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arXiv · 1208.5647

ICP polishing of silicon for high quality optical resonators on a chip

A. Laliotis·M. Trupke·J. P. Cotter·G. Lewis·M. Kraft·E. A. Hinds
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Abstract

Miniature concave hollows, made by wet etching silicon through a circular mask, can be used as mirror substrates for building optical micro-cavities on a chip. In this paper we investigate how ICP polishing improves both shape and roughness of the mirror substrates. We characterise the evolution of the surfaces during the ICP polishing using white-light optical profilometry and atomic force microscopy. A surface roughness of 1 nm is reached, which reduces to 0.5 nm after coating with a high reflectivity dielectric. With such smooth mirrors, the optical cavity finesse is now limited by the shape of the underlying mirror.

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A. Laliotis, M. Trupke, J. P. Cotter, G. Lewis, M. Kraft, E. A. Hinds. 2012-08-28. ICP polishing of silicon for high quality optical resonators on a chip. https://doi.org/10.1088/0960-1317%2F22%2F12%2F125011

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