The situation was discussed when the input light is in noncentral incidence theoretically and experimentally. An optical system was built to detect the output light spot and its changes under different radial direction conditions. Fiber disturbing mode and Two Dimensional Fitting method were used here to improve the spot images captured by CCD camera. The results showed non central incidence would cause focal ratio degradation (FDR).
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.