Abstract: An optical device includes a substrate 60 and three prisms 10, 20 and 30. The first prism 10 is disposed adjacent to an upper surface of the substrate 60. An incoming beam aperture 65 is positioned adjacent a first surface 12 of the first prism 10, the first surface 12 extending away from the upper surface of the substrate 60. The second prism 30 is disposed adjacent to the upper surface of the substrate 60 and is spaced from the first prism 10 by a first distance. The third prism 20 is also disposed adjacent to the upper surface of the substrate 60. The third prism 20 may be spaced from the second prism 30 by the same first distance. An outgoing beam aperture 66 is positioned adjacent a first surface 22 of the third prism 20. The substrate 60 has phase changing reflective surfaces 40 and 50 along the upper surface between the first prism 10 and the second prism 30 and between the second prism 30 and the third prism 20.