Measurement of insertion loss versus fiber recession in fiber optic connectors

A study was commissioned to analyze the effects of optical fiber recession/protrusion inside fiber optic connector and terminus ceramic ferrules. The purpose of fiber optic connectors is to provide a reusable, repeatable, reliable and low optical loss method of joining two separate pieces of optical fiber. In order to achieve these goals, various standards bodies have devised recommendations for the geometry of the polished endface of these connectors including the Spherical Fiber Height [1]. Fiber height is also referred to as fiber recession when the fiber is below the surface of the connector's ceramic ferrule and is typically measured with an optical interferometer specially designed for the purpose of measuring connector endface geometry. A typical acceptable range for fiber height is from -125 to +50 nanometers. The purpose of this study is to examine the optical performance when the Spherical Fiber Height is not within the recommended range.