Details are given of the appearance of the-field of view when two wedges of doubly refracting material are placed in arbitrary azimuths between crossed polarizing devices. In general the field of view presents a complex pattern but simple fringe systems appear for suitable orientation of the wedges, one of which is the wellknown Babinet fringe system. Theoretical relationships are derived for the intensity distribution in the general case and for the simple cases. Photographs show how the simple fringe systems are formed out of the complex cases. A use of the patterns for detecting if the wedges of a Babinet compensator are correctly mounted is mentioned.
H. G. JERRARD, "The Formation of Fringes in a Babinet Compensator," J. Opt. Soc. Am. 39, 1031-1035 (1949)