Plastic split alignment sleeves for single-mode fiber connection of MU- and SC-type ferrules

Split alignment sleeves for the single-mode optical-fiber connection of MU and SC-type ferrules were successfully fabricated for the first time with a precise injection-molding technique using a thermosetting epoxy resin. The optimum inner radii of the plastic sleeves were determined with a view to realizing both suitable gauge retention forces for the ferrules and a small fiber offset of 1 μm between them. The adapters incorporating the plastic sleeves showed excellent performance with an average connection loss of 0.09 dB and a return loss of >50 dB.