NPGS: Circular Grating (1)
The
dark center dot and the surrounding circles were exposed by the beam. The
dot has a diameter of ~1 um. The pattern has been etched by RIE to a depth
of 0.15 um into GaInAsP. About 10 circles are shown, however, the complete
pattern consists of hundreds of circles and the outside diameter is a few
hundred microns. This work was done at the National Research Council
in Canada and is described in the paper: Electronic Letters, 26 Sept. 1991,
Vol. 27, p. 1819.