Appending gradient-index matching regions and apodization, which is an amplitude modulation of the rugate sinusoidal index profile, are two effective means to reduce and nearly eliminate the sidelobes. When a combination of these methods is used in the rugate design, the resulting filter will have good sidelobe suppression both near to and far from the stopband and will have high reflectance in the stopband.
© 1989 Optical Society of America
Original Manuscript: March 21, 1989
Published: December 1, 1989
William H. Southwell, "Using apodization functions to reduce sidelobes in rugate filters," Appl. Opt. 28, 5091-5094 (1989)