Snspd with integrated aluminum nitride seed or waveguide layer

A superconducting nanowire single photon detector (SNSPD) device, comprising:

• a substrate having a top surface;
• a metal nitride optical waveguide on the top surface of the substrate to receive light propagating substantially parallel to the top surface of the substrate;
• and
• a superconductive wire on the optical waveguide, the superconductive wire being a metal nitride selected from the group consisting of niobium nitride, titanium nitride, and niobium titanium nitride, the metal nitride of the optical waveguide being different from the metal nitride of the superconductive wire.