Waveguide substrates and waveguide substrate connector assemblies having waveguides and alignment features and methods of fabricating the same

Waveguide substrates, waveguide substrate assemblies, and methods for fabricating waveguide substrates are disclosed. In one embodiment, a waveguide substrate includes an input edge, an output edge, and at least one waveguide within the waveguide substrate. The waveguide substrate further includes at least one input alignment feature within the input edge adjacent to the input end of the at least one waveguide, wherein the at least one input alignment feature is fabricated from a material of the waveguide substrate. The waveguide substrate may also include at least one output alignment feature within the input edge adjacent to the output end of the at least one waveguide, wherein the at least one output alignment feature is fabricated from the material of the waveguide substrate.