High Quality-Factor Optical Nanocavities in Bulk Single-Crystal Diamond

December 22, 2014

Reprinted by permission from Macmillan Publishers Ltd: Nature Communications ©2014

FIG. 1: Angled-etching fabrication methodology.: (a) Illustration of angled-etching used to realize free-standing structures in bulk single-crystal diamond. [From M. Burek, et al., "High quality-factor optical nanocavities in bulk single-crystal diamond," Nature Communications 5: 5718 | doi:10.1038/ncomms6718 ]

Single-crystal diamond, with its unique optical, mechanical and thermal properties, has emerged as a promising material with applications in classical and quantum optics. However, the lack of heteroepitaxial growth and scalable fabrication techniques remains the major limiting factors preventing more wide-spread development and application of diamond photonics.

SEAS grad. student Michael Burek and Prof. Marko Lončar, in cooperation with physics grad. student Yiwen Chu, Prof. Mikhail Lukin, and other scholars from Harvard and University of Waterloo, describe the technique they developed to overcome this difficulty in an article in Nature Communications. The technique is adapted from angled etching, which had been previously developed for realization of diamond nanomechanical resonators, to fabricate racetrack resonators and photonic crystal cavities in bulk single-crystal diamond. The devices feature large optical quality factors, in excess of 105, and operate over a wide wavelength range, spanning visible and telecom. These newly developed high-Q diamond optical nanocavities open the door for a wealth of applications, ranging from nonlinear optics and chemical sensing, to quantum information processing and cavity optomechanics.