High quality factor AlN nanocavities embedded in a photonic crystal waveguide

We present a spectroscopic study of nanocavities obtained by small modifications of a W1 waveguide in an AlN photonic crystal membrane. The AlN film containing GaN quantum dots is grown on silicon. The photonic crystal structure is defined by e-beam lithography and etched by inductively coupled plasma reactive ion etching, while the membrane is released by selective etching of the silicon substrate. The room temperature photoluminescence of the embedded quantum dots reveals the existence of even-symmetry and odd-symmetry confined cavity modes and guided modes. Cavity mode quality factors up to 4400 at 395nm and 2300 at 358nm are obtained.