Ok, poor question on my part, but a great answer. Thanks! Yes, wavelength-division multiplexing can expand the capacity of a single strand.

I meant, packet switching.

Switching packets of photons would be done by transitioning from transparent to opaque/inverted polarity/shifted wavelength/etc.

I'm way out of my depth here but an interferometer seems like one method that current research is looking at to accomplish that. What do you think looks the most promising?