Feasibility of dichroic beam splitting in the HWO coronagraph

Realization of the Habitable Worlds Observatory’s science objectives requires advancements in the technologies of optical wavefront control. Current HWO coronagraph concepts incorporate dichroic beamsplitters to facilitate parallel observations in multiple wavelength bands. A broad-band dichroic beamsplitter is a polarization element with inherently complex phase retardances that must be thoughtfully integrated into the coronagraph design. As an element in the highly-corrected optical wavefront upstream of the coronagraph, the dichroic is subject to strict manufacturing requirements. We consider the characteristics of three generic dichroic designs.