Abstract: The retainer sleeve of a three piece ferrule suitable for very small diameter optical fibers has an outside diameter threaded portion at the closed end so that, after the ferrule and optical fiber have been assembled, an outer sleeve, having a correspondingly threaded inside diameter, can be used to adjust the optical fiber end to be positioned flush with the end face of the ferrule during assembly. The design of the outside threaded sleeve for retaining the connector of two fibers to be connected is improved by inserting a shim sleeve of molded, pliable material having a "D"-shaped inside diameter to apply force to the outside diameter of the ferrules when inserted therein for reliable, concentric snug-fit.

Abstract: The fiber optic connector described herein comprises a three-piece ferrule suitable for very small optical fibers, a boot and a shoulder nut for coupling with outside-threaded split sleeve, and provides closer concentricity tolerances and low-loss transmission of light from the end of one fiber to the end of another.

Abstract: The retainer sleeve of a three piece ferrule suitable for very small diameter optical fibers has an outside diameter threaded portion at the closed end so that, after the ferrule and optical fiber have been assembled, an outer sleeve, having a correspondingly threaded inside diameter, can be used to adjust the optical fiber end to be positioned flush with the end face of the ferrule during assembly. The design of the outside threaded sleeve for retaining the connector of two fibers to be connected is improved by inserting a shim sleeve of molded, pliable material having a "D"-shaped inside diameter to apply force to the outside diameter of the ferrules when inserted therein for reliable, concentric snug-fit.