A Tiny Diamond Ring

Researchers at the University of Melbourne in Australia have produced a very tiny diamond ring (see figure). It does not sport the traditional rock, but it is sculpted from high-quality single-crystal diamond. Steven Prawer presented the image of the 5-μm-diameter, 300-nm-thick single-crystal diamond ring at the March meeting of the American Physical Society in New Orleans. The ring is designed as a whispering gallery mode resonator as part of a photonic structure for the efficient collection of single photons from optically active defect centers within the diamond. The image was part of a presentation on fabrication strategies used to engineer devices from diamond. Diamond is an ideal material for fabrication of single-photon sources for quantum communications, optical fiber-based single-spin readout systems, ultrasensitive magnetometry, photonic platforms for the investigation of quantum entanglement in solid-state systems and for optical regenerators and non-linear quantum gates.