A device for manipulating the polarization of light which includes a first retarder-stack (Stack 1) that converts the polarization of input light from a first polarization basis vector (PBV1) to a second polarization basis vector (PBV2), a second retarder-stack (Stack 2) that returns the polarization of light from PBV2 to PBV1, and one or more optically functional layers between Stack 1 and Stack 2. Stack 1 has a plurality of layers, wherein the number of layers, retardation values, and orientations of layers in Stack 1 are selected to produce a PBV2 that is substantially spectrally-uniform over a prescribed range of wavelengths. PBV1 is a non-trivial eigen-polarization of combined Stack 1 and Stack 2. Stack 2 has a plurality of layers and Stack 2 is arranged in series with Stack 1. Alternatively, instead of two different stacks, a reflector may be used to produce a return pass through Stack 1.