An optical filter for the selective attenuation of specific wavelengths of
light includes at least one spectrally dispersive element, such as a
diffraction grating or prism, in combination with an optical filter. A
dispersive element separates broadband light into a constituent
wavelength spread in angle space. An optical filter, or filter array, can
block and/or attenuate specific wavelengths or wavelength ranges of
interest while the light is angularly dispersed. A second dispersive
element can recombine this filtered, separated wavelength fan of light
into a coaxial broadband beam having a smoother intensity profile than
the unfiltered beam.