Fiber connector end face analysis by interference method

High quality fiber optic connectors are a crucial part of any fiber optic system. Back reflection or return loss in fiber connectors is the amount of the light reflected back towards the source relative to the forward signal. The primary cause of the back reflection is a discontinuity in the refraction index of the fiber (Fresnel reflections). Changing the connector end face by polishing can control this effect. The grain of the end face of the physical contact connectors after polishing should not exceed 0.035mkm. We check this by using a microinterferometer in which the fringes and researched surface are observed simultaneously.