Reflection-type confocal refractive index profile measurement method for optical waveguides: Effects of a broadband light source and multireflected lights

We have investigated the effect of a broadband light source and back reflected light in a reflection-type confocal refractive index measurement system in detail. The effect of these factors was calculated, and a detailed analysis of the error sources was thoroughly examined. We have verified our calculated results with experiments by using a broadband light source and various index matching oils.