A cost efficient and pressure resistant system for interconnecting fiber optical cables in-situ at a hydrocarbon fluid production facility comprises:—a pressure resistant light transparent window (41);—a first lens system (48A-C), which is arranged at one side of the window and configured to convert a first light beam transmitted through a first fiber optical cable (46A-C) into a collimated light beam (51A-C) that is transmitted through the window; and—a second lens system (50A-C), which is arranged at an opposite side of the window and configured to receive and reconvert the collimated light beam into a second light beam that is transmitted into a second fiber optical cable (47A-C).