FC/PC connector is one of the original 2.5mm ferrule technology
designs. Starting out as the FC connector (sometimes known
as face contact), the FC/PC connector (PC is sometimes referred
to as physical contact) is an improvement of the original design.
The radiused ferrule end face of the FC/PC connector allows
the optical fibers to touch, thus eliminating the air gap that
usually results with the original FC design. With the
optical fibers in contact the attenuation decreases and the
amount of light reflected back (Return Loss) to the source also
decreases. A typical FC connector has a return loss of
about -14 dB where an FC/PC connector will have a return loss
of -30dB. Using special polishing techniques an FC/PC
connector can be made to have Super PC (-40 dB) or Ultra PC
(-50 dB) return loss characteristics.