Silicon metasurfaces were fabricated on fused silica substrates by using sputtering, electron beam lithographyand reactive ion etching. A chromium etch mask was used to protect the silicon during plasma etching. Wedesigned a hologram with phase range of 0 - 1.17π to generate a higher order Bessel beam. The device producedthe expected beam profile and the presence of charge 3 was confirmed using a interference test. Tests on spiralplate devices were less successful owing to the thickness non-uniformity in the sputtered Si film.
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