An optical transmission system capable of monitoring the operating status of Raman-amplifier repeaters even when an optical transmission line is partly disrupted by a fiber failure. The tubular connector has upper and lower sealing elements above and below the flange interface and forms a contiguous bore for fluid communication of the fracturing fluids from the frachead to the lower tubular structure and wellhead. The semiconductor package includes dummy conductive connectors including at least dummy wiring lines, the dummy conductive connectors electrically connected to the main through substrate vias at one end, and not capable of forming an electrical connection at the other end. The note being tuned is detected automatically, thereby allowing the technician to work without constantly touching the system.