Fabrication of Triangular Nanobeam Waveguide Networks in Bulk diamond   Using Single-Crystal Silicon Hard Masks
  A scalable approach for integrated photonic networks in single-crystal diamond using triangular etching of bulk samples is presented. We describe designs of high quality factor (Q=2.51x10^6) photonic crystal cavities with low mode volume (Vm=1.062x({\lambda}/n)^3), which are connected via waveguides supported by suspension structures with predicted transmission loss of only 0.05 dB. We demonstrate the fabrication of these structures using transferred single-crystal silicon hard masks and angular dry etching, yielding photonic crystal cavities in the visible spectrum with measured quality factors in excess of Q=3x103. 
I. Bayn, S. Mouradian, L. Li, J.A. Goldstein, T. Schr\"oder, J. Zhang,   E.H.Chen, O. Gaathon, M. Lu, A. Stein, C.A. Ruggier...
physics.optics