Inspecting the end surface of fiber optic connector using zoom lens and oblique illumination

摘要

In this paper, an apparatus has been designed to inspect the end surface of fiber optic connectors. A white-light high-brightness light emitting diode has been adopted to offer enough light power. Zoom lenses comprise field lens and achromatic lens with a large range of magnification from 1.25 to 60. They can be used to inspect not only the whole ferrule but also the details of the core. The illumination system has two modes: perpendicular and oblique. In oblique illumination, the relation on the maximum length of shadow along the incident direction and the angle of oblique illumination is disclosed and the curvature of shadow is drawn. Fiber undercut and protrusion can be judged whether they are satisfied the tolerance with the curvature.