Dry-etched ultrahigh-Q silica microdisk resonators on a silicon chip

Abstract

We demonstrate the fabrication of ultrahigh quality ( Q ) factor silica microdisk resonators on a silicon chip by inductively coupled plasma (ICP) etching. We achieve a dry-etched optical microresonator with an intrinsic Q factor as high as <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" id="m1"> <mml:mrow> <mml:mn>1.94</mml:mn> <mml:mo>×</mml:mo> <mml:msup> <mml:mrow> <mml:mn>10</mml:mn> </mml:mrow> <mml:mn>8</mml:mn> </mml:msup> </mml:mrow> </mml:math> from a 1-mm-diameter silica microdisk with a thickness of 4 μm. Our work provides a chip-based microresonator platform operating in the ultrahigh- Q region that will be useful in nonlinear photonics such as Brillouin lasers and Kerr microcombs.