Arrays of both annular and square annular slots in a conducting sheet on a dielectric substrate have been fabricated photolithographically. The structures are shown to behave as bandpass filters in the far infrared, with a resonant wavelength slightly larger than the average circumference or perimeter of the slot. The measured far-infrared transmittance of the annular array is approximately 76% of that predicted by theory, while its resonant frequency agrees with theory to within 5%.
© 1989 Optical Society of America
Original Manuscript: April 18, 1989
Manuscript Accepted: June 11, 1989
Published: September 1, 1989
Peter A. Krug, W. Wright, Lewis B. Whitbourn, John C. Macfarlane, David H. Dawes, and Ross C. McPhedran, "Annular-slot arrays as far-infrared bandpass filters," Opt. Lett. 14, 931-933 (1989)