This technology is a method designed to remove unwanted phase shifts from optical instruments to improve their performance. The method involves the manufacture and application of a layer, or multiple layers, of birefringent materials (materials with two distinct refractive indices) such that the unwanted phase shift is removed from the optical instrument. Background: Optical interference filters have been around and known for a century, and these filters have been effectively exploited technologically for at least several decades. Additionally, birefringent materials have been, and continue to be used in optics to produce various results such as, producing polarizing prisms, interference colors, and retarder plates. Because of their unique properties, birefringent materials play a large role in optical systems. This technology is more than simply using birefringent materials to reduce polarization aberration in an optical system. This is a method for determining the thickness and angle of a birefringent material to optimize the performance of an optical system by removing any phase shift in the system, what the authors call “parasitic retardance.” The birefringent material can be applied to an interference filter, or be placed on a different substrate allowing for more customization by placing the birefringent material anywhere in the optical path. Applications:
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