Thin film diamond membranes bonded on-demand with SOI ring resonators

The hybrid integration of single-crystal (SC) diamond membranes with on-chip optical devices will allow the demonstration of many applications such as scalable spin register entanglement. Limited dimensions of high optical quality diamond however restrict the size and number of devices that can be fabricated on a single chip, which impedes the use of diamond in large photonic integrated circuitry. Here we show the fabrication and integration of a 1μm thick SC diamond membrane with a silicon photonic device. The quality of the diamond-silicon interface is measured using SEM and optical techniques. Silicon microring resonators are measured after integration with the diamond film and show a low excess loss of 0.4 dB and a group index dispersion that is dependent on the mode confinement in the diamond layer.