Improved design of APC optical connectors with slanted angle of 12° for dispersion shifted optical fiber

This paper describes improved design criteria for a highly stable angled physical contact (APC) connector with a slanted angle of 12° for a dispersion shifted optical fiber, which is derived from the theoretical considerations based on experiments. A shift of the vertex point of the convex ferrule endface from the optical fiber axis is minimized, so that compatibility among APC connectors can be established by using a new type of stepped-ferrule developed by the author. When rotation angle between the mating ferrules was less than 4° in a circular direction, the insertion losses for the improved APC connectors consisting of stepped-ferrules were 0.23±0.45 dB, while the insertion losses for the conventional APC connectors consisting of tapered-ferrules measured 0.39±0.89 dB. It can be confirmed that slanted angle of the convex ferrule endface is required to be 12° to obtain a backreflection of less than -60 dB for the dispersion shifted optical fiber at the wavelength of 1.550 μm