A network isolation apparatus is provided that permits data to be sent to a remote computer or network without a return path so that the isolated sensitive network may not be compromised. The isolation device spoofs the network so that the network believes it has a fully functional external connection. The invention has a first media converter for receiving data from a workstation on a sensitive network; this data is then passed to a second media converter and then transmitted to a remote computer. An optical signal generator sends signals to the workstation to imitate a standard transmit and receive connection, and also sends signals to the second media converter to imitate a standard transmit and receive connection. No physical connection exists for the remote computer workstation to compromise the sensitive network.