Refractive index profile of optical fiber by transmitted-light phase-stepping DIC microscope

摘要

The phase stepping technique was implanted into a commercial available differential interference contrast (DIC) microscope to evaluate the refractive index profile (RIP) in the optical fiber quantitatively. The measurement system can capture versatile images and phase distribution of the optical fiber. The optical path length in the optical fiber is obtained by integrate phase distribution, and with a specific algorithm the RIP is constructed. What's more, the system can be used to measure the RIP in a large scale along the axis of the optical fiber, and is insensitive to the mechanical vibration, air turbulence and temperature variation.