Rugate filters are optical thin film interference structures with sinusoidal refractive index profiles. Two-wavelength reflection filters have been fabricated by codeposition of SiO2 and TiO2. Composition modulation was monitored and controlled using quartz crystal rate controllers. The resulting filters exhibited two well-defined stopbands. Microscopic examination revealed that the structure is glasslike without pronounced thin film microstructure.
© 1989 Optical Society of America
Original Manuscript: July 12, 1988
Published: July 15, 1989
William J. Gunning, Randolph L. Hall, Frank J. Woodberry, W. H. Southwell, and Natalie S. Gluck, "Codeposition of continuous composition rugate filters," Appl. Opt. 28, 2945-2948 (1989)