(1) See
network transparency.
(2) An all-optical network from end to end without any electrical switching in the middle. Such networks are expected in the future; however, they add their own complexity because the lack of photonic to electrical conversion eliminates the regeneration of the signal. With all-optical switching, the distance a light signal travels one day may be different the next, and this creates a different dispersion characteristic that has to be dealt with. See
optical switch and
OEO.