FILTER ARRAY WITH REDUCED STRAY LIGHT

摘要

Optical filter elements each include a parallelogram-shaped substrate with parallel light entrance and light exit surfaces and parallel slanted sidewalls slanted at an angle, and an interference filter disposed on one or both of the light entrance surface and the light exit surface. The optical filter elements are bonded together at the slanted sidewalls to form the optical filter array. Light is filtered by illuminating the optical filter array at an angle &thetas; equal to or corresponding to the angle of the slanted sidewalls. In some embodiments the angle of the slanted sidewalls corresponds to the angle-of-incidence &thetas; by Snell's law.