The fabrication process of the device is quite complex. Is this a limitation for Si nanophotonics?
No. The small feature sizes of the waveguides as described in the fabrication method relies on e-beam lithography. However, these lithography steps can also be achieved using extreme UV lithography. The feature sizes required for these devices are of the same order of magnitude as the ones required for the state of the art transistors, massively fabricated using the same process fabrication steps.
