Silicon coated mylar beamsplitter

摘要

The invention disclosed relates to an interferometer for the far-infrared which provides a high operating efficiency over the spectral range of 50 to 1000 cm-1. The beamsplitter component comprises a composite of a thin, substantially uniformly thick synthetic resin film having low far-infrared absorption, selected from polyethyleneterephthalate and polypropylene, and a thin substantially uniformly thick coating of germanium. An improved interferometer including a beamsplitter formed of the composite is also disclosed.