An optical conversion device for a shared FTTH distribution network including first and second optical fibers and an optical processing circuit. The optical processing circuit has an input for receiving a first optical analog signal carried by the first optical fiber and an output for providing a first optical digital signal for transmission via the second optical fiber. The optical processing circuit is configured to digitize the first optical analog signal and incorporate into the first optical digital signal. The optical analog signal may be an optical signal which is modulated by an RF signal, which is the same or similar to that of existing HFC networks. High loss electrical signals are converted to low-loss optical signals propagated within the optical plant. The combined optical analog and digital protocol supports analogous communications of existing HFC networks and the optical plant minimizes cost of fiber optic upgrade.