotation of the principal birefringence axes. # 1997 Optical Society of America
展开▼