TUNABLE SPECTRAL FILTRATION DEVICE

摘要

A tunable spectral filtration device includes one or more pairs of interference filters in series, each element of each pair is independently selected, independently positioned to intersect a path of converging or diverging light, and independently tilted with respect to the light path. Each filter may be a bandpass type, a shortpass type, a longpass type, a notch type, or combinations thereof. Each filter may be independently selected and tilted to tune the net spectral output of the series. The elements in a pair of filters may be tilted in opposite directions to cancel angle-of incidence dependent broadening of the spectral output of the individual filters for noncollimated light, or cancel translational shift of the transmitted light rays. The elements in a pair of filters may be tilted through orthogonal tilt axes to cancel polarization dependent broadening of the spectral output of the individual filters.