A rhomb consisting of two dense flint equilateral prisms may be used to deviate light and introduce polarization effects analogous to those of the Fresnel rhomb which displaces light. Because of the high index of the prism material (µD= 1.650), the wavelength response of the prism rhomb is superior to that of the classical low index Fresnel rhomb. Perpendicular transit of glass surfaces and invariance of the direction of the emergent light apply for both types, but in other respects the rhombs are complementary. In addition, the necessary prisms are widely available commercially.
FRANK MOONEY, "A Modification of the Fresnel Rhomb," J. Opt. Soc. Am. 42, 181-181 (1952)