1202.4313 (Yanfeng Zhang et al.)

GaN directional couplers for integrated quantum photonics    [PDF]

Yanfeng Zhang, Loyd McKnight, Erman Engin, Ian M. Watson, Martin J. Cryan, Erdan Gu, Mark G. Thompson, Stephane Calvez, Jeremy L. O'Brien, Martin D. Dawson

Large cross-section GaN waveguides are proposed as a suitable architecture to
achieve integrated quantum photonic circuits. Directional couplers with this
geometry have been designed with aid of the beam propagation method and
fabricated using inductively coupled plasma etching. Scanning electron
microscopy inspection shows high quality facets for end coupling and a well
defined gap between rib pairs in the coupling region. Optical characterization
at 800 nm shows single-mode operation and coupling-length-dependent splitting
ratios. Two photon interference of degenerate photon pairs has been observed in
the directional coupler by measurement of the Hong-Ou-Mandel dip with 96%
visibility.

View original: http://arxiv.org/abs/1202.4313