| Abstract: | A hybrid spiral waveguide geometry is proposed that exhibits essentially
zero curvature (i.e., infinite bend radius) at the center of the spiral
(similar to a Fermat spiral), with the curvature then increasing in value
as the spiral moves outward. Advantageously, as the spiral moves away
from the center, the spacing between adjacent waveguides quickly
approaches a constant value (similar to an Archimedean spiral). This
hybrid spiral structure has been found to allow for a high density
waveguide to be created with lower loss and requiring a smaller size than
many conventional spiral configurations and finds use in optical delay
lines, amplifiers and arrayed waveguide gratings. |