Duplex negotiation over 100Base fibre

[Jason Lixfeld <jason+nanog () lixfeld ca>]

Hello,

My understanding is that for 1G and 10G optical networks, there is no concept of half-duplex mode, but I’m unclear 
about half duplex in the 100M optical world.  Specifically, if I connect two 100Base-LX (or BX) transceivers together, 
is there a requirement for the controller(s on either side) to select between full or half duplex, either by static 
configuration, or auto-negotiation?

Thanks!