Patent ID: 8480310

Claim:
A reconfigurable fiber optic connection interface device for optical signal transmission along an optical axis which introduces less than about 1.0 dB optical loss between spaced apart first and second terminal connectors at opposite ends of a fiber optic link connection between an accessible field and an adjacent inaccessible field to facilitate the restoration of transmission through the optical link in the event of damage or defect in the accessible field portion, the interface device comprising: an interface structure along the optical axis and extending between the accessible and inaccessible fields; a replaceable fiber optic cable connector within the accessible field and including a first ferrule of a chosen nominal diameter and including an interim first optical fiber having a central core along a given optical axis within the first ferrule and forming a first terminal connector, each first fiber optic cable connector having a polished transverse surface on the end thereof facing the inaccessible field side; a non-replaceable second fiber optic cable connector along the given optical axis and originating from within the inaccessible field, the second fiber optic cable connector including a second ferrule of the chosen nominal diameter and an interior second optical fiber including a central core and forming a second terminal connector, said second fiber optic cable connector having a polished transverse surface on the end thereof facing the accessible field side; a compact adaptor seated in the interface structure concentric with the given optical axis between the first terminal connector in the accessible field and the second terminal connector in the inaccessible field, the adaptor including an alignment sleeve of cylindrical cross-section and substantially concentric about the optical axis, the alignment sleeve having an inner diameter sized to receive the ferrules of the first and second cable connectors and having a longitudinal slot along its length for physically receiving and positioning inserted ferrules of the chosen nominal diameter; at least one optical fiber transition stub disposed within the alignment sleeve between and in contact with the end faces of the first and second terminal connectors, the stub having a central fiber optic core of a longitudinal dimension chosen to make longitudinally uninterrupted contact with the cores of the first and second terminal connectors within the alignment sleeve, the stub being diametrically sized to be of the nominal diameter to fit within the sleeve and to be positioned diametrically with high accuracy by the sleeve, the stub having polished first and second end faces at angles such that the central fiber optic cores in the end faces of adjacent ferrules on inserted terminal connectors with optical continuity of less than 1.0 dB loss.