Study on the use of white light interferometry for multifiber-end surface profile measurement

Abstract

An optical microscopic system for measuring multifiber-end surface based on scanning white light interferometer is described. The designed Michelson interferometric configuration in which light reflectivity of a reference flat is selected to match that of a test surface enables a better contrast of the resulting interference fringes to be recorded. A local peak comparison approach is used to determine a fractional phase from the best-focus frame of a correlogram acquired by a vertical scanning achieved with a piezoelectric translator (PZT). The whole field measurement on a 12-fiber array of the plastic ferrule with a low reflective, rough, and discontinuous surface is implemented. Experimental results show that surface geometric profile on a multifiber-end is measurable. Comparison with measurements on standard calibrated objects shows that the accuracy of the proposed system is comparable with that of existing white light interferometer and atomic force microscope.