A SEM picture of already completed vertically coupled microdisk resonator. The disk resonator is air suspended and the input/output waveguides are visible. Vertical coupling allows for better control of the coupling efficiency.

A 'close-up' of the disk mesa. This high resolution picture is taken at 25,000x magnification and reveals extremely smooth sidewalls obtained with the newly developed CH4-based RIE dry etch process.

A 2.3mm deep, 0.9mm wide microring mesa formed by RIE dry etching. The smooth sidewalls allow obtaining very high quality factors in the excess of 7,000.

More than 2 micron deep microring mesa. The specula surface of the InP is free from damages.

1.5mm deep, 0.7mm wide bus waveguide mesas and a disk post between them. The purpose of the post is threefold: i) It improves the mechanical stability of the whole 3D structure; ii) It improves current/field uniformity in active devices; iii) It acts as a limiter for the higher order modes leading to single mode transmission characteristics.